Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 11/17/11
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1054 PM MST MON NOV 14 2011
.AVIATION...
VFR CONDITIONS SHOULD CONTINUE OVER THE KALS...KCOS AND KPUB TAF
SITES TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 517 PM MST MON NOV 14 2011/
UPDATE...
UPDATED GRIDS TO ACCOUNT FOR ENDING OF RED FLAG WARNING.
PREV DISCUSSION... /ISSUED 307 PM MST MON NOV 14 2011/
SHORT TERM...
(TONIGHT AND TUESDAY)
CRITICAL FIRE WEATHER CONDITIONS WILL CONTINUE ACROSS EL PASO AND
PUEBLO COUNTIES FOR THE NEXT COUPLE HOURS...DUE TO A COMBINATION OF
LEE TROFFING AND NORTHWEST FLOW ALOFT. MODELS DID NOT HAVE A VERY
GOOD HANDLE ON DEW POINTS TODAY...AS DRY AIR BEHIND YESTERDAY`S
DEPARTING SYSTEM TANKED DEW POINTS INTO THE SINGLE DIGITS TO AROUND
10 DEGREES ALONG THE LOWER EASTERN SLOPES OF THE SOUTHEAST MOUNTAINS
AND I-25 CORRIDOR. RUC13 AND HRRR WERE THE FIRST TO CATCH ON TO
THIS. SFC PRESSURE GRADIENT IS TIGHTEST ACROSS NRN PORTIONS OF THE
AREA WHICH WILL KEEP BREEZY WEST WINDS ACROSS PUEBLO AND EL PASO
COUNTY THROUGH THE LATE AFTERNOON/EARLY EVENING. FARTHER EAST OF
THE I-25 CORRIDOR...HAVE SEEN SOME OCCASIONALLY BREEZY WEST WINDS
KICK IN AS FAR EAST AS LHX...HOWEVER THEY HAVE BEEN LESS
PERSISTENT...AND THINK THAT IT WON`T QUITE MAKE THE 3 HOUR DURATION
REQUIRED FOR A RED FLAG WARNING. WINDS SHOULD DIMINISH AFTER 00Z.
WITH THE DRY AIR IN PLACE...CHALLENGE WILL BE HOW COOL LOW
TEMPERATURES WILL DROP. LOWER EASTERN SLOPES NEAR THE MTS SHOULD
CONTINUE TO EXPERIENCE SOME WESTERLY DRAINAGE WINDS OVERNIGHT WHICH
SHOULD KEEP MIN TEMPS AROUND 40. HOWEVER WHERE WINDS
DECOUPLE...EFFICIENT RADIATIONAL COOLING WILL ALLOW TEMPS TO DROP
QUICKLY. HAVE GONE ABOVE GUIDANCE FOR LOWS NEAR THE MTS...BUT KEPT
MINS ON THE LOWER SIDE OF GUIDANCE ELSEWHERE.
FOR TOMORROW...NEXT WEAK WAVE EMBEDDED IN NW FLOW ALOFT WILL
APPROACH THE AREA. SHOULD SEE SCATTERED SNOW SHOWERS RAMP UP FOR
THE CENTRAL MTS. WINDS SHOULD BE LIGHTER TOMORROW ACROSS THE
PLAINS...THOUGH A COLD FRONT WILL APPROACH NRN PORTIONS OF THE AREA
IN THE AFTERNOON. OVERALL TEMPS SHOULD NET A FEW DEGREES COOLER
ACROSS THE PLAINS. ISOLATED SNOW SHOWERS MAY SPREAD ACROSS NORTHERN
EL PASO COUNTY IN THE LATE AFTN AS UPPER JET DYNAMICS MOVES IN ALOFT
AND FRONT MOVES INTO THE AREA. THINK MAIN THREAT WILL BE IN THE
EVENING...SO WILL MAINTAIN THE 10 POPS FOR NOW. -KT
LONG TERM...
(TUESDAY NIGHT-MONDAY)
TUESDAY NIGHT-WEDNESDAY NIGHT...MODERATE TO STRONG NORTHWEST FLOW
CONTINUES ACROSS THE REGION AS ANOTHER EMBEDDED SHORT WAVE
TRANSLATES ACROSS THE ROCKIES. MODEL SOUNDINGS AND CROSS SECTIONS
CONTINUE TO INDICATE A FAIRLY SHALLOW LAYER OF MID LEVEL MOISTURE
STREAMING ACROSS THE AREA THROUGH TUESDAY NIGHT DIFFER ON LOCATION
OF BEST UVV WITH WITH PASSING JET CORE. AT ANY RATE...WITH CONTINUED
GOOD OROGRAPHIC FLOW...BEST POPS TO REMAIN ACROSS THE EASTERN
SAWATCH AND MOSQUITO RANGES EARLY TUESDAY EVENING WITH ANY SNOWFALL
DIMINISHING OVERNIGHT TUESDAY. HAVE ALSO KEPT SLIGHT POPS ACROSS THE
PIKES PEAK REGION AS WELL...WITH THE POTENTIAL FOR A QUICK SHOT A
FEW SNOW SHOWERS TUESDAY EVENING. TEMPERATURES LOOK TO BE GENERALLY
BELOW SEASONAL AVERAGES WEDNESDAY...ESPECIALLY ACROSS THE PLAINS
WITH LOW LEVEL UPSLOPE FLOW.
THURSDAY-FRIDAY...MODERATING WESTERLY FLOW PROGGED ACROSS THE REGION
THROUGH THE END OF THE WORK WEEK AS JET STREAM LIFTS ACROSS THE
NORTHERN TIER OF STATES. DRY WEATHER WITH TEMPS WARMING BACK TO
ABOVE SEASONAL AVERAGES CAN BE EXPECTED. LEE TROUGHING ON THE PLAINS
WILL ALSO LEAD TO BREEZY CONDITIONS AND THE POTENTIAL FOR CRITICAL
FIRE WEATHER CONDITIONS.
FRIDAY NIGHT-MONDAY...MODELS COMING INTO THE BETTER AGREEMENT WITH
SNOWFALL BECOMING INCREASINGLY LIKELY LATE FRIDAY NIGHT AND SATURDAY
ALONG AND WEST OF THE CONTDVD AS WEST TO SOUTHWEST FLOW INCREASES
AHEAD OF AN EASTERN PACIFIC SYSTEM DIGGING ACROSS THE GREAT BASIN
FRIDAY WHICH CONTINUES TO LIFT OUT ACROSS THE STATE ON SATURDAY.
PASSING WAVE LOOKS TO BRING ANOTHER BOUT OF WINDY TO VERY WINDY
CONDITIONS TO THE EASTERN MTS AND PLAINS FRIDAY NIGHT AND SATURDAY
WITH A STRONG COLD FRONT BRINGING IN A MODIFIED ARCTIC AIRMASS TO
THE AREA ON SUNDAY. AT THIS TIME...THE BULK OF THE COLDEST AIR LOOKS
TO REMAIN WELL EAST ACROSS THE CENTRAL HIGH PLAINS...THOUGH WILL
NEED TO CONTINUE TO MONITOR. -MW
AVIATION...
VFR CONDITIONS EXPECTED AT ALL 3 TAF SITES THROUGH TUESDAY. SOME GUSTY
SOUTHWEST WINDS WILL CONTINUE AT THE TAF SITES UNTIL 01-02Z...WITH
LIGHT DRAINAGE WINDS EXPECTED OVERNIGHT. ON TUESDAY...WEAK FRONT
WILL DROP THROUGH THE PLAINS WITH WINDS AT KCOS STAYING OUT OF THE
NW DURING THE MORNING. FOR KPUB...FRONT WILL LIKELY BACKDOOR IN
WITH WINDS SWITCHING AROUND FROM THE EAST DURING THE LATE
AFTERNOON. MAIN NORTHERLY SURGE WITH THE FRONT WILL DROP IN
TOMORROW EVENING BRINGING A BRIEF PERIOD OF GUSTY NORTH WINDS OF 15
TO 25 KTS. MEANWHILE...WINDS AT KALS WILL REMAIN LIGHT OVERNIGHT
BEFORE INCREASING FROM THE SOUTH AROUND 10 KTS TUES AFTN. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1243 PM EST TUE NOV 15 2011
.SYNOPSIS...
A FRONTAL BOUNDARY FROM THE ADIRONDACKS SOUTHWEST TO CENTRAL INDIANA
WILL SLIDE DOWN INTO SOUTHERN SECTIONS OF NEW JERSEY AND PENNSYLVANIA
LATE THIS AFTERNOON. THEN A SERIES OF LOW PRESSURE SYSTEMS WILL MOVE
ALONG THE FRONT PASSING OFF THE MID ATLANTIC COAST BETWEEN LATE
TONIGHT AND THURSDAY MORNING. THEREAFTER HIGH PRESSURE OVER THE
SOUTHERN PLAINS WILL STRENGTHEN AS IT ARRIVES IN VIRGINIA FRIDAY...
MOVING OUT TO SEA DURING THE WEEKEND. A SOUTHEASTWARD MOVING COLD
FRONT WILL CROSS THE MID ATLANTIC STATES SUNDAY NIGHT. HIGH PRESSURE
BUILDS ACROSS SOUTHEAST CANADA EARLY NEXT WEEK AS LOW PRESSURE
MOVES INTO THE OHIO VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS TO THE NORTH AND WEST OF THE FORECAST AREA ASSOCIATED WITH A
SLOW MOVING FRONT CONTINUE TO MAINLY BE FOCUSED TO OUR
NORTHWEST.THE FRONT AND ASSOCIATED SHOWERS WILL CONTINUE TO SLIDE
SE AND BRING CLOUDS AND SCAT SPRINKLES TO THE REGION THIS
AFTERNOON. HAVE ADJUSTED POPS DOWN TO BETTER REFLECT RADAR TRENDS
THAT KEEP THE MAJORITY OF THIS ACTIVITY TO OUR NORTHWEST. THIS
MATCHES WELL THE SREF AND LATEST RUC MODEL RUNS. ALSO LOWERED
DEWPOINTS SOME TO BETTER MATCH WITH CURRENT OBSERVATION PERHAPS
EVEN A TOUCH TO LOW IN SPOTS. CLOUDS WILL HOLD READINGS IN THE 60S
IN MOST OF THE REST OF THE REGION WITH UPPER 50S OVER THE SRN
POCONOS. THESE READINGS ARE STILL WELL ABOVE NORMAL FOR MID
NOVEMBER. WINDS WILL MOSTLY BE SW OR S EARLY TODAY THEN SWITCH TO
MORE OF A WRLY DIRECTION BY EVENING. CURRENT THINKING IS
INCREASING RAIN CHANCES WITH THE LOW PRESSURE SYSTEM ALONG THE
FRONT WILL NOT ENTER THE REGION TILL AFTER 00Z WHICH MATCHES UP
WELL WITH MODEL TIMING. OVERALL QPF ALSO LOOKS QUITE LIGHT TODAY
PERHAPS A FEW HUNDREDTHS WEST AND NORTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
THE FRONT WILL REMAIN ACROSS THE AREA WHILE A WAVE OF LOW PRESSURE
MOVES ALONG IT TONIGHT. THE APPROACHING LOW WILL ENHANCE THE CHC FOR
RAIN TONIGHT...ESPECIALLY LATE. QPF TOTALS OF UP TO ONE-HALF INCH
MAY OCCUR TONIGHT WITH MOST OF IT AFTER MIDNIGHT. LOWS TONIGHT WERE
MOSTLY LIFTED FROM THE NAM-MOS WITH 50S OVER MOST AREAS AND SOME
UPPER 40S OVER THE SRN POCONOS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A BRIEFLY SHARPENING TROUGH ALOFT MOVES FROM THE NORTHERN PLAINS
WEDNESDAY THROUGH THE GREAT LAKES AND NORTHEAST USA THURSDAY WITH
RIDGING BUILDING ACROSS THE EASTERN THIRD OF THE UNITED STATES
THIS WEEKEND. THAT WARM RIDGE WILL WEAKEN NEXT WEEK AS DISTURBANCES
MOVE NORTHEASTWARD FROM THE PLAINS INTO THE NORTHEAST USA.
A SEE SAW TEMPERATURE REGIME WILL PREVAIL THIS EXTENDED PERIOD WITH
ABOVE NORMAL TEMPERATURES WEDNESDAY SLIDING TO BELOW NORMAL BY FRIDAY
THEN ABOVE NORMAL SUNDAY BEFORE POSSIBLY COOLING EARLY NEXT WEEK.
THE 16 DAY DRY SPELL THAT BEGAN OCTOBER 30 IS ABOUT TO COME TO A
RATHER WET ENDING. BLAKESLEE IN CARBON COUNTY PA REPORTED .05
YESTERDAY FROM THE MIDDAY MONDAY SHOWERS THAT GRAZED THE POCONOS
AND THE TIP OF NNJ.
NOW YOU SEE THE MOISTURE PLUME FROM TEXAS THRU THE OHIO VALLEY INTO
THE NORTHEAST USA. THE SLOWLY EVOLVING TROUGH INTO THE GREAT
LAKES THE NEXT 48 HOURS WILL HAVE RIPPLES OF ENERGY ALONG THE JET
STREAM CAUSING PERIODS OF HEAVY SHOWERS WITHIN THE MOIST PLUME.
THE DAILIES BELOW...
WEDNESDAY...HPC QPF...A PERIOD OF HEAVY SHOWERS...ESPECIALLY IN
THE MORNING. DID NOT CONVERT THE ELEMENT RAIN BACK TO SHOWERS BUT
SEE QUITE A BIT OF VARIABILITY IN INTENSITY THRU THE DAY AS WELL
AS POSSIBLY SEVERAL HRS OF NO RAIN. ONE OF THE PROBLEMS IS THE
FRONTAL SYSTEM BISECTING THE FCST AREA...ROUGHLY NEAR THE I95
CORRIDOR. COOLER TO THE NORTHWEST BUT IT COULD BE QUITE MILD AND
UNSTABLE JUST TO THE SE AND COULD SEE THUNDER IN DE COASTAL SE NJ
THAT MIGHT BE STRONG ENOUGH TO WARRANT STATEMENTS OR AN SMW. THE
MODEL CAMPS ARE NCEP VS ALL THE OTHERS AND AM SIDING WITH ALL THE
OTHERS IN THIS SCENARIO....ESPECIALLY UK/ECMWF. TEMPS MAY SOAR
INTO THE 70S FOR A TIME WED MIDDAY IN SRN DE. ALL FCST ELEMENTS ON
WEDNESDAY WERE 50/50 NCEP MOS THEN BLENDED 50 PCT WITH THE RGEM
WHICH REPRESENTED THE WARMER MORE UNSTABLE SCENARIOS DEPICTED BY
THE ECMWF/UKMET/GGEM AND RGEM.
HOW FAST DOES THE RAIN END IN THE NW PORTION OF THE FCST AREA WED
NIGHT. UP FOR DEBATE AND AM NOT BUYING A FAST END. TOO MUCH
INTENSIFICATION OF THE TROUGH ALOFT TO THE WEST KEEPS THE FLOW
PARALLEL TO THE FRONT WITH RIPPLES OF JET STREAM ENERGY AND RRQ OF
THE UPPER LVL JET AT LEAST THRU 10Z THURSDAY HERE...THAT MEANS
WAVES OF PRES FALLS/WEAK BUT RATHER MOIST WAA AND PROBABLY NOT ONE
BIG LOW PRES SYSTEM. EACH WAVE A LITTLE FURTHER S THAN THE PREVIOUS.
THURSDAY...UNCERTAINTY REGARDING BACK EDGE OF THE PCPN SHIELD BUT
THICKNESSES WILL BE COOLING AND WHILE THE BL TEMPS WILL BE MARGINAL...
ONE COULD ENVISION A LITTLE SNOW AT THE TAIL END ACROSS THE POCS
AND FAR NW NJ. USE OF THE BOX WX TOOL PERMITTED SNOW USING BLENDED
NCEP THICKNESS FIELDS AND BLENDED NCEP MOS TEMPS WITH THE ECMWF 2M
TEMPS. THE QUESTION...WILL THERE BE ANY PCPN IN THE COLDER AIR
AFTER 12Z THU AND AM UNSURE. HOWEVER...AM NOTING EACH NCEP CYCLE
KEEPS DRAGGING OUT THE PCPN SCENARIO LONGER AND LONGER.. MORE IN
KEEPING WITH ECMWF/UKMET. THINK THIS MIGHT GET A LITTLE INTERESTING
THURSDAY MORNING...ESP SINCE GEFS/SREF MEMBER TRENDS ARE SHOWING A
SLOWLY INCREASING MEMBER TREND OF WET MELTING SNOW IN THE LAST FEW
HRS OF THE EVENT IN NE PA.
ANYWAY...THINK PARTIAL CLEARING WILL DEVELOP THU AFTN W BELOW NORMAL
MAX TEMPS. GUSTY NW WINDS 20 TO 25 MPH DEVELOP LATER IN THE
AFTERNOON.
FRIDAY...SUNNY BUT CHILLY...COLDEST DAY OF THE WEEK WITH BELOW
FREEZING TEMPS MOST OF THE AREA TO START THE DAY. LIGHT WIND PERMITS
LITTLE MIXING AND THEREFORE TEMPERATURES WILL STRUGGLE TO RISE
DESPITE ALL THE SUN.
SATURDAY...WARM AIR ADVECTION BEGINS WITH SOME CLOUDINESS AND A
SLIGHTLY MILDER AFTERNOON AFTER ANOTHER CHILLY START.
SUNDAY...APPROACHING COLD FRONT MAY TRIGGER ISOLATED SHOWERS IN A
BRIEFLY STRONG WARM ADVECTION PATTERN. THE ASSOCIATED CLOUD COVER
AND SMALL RISK OF A SHOWER SEEM TO MINIMIZE THE POTENTIAL WARMUP.
MONDAY-TUESDAY...PROBABLY COOLER OR COLDER AS HIGH PRESSURE BUILDS
INTO SE CANADA AND BEGINS A CHILLY BL DRAIN AHEAD OF LOW PRES
MOVING INTO THE OHIO VALLEY. HIGHEST POPS FOR NOW EARLY NEXT WEEK
ARE MONDAY NIGHT WHEN THERE IS A LOW PROBABILITY OF ICE OR SNOW MIX
IN THE POCS AND FAR NW NJ. SCENARIO HAS QUITE A BIT OF UNCERTAINTY
REGARDING LATITUDE TRACK OF THE SFC LOW WHICH COULD MEAN LARGE
TEMPERATURE BUST POTENTIAL IN OUR FCST AREA. GFS MEX GUIDANCE SEEMS
TO BE ON THE WARM SIDE FOR NOW. DESERVES TO BE MONITORED IN A FEW
DAYS TO SEE IF TRENDS ARE COLDER OR WARMER. AM PRETTY CONFIDENT OF
A PCPN EVENT EARLY NEXT WEEK. GFS MEX-MOSGUIDE POPS ARE A DECENT START ON
THIS DAY 7 ISH PERIOD OF WX.
HYDRO: WIDESPREAD ONE HALF TO 2 INCH RAINS ANTICIPATED BETWEEN 9 AM
TODAY AND 9 AM THURSDAY...MOST OF IT WEDNESDAY.
SVR: STILL A CHC OF A STRONG TSTM WITH GALE FORCE GUSTS SE EDGE
OF THE FCST AREA WED MORNING OR MIDDAY...COASTAL DEL AND FAR S NJ
WEDNESDAY. ECMWF/GFS SWI INDICATED AND SWODY2 HAS THUNDER.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
A LARGELY VFR FORECAST TODAY AT THE TERMINALS. A SLOW MOVING FRONT
FROM THE WEST WILL CROSS THE AREA TODAY. THE INCREASING CLOUDS EARLY
TODAY SHOULD REMAIN VFR AND THE PRESENT SHOWERS TO THE WEST WILL
PROBABLY FALL APART SOMEWHAT AS THEY ARRIVE. THESE SCATTERED SHOWERS
WILL BE OVER THE AREA MUCH OF TODAY AND THIS EVENING BEFORE A MORE
ORGANIZED AREA OF RAIN AND LOWER CIGS ARRIVE LATER TONIGHT. EXACT
TIMING OF THE SHOWERS TODAY A DIFFICULT FCST SO PLENTY OF VCSH USED
FOR NOW.
OUTLOOK...
WEDNESDAY...WIDESPREAD MVFR TO SCT BRIEF IFR CONDS IN BANDS OF SHOWERS.
SOME OF THE RAIN CAN BE HEAVY. S OR SW WINDS ALONG OR EAST OF THE
ILG-PHL-EWR CORRIDOR THRU MIDDAY BECOMING NW TO N EVERYWHERE BY
LATE IN THE DAY. CONDS IMPROVING TO VFR CIGS FM NW TO SE AT NIGHT
WITH THE TRAILING BACK EDGE OF ANY REMAINING IFR BY DAWN THURSDAY
FROM KACY TO KGED SOUTHWARD.
THURSDAY...CHANCE OF MVFR CONDS IN PCPN DURING THE MORNING...MAINLY
RAIN AND MAINLY ALONG THE COAST. OTRW VFR. GUSTY NW WINDS 20 TO
25 KTS IN THE AFTN.
FRIDAY...VFR. LIGHT W WIND.
SATURDAY...VFR THOUGH MVFR CIGS MAY DEVELOP AT NIGHT. WIND BECOME
S-SW G15 KTS.
&&
.MARINE...
THE SCA FLAG FOR DEL BAY HAS BEEN DROPPED. WINDS CONTINUE TO
DECREASE AND ONLY A FEW GUSTS UP TO 20 KT WILL PROBABLY OCCUR THIS
MORNING. FOR THE OCEAN WATERS...THE SCA FLAG WILL BE IN EFFECT
UNTIL 6 PM SINCE IT MAY TAKE UNTIL THEN FOR THE SEAS TO RELAX
BELOW 5 FT. THE WINDS ON THE OCEAN WILL PROBABLY DECREASE BELOW 25
KTS BEFORE THAT.
OUTLOOK...
WEDNESDAY...NO HEADLINE ANTICIPATED EXCEPT POSSIBLY AN SCA FROM
THE SNJ COAST SOUTHWARD ALONG THE ATLC DEL WATERS BOTH IN MORNING
SW FLOW AND THEN CAA NNW FLOW LATE IN THE EVENING. CONFIDENCE
BELOW AVG ON WIND DIRECTION/SPEED AND TIMING OF THE CFP.
THURSDAY INTO FRI MORNING...INTERMITTENT SCA CONDITIONS ANTICIPATED
WITH ATLC SEAS AT OR BELOW 5 FT BUT OCNL NW GUSTS NEAR 25 KTS. WIND
FIELDS LOOK A LITTLE LIGHTER THAN WHAT WAS MODELED THE PAST SEVERAL
NIGHTS...SO IT MIGHT BE A MARGINAL CONDITION.
FRI AFTERNOON INTO SATURDAY...NO HEADLINE EXPECTED ATTM.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR
ANZ450>455.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...GAINES/KLINE/O`HARA
SHORT TERM...O`HARA
LONG TERM...DRAG
AVIATION...DRAG/O`HARA
MARINE...DRAG/O`HARA
AREA FORECAST DISCUSSION...
NWS TALLAHASSEE FL
250 PM EST Tue Nov 15 2011
.Synopsis...
19Z water vapor and H4 RUC analysis shows an upper level pattern
dominated by broad troughing across much of the CONUS. Our forecast
area resides on the boundary between this troughing and an upper
ridge axis over the FL Peninsula. This ridge axis will suppressed
further south and east over the next 24 hours. Other features of
note include a shortwave impulse embedded within the main flow over
eastern Texas, and a series of weaker impulses working down the
backside of the trough over the inter-mountain west.
At the surface, subtropical ridge axis extends from off the GA/NE FL
coast westward along the I-10 corridor. To our north and west we
find a quasi-stationary frontal boundary extending across Arkansas
and the Tennessee Valley. Weak WAA regime developing over the region
in advance of the Texas shortwave is supporting the development of a
few isolated low-topped sprinkles/showers this afternoon.
&&
.Short Term (Tonight through Thursday night)...
Tonight, shortwave impulse over Texas will shear out as it lifts
northeastward across the lower MS valley. Although this energy will
be de-amplifying, the combination of modest overspreading synoptic
support and the low level WAA/upglide regime should be enough to
support widely sct-sct showers breaking over the area. Still appears
as though the western zones will have the best chances for showers
with closer proximity to the passing synoptic support/height falls.
However, the general broad nature of the upglide suggests at least a
chance of widely sct showers after midnight for the eastern zones as
well. Any activity should be generally on the light side and be
brief in nature. For these reasons only light rainfall accumulations
of generally under 1/10th of an inch are expected. The pattern
suggests areas of lower stratus/fog developing by the later evening,
and especially after midnight. Will include areas of dense fog in the
grids after 06Z. The southerly flow will also result in a warm
overnight period with low temps failing to fall out of the 60s.
Wednesday/Wednesday night,
Initial shortwave impulse will continue to shear out while passing
to our north during the morning hours of Wednesday. With the
synoptic forcing weakening the first half of the day, any sct
showers will be the result of the continuing upglide and therefore
on the shallow/light side. Weak instability early in the day will
also limit the overall convective coverage/intensity. During the
second half of the day and into the evening hours the chances for
some more robust convection increase, especially over the
western/northern half of the area. The next mid/upper level impulse
will be amplifying as it approaches from the west. Diurnal heating
along with this increasing synoptic support will be the trigger for
any storms. An isolated strong/severe storm can not be ruled out,
however dynamic/kinematic parameters are all rather marginal for
organized updrafts. Into the overnight hours, cold front will shift
eastward across the area with showers slowly coming to an end after
its passage. The guidance ensemble suggests that the shower/storm
coverage may increase for a time ahead of the front over the eastern
half of the area. There is some support for this, as the better deep
layer QG forcing becomes briefly aligned with RRQ dynamics
associated with a strengthening upper level jet streak. For now will
go with 50% areal coverage PoPs over the eastern zones Wednesday
night. However, these numbers may on the low side should confidence
in the described synoptic setup increase.
Thursday,
Cold front will be exiting to our east during the morning hours
ending any lingering showers toward Mayo/Cross City. Clearing skies
will follow with a mostly sunny and seasonable afternoon for all
zones. A much drier airmass in place by the end of the day will set
up a cool night with low temperatures generally in the lower to
middle 40s. Unlike several days ago, the surface high behind this
front will pass well to our north helping to keep the surface
gradient tight. This less favorable high position is likely to
prevent boundary layer decoupling and therefore do not anticipate a
frost threat Thursday night for even the normally colder locations.
&&
.Long Term (Friday through next Tuesday)...
The large scale long wave pattern commences with a trough developing
just off west coast with another trough lifting NE across New
England into adjacent Canada. in between, a low amplitude almost
zonal flow dominates rest of Conus. At surface, in wake of cold
front that was racing SEWD across srn tip of FL, strong 1032mb high
moves SE to over VA with ridge building SWWD across NRN Gulf region
and providing dry NLY flow, rising heights and strong subsidence.
During the rest of the forecast...Wrn trough significantly deepens
SEWD over Wrn states while Ern trough lifts further NEWD. This
allows weak ridging to build EWD over NRN Gulf. By Sat...flow ahead
of advancing trough and newly formed Gulf of Mex high becomes
increasingly SWLY with increasing higher level clouds over local
area. Some light rain possible mainly offshore. However, building
Gulf high shunts deeper moisture just to to our N thru end of
period. At surface, high moves NEWD and well offshore with ridging
WSW over NRN Gulf. This favors locally breezy NE flow rest of
weekend. By Monday, high influence begins to erode allowing for an
increase in low level moisture.
Will go with nil pops thru the period. In wake of front, minimum
temps will commence to 5 to 7 degrees below Thurs night then rising
to around climo Fri night and 5 to 8 degrees above climo Sat thru
Mon nights. Maximum temperatures commence at or slightly above climo
Fri thru Sat then under onshore flow, 6 to 8 degrees above climo
Sun-Tues. Average inland min/max temps are 46/71 degrees.
&&
.Aviation...(through 18Z Wednesday).
Moist flow off the gulf will keep the MVFR cigs in place through the
afternoon. Expect IFR conditions at all terminals overnight with low
CIGS and VSBY. Conditions will approach airport minimums at KVLD,
KECP, KTLH. Slightly better conditions are expected at KABY and KDHN
where atmosphere will be a bit more stirred up ahead of the
approaching front. Scattered thunderstorms will be possible by
Wednesday morning at KABY and KDHN.
&&
.Marine...
Southerly flow will continue through Wednesday ahead of an
approaching cold front. Winds may approach cautionary levels at
times, especially Wednesday afternoon. The cold front will cross the
forecast waters Wednesday night with winds shifting to the Northwest
in its wake. Winds and seas are expected to quickly increase to
advisory levels early Thursday, and then linger through Thursday
night. A more prolonged period of elevated easterly flow is then
expected into the upcoming weekend.
&&
.Fire Weather...
A very moist airmass will remain in place through
Wednesday with no fire weather concerns. A drier airmass will spill
into the region on Thursday in the wake of a cold front. Humidity
values are forecast to drop to near critical levels during the
afternoon. However, critical durations are not expected to be met at
this time, and dispersions are currently forecast to remain just
below critical limits.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 65 81 62 74 42 / 30 30 50 10 0
Panama City 67 78 60 72 45 / 40 50 50 0 0
Dothan 65 83 56 69 40 / 40 60 50 0 0
Albany 65 83 59 71 40 / 40 50 50 10 0
Valdosta 64 81 63 74 43 / 20 30 50 10 0
Cross City 63 80 66 77 46 / 20 30 50 30 0
Apalachicola 68 75 63 73 44 / 30 40 50 10 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
MROCZKA/CAMP/BLOCK
AREA FORECAST DISCUSSION...
NWS TALLAHASSEE FL
1020 AM EST Tue Nov 15 2011
.Update...
14Z water vapor and H4 RUC analysis shows an upper level pattern
dominated by broad troughing across much of the CONUS. Our forecast
area resides on the boundary between this troughing and an upper
ridge axis over the FL Peninsula. This ridge axis will suppressed
further south and east over the next 24 hours. Other features of
note include a shortwave impulse embedded within the main flow over
Texas, and a series of weaker impulses working down the backside of
the trough over the inter-mountain west. 12Z KTLH sounding shows a
slowly moistening but still generally stable profile. PW has risen
to over 1.1" this morning, but we continue to see departing
influence of the upper ridge above the surface. Fairly deep layer
between 800-700mb showing an essentially isothermal/stable profile.
This profiles suggests that rain chances will remain near zero
through the afternoon, especially over the eastern half of the
area.
At the surface, subtropical ridge axis extends from off the GA/NE FL
coast westward along the I-10 corridor. To our north and west we
find a quasi-stationary frontal boundary extending across Arkansas
and the Tennessee Valley.
Areas of fog/lower stratus have been rather stubborn over the
eastern half of area this morning, and also over our far western
zones. The lower sun angle this time of year has slowed the process
of mixing this layer out, but should see more and more sunny breaks
developing as we head toward midday.
Through the afternoon, a mix of sun and clouds expected with
temperatures into the upper 70s/low 80s for most locations.
Tonight, shortwave impulse over Texas will shear out as it lifts
northeastward across the lower MS valley. Although this energy will
be de-amplifying, the combination of modest overspreading synoptic
support and a WAA regime should be enough to support widely sct-sct
showers breaking out over the western half of the area. The threat
for a few showers or storms will begin to expand eastward as we
approach sunrise. Southerly flow and increasing moisture will result
in a warm overnight for mid-November. Current grids show low temps
in the mid 60s inland and upper 60s coast. See little reason to make
significant changes at this time.
&&
.AVIATION...
Fog and low CIGS have been very slow to burn off this morning (with
conditions at KTLH actually deteriorating). IFR VSBY should improve
into the afternoon. However, low CIGS at KVLD will be slower to
improve underneath n-s oriented cloud band. Ahead of approaching
cold front, guidance in very good agreement that VSBYS and CIGS will
again begin to further drop after 04Z tonight with MVFR at most
sites and likely remain at IFR/LIFR cigs and possibly VSBYS after
06Z at all sites. Will introduce prob30 for shwrs after midnight at
DHN and TEMPO for DHN/ABY/ECP near sunrise Wed. Near calm winds
will increase to 5 to 10 mph aft 14z with higher gusts especially at
ECP and ABY. Winds will decrease after sunset but remain around 5
mph thru rest of period.
&&
.MARINE...Southeasterly to southerly winds will continue into
Wednesday ahead of the cold front. These winds could briefly
approach cautionary levels on Wednesday afternoon as the frontal
boundary nears the marine area. A period of advisory conditions
appears likely behind the cold front on Thursday. These elevated
winds and seas are expected to persist into Saturday when the
pressure gradient will finally weaken allowing winds to diminish.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 81 66 80 63 76 / 10 20 30 50 10
Panama City 76 68 77 63 73 / 20 30 40 40 0
Dothan 82 65 81 59 71 / 20 40 50 40 0
Albany 83 65 81 60 72 / 10 30 40 40 0
Valdosta 82 65 82 65 75 / 10 10 30 50 10
Cross City 81 64 79 65 78 / 10 10 30 40 20
Apalachicola 75 68 75 66 75 / 10 20 30 40 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
MROCZKA/CAMP
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1250 AM EST TUE NOV 15 2011
.AVIATION...
WK WAVE OF LOW PRESSURE WHICH MOVED ALONG STALLED FRONTAL BOUNDARY
ACROSS NRN INDIANA THIS AFTN HAS MOVED RAPIDLY NE TO NEW ENGLAND TONIGHT.
IN ITS WAKE FRONT HAS SAGGED SOUTH INTO SRN INDIANA BUT GRADIENT
IS VERY WK AS WK RIDGE MOVG INTO THE AREA RESULTING IN LIGHT
SFC WINDS. WITH MOST OF THE AREA RECEIVING SGFNT RAIN OVER THE
PAST 18HRS... RADIATIONAL COOLING HAS ALLOWED PATCHY FOG TO FORM.
VSBYS ACROSS THE AREA CURRENTLY GENERALLY IN THE 2-4SM RANGE WITH
A FEW P6SM... INCLUDING FWA. APPEARS SW FLOW ALOFT WILL MAINTAIN
CIRRUS SHIELD ACROSS THE AREA OVERNIGHT AND GRADIENT APPEARS
SUFFICIENT TO MAINTAIN A LIGHT BREEZE...SO WAS OPTIMISTIC WITH THE
TAFS... MAINTAINING CURRENT MVFR CONDITIONS AT SBN AND VFR AT FWA
THE REST OF THE NIGHT. SW WINDS WILL INCREASE TO 15-25KT THIS AFTN
AS RIDGE MOVES TO THE EAST AND A CDFNT CURRENTLY OVER THE NRN
PLAINS MOVES EAST TO THE UPR GRTLKS. SOME LOW LEVEL MOISTURE
EXPECTED TO BE DRAWN BACK N-NE AHEAD OF THIS CDFNT CAUSING MVFR
CIGS TO MOVE INTO FWA THIS EVE AS FRONT MOVES THROUGH...WHILE JUST
SCT LOW CLOUDS EXPECTED AHEAD OF THE FRONT AT SBN.
&&
PREV DISCUSSION... /ISSUED 425 PM EST MON NOV 14 2011/
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
SEVERE POTENTIAL THROUGH EARLY EVENING WILL BE THE IMMEDIATE SHORT
TERM CONCERN...FOLLOWED BY TRANSITION TO COLDER TEMPERATURES AND
LAKE EFFECT PRECIP POTENTIAL FOR WEDNESDAY/EARLY THURSDAY.
SHORT WAVE FROM THE CENTRAL PLAINS HAS RAPIDLY TRACKED INTO THE
WESTERN GREAT LAKES REGION LATE THIS AFTERNOON. SFC WAVE RIDING
ALONG NORTHWARD MOVING WARM FRONT COMBINED WITH INCREASED
MID/UPPER LEVEL FORCING HAS ALLOWED FOR SOLID LINE OF CONVECTION
TO DEVELOP ALONG A STRONG LOW LEVEL FRONTAL CONVERGENCE ZONE.
EXTREME DEEP LAYER SHEAR NOTED WITH 150 KNOT JET CORE PROGRESSING
THROUGH THE SOUTHERN GREAT LAKES...WITH 0 TO 6 KM DEEP LAYER SHEAR
VALUES ON THE ORDER OF 80 TO 100 KNOTS. A TIGHT INSTABILITY
GRADIENT IS ACCOMPANYING THE WARM FRONT WITH 20Z SPC RUC ANALYSIS
INDICATING BETWEEN 500-700 J/KG OF SFC BASED CAPE ACROSS SOUTHERN
THIRD OF THE FORECAST AREA. THE WARM FRONT HAS LIKELY REACHED ITS
FAR NORTHERN EXTENT BASED ON POSITIONING OF AFOREMENTIONED SURFACE
WAVE. SEVERE POTENTIAL FOR THE REMAINDER OF THE EARLY EVENING
HOURS CAN BE APPROXIMATELY DELINEATED BY CURRENT POSITIONING OF SHARP
FRONTAL CONVERGENCE AXIS. COMBINATION OF SHEAR AND INSTABILITY IS
MORE THAN AMPLE FOR CONTINUED LOW TOP SUPERCELLULAR FEATURES
EMBEDDED ALONG THE LINE...WITH PERIODIC BOWING SEGMENTS GIVEN THE
VERY STRONG FLOW ALOFT. THREAT OF SEVERE SHOULD SHIFT INTO EXTREME
SOUTHEAST AREAS OVER NEXT HOUR OR TWO...BEFORE EXITING THE
FORECAST AREA TOWARD 00Z.
COLD ADVECTION BEHIND SURFACE WAVE TONIGHT IS NOT EXPECTED TO BE
PARTICULARLY STRONG DUE TO MAINTENANCE OF LONG WAVE TROUGHING
ACROSS MUCH OF CENTRAL CONUS. APPROACH OF NEXT SFC TROUGH FROM THE
CENTRAL/NORTHERN PLAINS WILL ALLOW LOW LEVEL WINDS TO BACK AGAIN
LATE TONIGHT AND ON TUESDAY...WITH STRONG WARM ADVECTION
DEVELOPING ONCE AGAIN DURING THE DAY. SOME LIMITED LOW LEVEL
MOISTURE RETURN IS POSSIBLE IN ADVANCE OF THIS WAVE TUESDAY NIGHT
ACROSS MAINLY FAR SOUTHEAST PORTIONS OF THE AREA. IN
ADDITION...APPROACHING LARGER SCALE UPPER TROUGH MAY ACT TO
ENHANCE SOME WEAK TO MODERATE MID LEVEL FRONTOGENESIS. GIVEN THESE
FACTORS...DID ADD SLIGHT CHANCE OF SHOWERS ACROSS EXTREME
SOUTHEAST TUESDAY NIGHT...WITH GREATER CHANCES OF SHOWERS
REMAINING SOUTHEAST OF THE AREA. TEMPERATURES BACK INTO THE UPPER
50S TO AROUND 60 EXPECTED ON TUESDAY AFTERNOON WITH JUST SOME
PASSING MID CLOUDS EXPECTED.
LONG TERM...WEDNESDAY THROUGH MONDAY
FRONTAL PASSAGE LATE TUESDAY NIGHT WILL ALLOW FOR STRONG LOW LEVEL
COLD ADVECTION ON WEDNESDAY. MODIFIED GFS BUFFER SOUNDINGS FOR
SOUTHERN LAKE MICHIGAN CONDITIONS SUGGEST SUFFICIENT LAKE INDUCED
INSTABILITY FOR SCT SNOW SHOWER/FLURRY CHANCES. WILL KEEP PRECIP
TYPE AS SNOW SHOWERS FOR MAINLY EXTREME SOUTHWESTERN LOWER
MICHIGAN DUE TO A FAIRLY DRY SUBCLOUD LAYER. WILL MAINTAIN SLIGHT
CHANCE OF SHOWERS FURTHER INLAND ON WEDNESDAY EVENING ACROSS MUCH
OF SOUTHERN LOWER MICHIGAN AS MAIN UPPER TROUGH AXIS MOVES ACROSS
THE GREAT LAKES. THE THERMAL ROLLER COASTER RIDE WILL CONTINUE BY
THE END OF THE WEEK AS A STRONG SOUTHWESTERLY LOW LEVEL JET WILL
BRING LOW LEVEL THERMAL RIDGING BACK INTO THE REGION AND A
MODERATING TEMPERATURE TREND. THE NEXT STRONG EASTERN PACIFIC JET
WILL DIG INTO WESTERN CONUS FRIDAY ALLOWING FOR LONGWAVE
AMPLIFICATION...WHICH WILL EVENTUALLY SUPPORT RAIN SHOWER CHANCES
FOR MUCH OF NEXT WEEKEND AS THIS TROUGH LIFTS ACROSS NORTHERN TIER
OF CONUS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 10 PM EST
WEDNESDAY FOR LMZ043-046.
&&
$$
SHORT TERM...MARSILI
LONG TERM...MARSILI
AVIATION...JT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
354 PM MST TUE NOV 15 2011
.SHORT TERM (TONIGHT)...
239 PM MST TUE NOV 15 2011
18Z WATER VAPOR IMAGERY DEPICTS CONTINUED BROAD UPPER LEVEL TROUGH
ACROSS NORTHERN CONUS MUCH LIKE YESTERDAY WITH FORECAST AREA WITH
GENERAL ZONAL FLOW NEAR THE SOUTHERN EXTENT OF WEAKLY DEFINED
TROUGH AXIS. EMBEDDED IN THE MEAN FLOW IS A SHORTWAVE TROUGH MOVING
ACROSS THE SOUTHWEST WYOMING AREA. AT THE SURFACE A COLD FRONT SOUTH
OF THE AREA PRODUCED BREEZY POST-FRONTAL WINDS MOST NOTABLY ACROSS
FAR NW KANSAS. PRIMARY FORECAST CONCERN THIS EVENING AND OVERNIGHT
WILL BE SNOW CHANCES AND AMOUNTS.
SHORT-RANGE NWP IN GOOD GENERAL AGREEMENT ON LARGE SCALE FEATURES
BUT ARE QUITE DIFFERENT IN HANDLING OF DETAILS AND SUBSEQUENT PRECIP
OUTPUT. LOW LEVEL MOISTURE IS STILL SOMEWHAT OF A CONCERN BUT SEEMS
MUCH MORE PLENTIFUL WITH LATEST OPS GUIDANCE AND WILL WARRANT AN
INCREASE IN POPS OVERNIGHT FROM FLURRIES...ALONG WITH SNOW AMOUNTS.
THE LONGWAVE TROUGH WILL GENERALLY AMPLIFY THROUGH THE PERIOD WITH
THE APPROACHING SHORTWAVE TROUGH. THE FORECAST AREA WILL BE UNDER
THE INFLUENCE OF AN EXITING JET STREAK TO THE NORTHEAST AND AN
APPROACHING JET STREAK MOVING AROUND THE WEST SIDE OF TROUGH AXIS.
LARGE SCALE FORCING FOR ASCENT WILL MOVE OVER THE AREA THIS EVENING
AND WILL BE MAXIMIZED BETWEEN 06Z-12Z. IN ADDITION...MODELS IN
DECENT AGREEMENT WITH H7-H6 FRONTO-G FIELD ACROSS NORTHWEST KANSAS
ROUGHLY ALONG AND NORTH OF INTERSTATE 70 AROUND 06Z...SHIFTING
E/SE-WARD OVERNIGHT. THERE IS A CONCERN FOR THE POTENTIAL FOR SOME
BANDING TO OCCUR...PARTICULARLY IN ROUGHLY THE SAME REGION AS
MENTIONED ABOVE WITH REGARD TO FRONTO-G...GIVEN LOW TO NEGATIVE EPV
VALUES COUPLED WITH THETA-E LAPSE RATES AROUND 1-2C IN THAT AREA.
DESPITE THIS...THE FORWARD SPEED OF THE SHORTWAVE TROUGH IN MEAN
NORTHWEST FLOW HOWEVER WOULD CERTAINLY SEEM A LIMITATION TO QPF
AMOUNTS. IN ADDITION...THOUGH LOW LEVEL SATURATION DOES LOOK BETTER
THAN PREVIOUS MODEL RUNS...MOISTURE ADVECTION INTO THE FORECAST AREA
IS GENERALLY WEAK AT BEST THOUGH IT LOOKS JUST A BIT BETTER AROUND
H7. GIVEN THIS...WILL STILL LIMIT TOTAL SNOW AMOUNTS TO GENERALLY
AROUND A HALF INCH. -050
.LONG TERM (WEDNESDAY-TUESDAY)...
239 PM MST TUE NOV 15 2011
THE UPPER TROUGH WILL BE MOVING ACROSS THE CENTRAL PLAINS WEDNESDAY
MORNING FOLLOWED BY NORTHWEST FLOW WEDNESDAY NIGHT/THURSDAY. FLOW
BECOMES ZONAL THURSDAY NIGHT/FRIDAY TRANSITIONING TO SOUTHWEST FLOW
FRIDAY NIGHT. SURFACE HIGH PRESSURE WILL CONTINUE OVER THE CENTRAL
PLAINS WEDNESDAY/WEDNESDAY NIGHT. AS THE HIGH SHIFTS EAST THURSDAY,
A TROUGH WILL MOVE INTO EASTERN COLORADO AND REMAIN THROUGH FRIDAY
NIGHT.
FORCING IS INDICATED OVER THE FA WEDNESDAY MORNING AS THE UPPER
TROUGH MOVES THROUGH. FORECAST SOUNDINGS INDICATE THAT MOISTURE
DECREASES SHORTLY AFTER 12Z ACROSS MOST AREAS EXCEPT THE FAR EAST
ZONES. INCREASED POPS TO SLIGHT CHANCE OVER THE KANSAS/NEBRASKA
ZONES WEDNESDAY MORNING WITH A SMALL AREA OF CHANCE POPS NEAR HILL
CITY. OTHERWISE SCATTERED FLURRIES ARE OVER PORTIONS OF EASTERN
COLORADO AND A SMALL PORTION OF THE SOUTHERN ZONES. SUBSIDENCE MOVES
INTO THE FA BEHIND THE EXITING TROUGH WEDNESDAY AFTERNOON.
SUBSIDENCE WILL CONTINUE THURSDAY AND FOR REMAINING PERIODS THROUGH
FRIDAY NIGHT. CONSEQUENTLY POPS WILL BE NIL.
MIN TEMPERATURES WILL RANGE FROM THE LOWER 20S WEDNESDAY NIGHT
WARMING TO THE LOW/MID 30S THURSDAY/FRIDAY NIGHTS. MAX TEMPERATURES
WILL BE IN THE 30S TO AROUND 40 WEDNESDAY. ASSUMING ANY SNOW THAT
FALLS WILL MELT QUICKLY, HIGH TEMPERATURES THURSDAY AND FRIDAY WILL
RISE INTO THE MID/UPPER 50S.
IN THE EXTENDED...THERE ARE SOME DIFFERENCES WITH THE GFS AND THE
ECMWF FOR THE SATURDAY PERIOD. THE GFS BRUSHES THE FAR NORTHWEST
PORTION OF THE FA WITH DYNAMICS WHILE THE ECMWF KEEPS SUBSIDENCE
OVER THAT AREA WITH DYNAMICS WELL NORTH. FOR NOW WILL OPT FOR THE
ECMWF SOLUTION WITH NIL POPS. SOUTHWEST FLOW CONTINUES FOR THE
PERIODS SUNDAY THROUGH TUESDAY. SUBSIDENCE IS INDICATED DURING THESE
PERIODS SO WILL KEEP POPS NIL. THE GFS/ECMWF BRING AN UPPER LOW EAST
INTO NEW MEXICO MONDAY NIGHT AND THEN ACROSS THE TEXAS/OKLAHOMA
PANHANDLE REGION TUESDAY/TUESDAY NIGHT. PLAN TO GO WITH SLIGHT
CHANCE POPS ACROSS THE SOUTHERN ZONES MONDAY NIGHT. CHANCE POPS LOOK
ON TRACK FOR THE ENTIRE FA TUESDAY/TUESDAY NIGHT.
MAX TEMPERATURES SATURDAY SHOULD BE NORMAL WITH READINGS IN THE
LOWER TO MID 50S. COOLER TEMPERATURES IN THE MID 40S SHOULD OCCUR
BEHIND THE FRONT SUNDAY. MAX TEMPERATURES WILL WARM INTO THE UPPER
40S MONDAY AND THEN COOL TO THE MID 40S TUESDAY. MIN TEMPERATURES
WILL GENERALLY BE NORMAL IN THE MID 20S WITH SOME TEMPERATURES NEAR
30 TUESDAY NIGHT.
FS
&&
.AVIATION...
354 PM MST TUE NOV 15 2011
FOR THE 00Z TAFS...A FAST-MOVING DISTURBANCE WILL BRING A CHANCE
OF SNOW TO THE TERMINALS THIS EVENING...WHICH IS EXPECTED TO
DECREASE CONDITIONS BELOW VFR BEFORE MOVING EAST OF THE TERMINALS.
CONSIDERING MODEL SOUNDINGS FOR TOMORROW MORING...THERE IS
CONSIDERABLE UNCERTAINTY AS TO HOW LOW THE CEILINGS WILL GET...BUT
THERE IS ENOUGH AGREEMENT TO INCLUDE MVFR CONDITIONS AT EACH
TERMINAL. BASED ON HOW THE NAM AND HRRR ARE HANDLING THE
EVENT...HAVE INCLUDED IFR CEILINGS AT KMCK AS THEY RECEIVE
SNOWFALL. AS THE DISTURBANCE MOVES EASTWARD...CONDITIONS ARE
EXPECTED TO RETURN TO VFR BY LATE MORNING AT KGLD AND EARLY
AFTERNOON AT KMCK.
CJS
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1108 AM CST TUE NOV 15 2011
.UPDATE...NO MAJOR CHANGES IN THE FORECAST THINKING. DISTURBANCE
HAS NOW MOVED INTO TX WITH CONVECTION OCCURRING ACROSS SRN/SERN
TX. WEAK SFC WAVE IS OVER CNTRL TX AND THIS IS LEADING TO DEEP
SRLY/SERLY FLOW. LATEST RUC IS INDICATING AN AREA OF MUCH LOWER
H85 THETA E AIR MOVING IN FROM THE GULF AND THIS WILL LIKELY HURT
CONVECTION FOR A WHILE TODAY. WITH THAT WE HAVE BACKED OFF ON THE
POPS AND WILL JUST MENTION SCT SHRA THROUGH THE REMAINDER OF THE
DAY. IN ADDITION HAVE LOWERED HIGHS ACROSS SWRN MS A FEW DEGREES.
THE STRONG/SVR ASPECT LOOKS TO BE MORE THIS EVN SO WILL DO A
MORE THOROUGH UPDATE ON THAT THIS AFTN. QUICKLY THOUGH THE LATEST
MDLS ARE TRYING TO HOLD ONTO THE S/W A LITTLE LONGER AND HAVE IT A
TAD FURTHER SOUTH. THIS LOOKS LIKE IT WILL LEAD TO SLIGHTLY BETTER
INSTABILITY AND COMBINE THAT WITH DECENT FORCING AND ONGOING
CONVECTION IN SERN TX/ AND SWRN/WRN LA THERE IS STILL A CHANCE OF
SEEING A FEW STRONG TO SVR STORMS...MAINLY ACROSS NWRN PORTIONS OF
THE CWA.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 78 65 76 44 / 50 70 40 10
BTR 81 66 80 48 / 50 70 20 10
ASD 80 67 82 51 / 50 50 40 10
MSY 81 67 82 54 / 50 50 30 10
GPT 78 67 82 51 / 50 50 50 20
PQL 79 65 81 51 / 50 50 50 30
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
CAB
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1222 PM EST TUE NOV 15 2011
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA EARLY TODAY. HIGH
PRESSURE WILL BUILD BRIEFLY ACROSS THE REGION TONIGHT. ANOTHER LOW
PRESSURE SYSTEM WILL MOVE OFF THE MID ATLANTIC COAST AND MOVE TOWARD
THE SOUTHERN GULF OF MAINE ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE 3: AS ALLUDED IN THE PRIOR DISC...CLDNSS HAS NOT GIVEN WAY
MUCH...SO WE HAD TO INCREASE CLD CVR FOR OUR FA THIS AFTN...AND
DELAY CLRG FOR THIS EVE. THIS GREATER CLD CVR HAS SOMEWHAT
IMPACTED ON MIXING POTENTIAL WITH STRONGER WINDS ALF AND MAX
POTENTIAL HTG...SO WE LOWERED WIND SPEEDS AND HI TEMPS SLGTLY.
UPDATE 2: NOT MANY CHGS FROM PREV FCST ATTM...WITH RADAR INDICATING
THE BACK EDGE OF SHWRS ABOUT READY TO EXIT INTO NB PROV. ONE
CONCERN IS HOW MUCH SUNSHINE THE FA WILL RECEIVE THIS AFTN WITH
THE CURRENT FCST OF BECOMING MSLY SUNNY SOMEWHAT IN JEOPARDY WITH
THE BACK EDGE OF A BAND OF HI/MID CLDS NOT MOVG VERY QUICKLY EWRD
FROM THE ST LAWRENCE RVR...DESPITE THE EROSION OF LOW CLDS XPCTD
BY AFTN WITHE DRIER AIR ARRIVING BEHIND THE WEAK COLD FRONT
CURRENTLY CLRG THE FA. WILL HOLD ON FOR NOW...BUT MAY NEED TO MAKE
ADJUSTMENTS FOR THE MIDDAY UPDATE. OTHERWISE...WE INCORPORATED
LATEST HRLY SFC TEMPS AND MADE MINOR ADJUSTMENTS TO FCST AFTN HI
TEMPS.
UPDATE 1: ADJUSTED THE POPS FURTHER EAST W/THE HIGHEST POPS IN NEW
BRUNSWICK. TEMPERATURES WERE TWEAKED TO MATCH CURRENT CONDITIONS.
06-12Z QPF WAS ADJUSTED DOWNWARD FROM THE PREVIOUS PACKAGE BASED
ON THE LATEST REPORTS.
ORGNL DISC: LATEST RADAR LOOP SHOWED 2 AREAS OF RAIN MOVING ACROSS THE
REGION W/ONE AREA ACROSS NORTHERN MAINE AND THE OTHER AREA MOVING
ACROSS DOWNEAST AND EASTERN AREAS. WEAK AREA OF LOW PRES IS
PASSING ACROSS THE ST.LAWRENCE RIVER ATTM W/ITS ASSOCIATED COLD
FRONT PUSHING TOWARD WESTERN MAINE. A BLEND OF THE RUC AND NAM WAS
USED THROUGH LATE THIS MORNING W/TAKING SHOWER INTO NEW BRUNSWICK
BY 15Z. THIS MATCHES UP WELL W/THE MID LEVEL FORCING EXITING THE
REGION BY 15Z AS IT LINES UP WELL W/THE RADAR ATTM. QPF FROM THIS
EVENT WILL BE AROUND .10-.15" AT BEST. MDL SOUNDINGS AND BUFKIT
PROFILES INDICATE THAT AIRMASS WILL DRY OUT ABOVE 850MBS ALLOWING
FOR MORE SUNSHINE. WSW WIND WILL TAKE HOLD LATER THIS MORNING INTO
THE AFTERNOON AS THE COLD FRONT SWINGS ACROSS THE REGION. THE NAM
HAS BACKED DOWN FROM ITS PREVIOUS FCSTS OF SHOWING SOME STRONGER
WINDS MIXING DOWN FROM 5K FT. THEREFORE...CUT BACK WIND GUSTS
TODAY TO AROUND 25 MPH ACROSS THE NORTHERN 1/2 OF THE CWA AS BOTH
THE GFS AND NAM SHOW LESS MIXING THIS AFTERNOON. WEAK CAA THROUGH
THE COLUMN TO TAKE HOLD THIS AFTERNOON AND W/A WESTERLY WIND IN
PLACE. THINKING HERE IS THAT TEMPERATURES WILL NOT BE AS WARM AS
MET GUIDANCE IS SHOWING W/MID TO UPPER 50S ACROSS THE NORTH AND
AROUND 60 FOR THE CENTRAL HIGHLANDS AND DOWNEAST AREAS. A BLEND OF
THE MAV AND LAMP GUIDANCE WAS USED FOR TEMPERATURES WHICH SHOWS
UPPER 40S TO LOWER 50S ACROSS THE NORTH AND MID TO UPPER 50S FOR
THE CENTRAL HIGHLANDS AND DOWNEAST.
FOR TONIGHT...CLOUDS WILL GIVE WAY TO MOSTLY CLEAR SKIES AS HIGH
PRES RIDGES ACROSS THE CWA. THIS WILL BE SHORT-LIVED AS CLOUDS
FROM THE NEXT SYSTEM WILL BE MOVING INTO THE REGION FROM THE WSW
LATER TONIGHT. THIS WILL KEEP TEMPERATURES FROM FALLING BACK TOO
LOW. ONCE AGAIN, FOLLOWED THE GMOS AND LAMP GUIDANCE FOR THE MINS
WHICH SHOWED MID-UPPER 30S ACROSS THE NORTH AND CENTRAL AREAS
WHILE LOWER 40S WILL DO FOR THE DOWNEAST REGION.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
LOW PRESSURE WILL TRACK TO OUR NORTH DURING WEDNESDAY...AS ANOTHER
WEAK DISTURBANCE TRACKS NORTHEAST OF THE SOUTHERN NEW ENGLAND
COAST. THIS WILL BRING INCREASING CLOUDS ACROSS THE REGION ON
WEDNESDAY BUT LITTLE IF ANY PRECIPITATION...AS MOST OF THE MOISTURE
ASSOCIATED WITH THE NORTHERN LOW REMAINS ACROSS QUEBEC...AND
MOISTURE WITH THE SOUTHERN SYSTEM REMAINS TO OUR SOUTH. WINDS
WILL BECOME MORE WESTERLY WEDNESDAY NIGHT WITH PARTLY CLOUDY SKIES
AND DRY WEATHER EXPECTED. AN UPPER LEVEL TROUGH WILL APPROACH FROM
THE WEST DURING THURSDAY. ANOTHER WEAK DISTURBANCE WILL MOVE
NORTHEAST FROM THE SOUTHERN NEW ENGLAND COAST DURING THE DAY
THURSDAY. ALTHOUGH MUCH OF THE MOISTURE ASSOCIATED WITH THIS
SYSTEM WILL REMAIN TO OUR SOUTH SOME LIGHT SHOWERS MAY REACH THE
DOWNEAST COAST LATER THURSDAY AS THE LOW TRACKS NORTHEAST.
HIGHS ON WEDNESDAY WILL BE ABOVE NORMAL...THEN BE NEAR NORMAL ON
THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE UPPER LEVEL TROUGH WILL MOVE EAST THURSDAY NIGHT WITH HIGH
PRESSURE BUILDING EAST ON FRIDAY. THE HIGH WILL MOVE EAST FRIDAY
NIGHT AND SATURDAY. A WARM FRONT WILL APPROACH SATURDAY NIGHT AND
LIFT NORTHEAST EARLY SUNDAY...FOLLOWED BY A COLD FRONT LATER SUNDAY
AFTERNOON. HIGH PRESSURE WILL BUILD EAST ON MONDAY.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: IFR/MVFR EARLY TODAY WILL GIVE WAY TO VFR BY LATE
MORNING INTO TONIGHT.
SHORT TERM: MAINLY VFR THROUGH THE PERIOD.
&&
.MARINE...
NEAR TERM: WE WILL KEEP STATUS QUO ON CURRENT SCA FOR NOW. PLAN
ON DROPPING SCA FOR INNER HARBOR MZ052 AND TRANSFORMING THE SCA
TO SCA FOR HAZ SEAS FOR OUTER MZS 050-051 FOR THE NEXT AFTN
UPDATE.
SHORT TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS WEDNESDAY AND
TROUGH THURSDAY AND THEN POSSIBLY INCREASE TO SCA LEVELS THURSDAY
NIGHT THROUGH SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...VJN
MARINE...VJN/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
930 AM EST TUE NOV 15 2011
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA EARLY TODAY. HIGH
PRESSURE WILL BUILD BRIEFLY ACROSS THE REGION TONIGHT. ANOTHER LOW
PRESSURE SYSTEM WILL MOVE OFF THE MID ATLANTIC COAST AND MOVE TOWARD
THE SOUTHERN GULF OF MAINE ON WEDNESDAY.&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE 2: NOT MANY CHGS FROM PREV FCST ATTM...WITH RADAR INDICATING
THE BACK EDGE OF SHWRS ABOUT READY TO EXIT INTO NB PROV. ONE
CONCERN IS HOW MUCH SUNSHINE THE FA WILL RECEIVE THIS AFTN WITH
THE CURRENT FCST OF BECOMING MSLY SUNNY SOMEWHAT IN JEOPARDY WITH
THE BACK EDGE OF A BAND OF HI/MID CLDS NOT MOVG VERY QUICKLY EWRD
FROM THE ST LAWRENCE RVR...DESPITE THE EROSION OF LOW CLDS XPCTD
BY AFTN WITHE DRIER AIR ARRIVING BEHIND THE WEAK COLD FRONT
CURRENTLY CLRG THE FA. WILL HOLD ON FOR NOW...BUT MAY NEED TO MAKE
ADJUSTMENTS FOR THE MIDDAY UPDATE. OTHERWISE...WE INCORPORATED
LATEST HRLY SFC TEMPS AND MADE MINOR ADJUSTMENTS TO FCST AFTN HI
TEMPS.
UPDATE 1: ADJUSTED THE POPS FURTHER EAST W/THE HIGHEST POPS IN NEW
BRUNSWICK. TEMPERATURES WERE TWEAKED TO MATCH CURRENT CONDITIONS.
06-12Z QPF WAS ADJUSTED DOWNWARD FROM THE PREVIOUS PACKAGE BASED
ON THE LATEST REPORTS.
ORGNL DISC: LATEST RADAR LOOP SHOWED 2 AREAS OF RAIN MOVING ACROSS THE
REGION W/ONE AREA ACROSS NORTHERN MAINE AND THE OTHER AREA MOVING
ACROSS DOWNEAST AND EASTERN AREAS. WEAK AREA OF LOW PRES IS
PASSING ACROSS THE ST.LAWRENCE RIVER ATTM W/ITS ASSOCIATED COLD
FRONT PUSHING TOWARD WESTERN MAINE. A BLEND OF THE RUC AND NAM WAS
USED THROUGH LATE THIS MORNING W/TAKING SHOWER INTO NEW BRUNSWICK
BY 15Z. THIS MATCHES UP WELL W/THE MID LEVEL FORCING EXITING THE
REGION BY 15Z AS IT LINES UP WELL W/THE RADAR ATTM. QPF FROM THIS
EVENT WILL BE AROUND .10-.15" AT BEST. MDL SOUNDINGS AND BUFKIT
PROFILES INDICATE THAT AIRMASS WILL DRY OUT ABOVE 850MBS ALLOWING
FOR MORE SUNSHINE. WSW WIND WILL TAKE HOLD LATER THIS MORNING INTO
THE AFTERNOON AS THE COLD FRONT SWINGS ACROSS THE REGION. THE NAM
HAS BACKED DOWN FROM ITS PREVIOUS FCSTS OF SHOWING SOME STRONGER
WINDS MIXING DOWN FROM 5K FT. THEREFORE...CUT BACK WIND GUSTS
TODAY TO AROUND 25 MPH ACROSS THE NORTHERN 1/2 OF THE CWA AS BOTH
THE GFS AND NAM SHOW LESS MIXING THIS AFTERNOON. WEAK CAA THROUGH
THE COLUMN TO TAKE HOLD THIS AFTERNOON AND W/A WESTERLY WIND IN
PLACE. THINKING HERE IS THAT TEMPERATURES WILL NOT BE AS WARM AS
MET GUIDANCE IS SHOWING W/MID TO UPPER 50S ACROSS THE NORTH AND
AROUND 60 FOR THE CENTRAL HIGHLANDS AND DOWNEAST AREAS. A BLEND OF
THE MAV AND LAMP GUIDANCE WAS USED FOR TEMPERATURES WHICH SHOWS
UPPER 40S TO LOWER 50S ACROSS THE NORTH AND MID TO UPPER 50S FOR
THE CENTRAL HIGHLANDS AND DOWNEAST.
FOR TONIGHT...CLOUDS WILL GIVE WAY TO MOSTLY CLEAR SKIES AS HIGH
PRES RIDGES ACROSS THE CWA. THIS WILL BE SHORT-LIVED AS CLOUDS
FROM THE NEXT SYSTEM WILL BE MOVING INTO THE REGION FROM THE WSW
LATER TONIGHT. THIS WILL KEEP TEMPERATURES FROM FALLING BACK TOO
LOW. ONCE AGAIN, FOLLOWED THE GMOS AND LAMP GUIDANCE FOR THE MINS
WHICH SHOWED MID-UPPER 30S ACROSS THE NORTH AND CENTRAL AREAS
WHILE LOWER 40S WILL DO FOR THE DOWNEAST REGION.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
LOW PRESSURE WILL TRACK TO OUR NORTH DURING WEDNESDAY...AS ANOTHER
WEAK DISTURBANCE TRACKS NORTHEAST OF THE SOUTHERN NEW ENGLAND
COAST. THIS WILL BRING INCREASING CLOUDS ACROSS THE REGION ON
WEDNESDAY BUT LITTLE IF ANY PRECIPITATION...AS MOST OF THE MOISTURE
ASSOCIATED WITH THE NORTHERN LOW REMAINS ACROSS QUEBEC...AND
MOISTURE WITH THE SOUTHERN SYSTEM REMAINS TO OUR SOUTH. WINDS
WILL BECOME MORE WESTERLY WEDNESDAY NIGHT WITH PARTLY CLOUDY SKIES
AND DRY WEATHER EXPECTED. AN UPPER LEVEL TROUGH WILL APPROACH FROM
THE WEST DURING THURSDAY. ANOTHER WEAK DISTURBANCE WILL MOVE
NORTHEAST FROM THE SOUTHERN NEW ENGLAND COAST DURING THE DAY
THURSDAY. ALTHOUGH MUCH OF THE MOISTURE ASSOCIATED WITH THIS
SYSTEM WILL REMAIN TO OUR SOUTH SOME LIGHT SHOWERS MAY REACH THE
DOWNEAST COAST LATER THURSDAY AS THE LOW TRACKS NORTHEAST.
HIGHS ON WEDNESDAY WILL BE ABOVE NORMAL...THEN BE NEAR NORMAL ON
THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE UPPER LEVEL TROUGH WILL MOVE EAST THURSDAY NIGHT WITH HIGH
PRESSURE BUILDING EAST ON FRIDAY. THE HIGH WILL MOVE EAST FRIDAY
NIGHT AND SATURDAY. A WARM FRONT WILL APPROACH SATURDAY NIGHT AND
LIFT NORTHEAST EARLY SUNDAY...FOLLOWED BY A COLD FRONT LATER SUNDAY
AFTERNOON. HIGH PRESSURE WILL BUILD EAST ON MONDAY.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: IFR/MVFR EARLY TODAY WILL GIVE WAY TO VFR BY LATE
MORNING INTO TONIGHT.
SHORT TERM: MAINLY VFR THROUGH THE PERIOD.
&&
.MARINE...
NEAR TERM: SCA WILL REMAIN IN PLACE FOR BOTH WINDS AND SEAS W/THE
SCA MOST LIKELY BE TRANSITIONED TO HAZARDOUS SEAS BY LATER TODAY
INTO EARLY TONIGHT AS A SWELL HANGS ON. USED A NAM12/GFS BLEND FOR
THE WINDS W/KEEPS GUSTS TO 25 KTS EARLY AND THEN WINDS DIMINISH
W/HIGH PRES SETTLING IN. ADJUSTED THE SEAS DOWN BY A FOOT AS THE
LATEST OBS ARE RUNNING A FOOT TOO LOW THAN FCST.
SHORT TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS WEDNESDAY AND
TROUGH THURSDAY AND THEN POSSIBLY INCREASE TO SCA LEVELS THURSDAY
NIGHT THROUGH SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...VJN
MARINE...VJN/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
634 AM EST TUE NOV 15 2011
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA EARLY TODAY. HIGH
PRESSURE WILL BUILD BRIEFLY ACROSS THE REGION TONIGHT. ANOTHER LOW
PRESSURE SYSTEM WILL MOVE OFF THE MID ATLANTIC COAST AND MOVE TOWARD
THE SOUTHERN GULF OF MAINE ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
.UPDATE...
ADJUSTED THE POPS FURTHER EAST W/THE HIGHEST POPS IN
NEW BRUNSWICK. TEMPERATURES WERE TWEAKED TO MATCH CURRENT
CONDITIONS. 06-12Z QPF WAS ADJUSTED DOWNWARD FROM THE PREVIOUS
PACKAGE BASED ON THE LATEST REPORTS.
.PREVIOUS DISCUSSION...
LATEST RADAR LOOP SHOWED 2 AREAS OF RAIN MOVING ACROSS THE REGION
W/ONE AREA ACROSS NORTHERN MAINE AND THE OTHER AREA MOVING ACROSS
DOWNEAST AND EASTERN AREAS. WEAK AREA OF LOW PRES IS PASSING
ACROSS THE ST.LAWRENCE RIVER ATTM W/ITS ASSOCIATED COLD FRONT
PUSHING TOWARD WESTERN MAINE. A BLEND OF THE RUC AND NAM WAS USED
THROUGH LATE THIS MORNING W/TAKING SHOWER INTO NEW BRUNSWICK BY
15Z. THIS MATCHES UP WELL W/THE MID LEVEL FORCING EXITING THE
REGION BY 15Z AS IT LINES UP WELL W/THE RADAR ATTM. QPF FROM THIS
EVENT WILL BE AROUND .10-.15" AT BEST. MDL SOUNDINGS AND BUFKIT
PROFILES INDICATE THAT AIRMASS WILL DRY OUT ABOVE 850MBS ALLOWING
FOR MORE SUNSHINE. WSW WIND WILL TAKE HOLD LATER THIS MORNING INTO
THE AFTERNOON AS THE COLD FRONT SWINGS ACROSS THE REGION. THE NAM
HAS BACKED DOWN FROM ITS PREVIOUS FCSTS OF SHOWING SOME STRONGER
WINDS MIXING DOWN FROM 5K FT. THEREFORE...CUT BACK WIND GUSTS
TODAY TO AROUND 25 MPH ACROSS THE NORTHERN 1/2 OF THE CWA AS BOTH
THE GFS AND NAM SHOW LESS MIXING THIS AFTERNOON. WEAK CAA THROUGH
THE COLUMN TO TAKE HOLD THIS AFTERNOON AND W/A WESTERLY WIND IN
PLACE. THINKING HERE IS THAT TEMPERATURES WILL NOT BE AS WARM AS
MET GUIDANCE IS SHOWING W/MID TO UPPER 50S ACROSS THE NORTH AND
AROUND 60 FOR THE CENTRAL HIGHLANDS AND DOWNEAST AREAS. A BLEND OF
THE MAV AND LAMP GUIDANCE WAS USED FOR TEMPERATURES WHICH SHOWS
UPPER 40S TO LOWER 50S ACROSS THE NORTH AND MID TO UPPER 50S FOR
THE CENTRAL HIGHLANDS AND DOWNEAST.
FOR TONIGHT...CLOUDS WILL GIVE WAY TO MOSTLY CLEAR SKIES AS HIGH
PRES RIDGES ACROSS THE CWA. THIS WILL BE SHORT-LIVED AS CLOUDS
FROM THE NEXT SYSTEM WILL BE MOVING INTO THE REGION FROM THE WSW
LATER TONIGHT. THIS WILL KEEP TEMPERATURES FROM FALLING BACK TOO
LOW. ONCE AGAIN, FOLLOWED THE GMOS AND LAMP GUIDANCE FOR THE MINS
WHICH SHOWED MID-UPPER 30S ACROSS THE NORTH AND CENTRAL AREAS
WHILE LOWER 40S WILL DO FOR THE DOWNEAST REGION.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
LOW PRESSURE WILL TRACK TO OUR NORTH DURING WEDNESDAY...AS ANOTHER
WEAK DISTURBANCE TRACKS NORTHEAST OF THE SOUTHERN NEW ENGLAND
COAST. THIS WILL BRING INCREASING CLOUDS ACROSS THE REGION ON
WEDNESDAY BUT LITTLE IF ANY PRECIPITATION...AS MOST OF THE MOISTURE
ASSOCIATED WITH THE NORTHERN LOW REMAINS ACROSS QUEBEC...AND
MOISTURE WITH THE SOUTHERN SYSTEM REMAINS TO OUR SOUTH. WINDS
WILL BECOME MORE WESTERLY WEDNESDAY NIGHT WITH PARTLY CLOUDY SKIES
AND DRY WEATHER EXPECTED. AN UPPER LEVEL TROUGH WILL APPROACH FROM
THE WEST DURING THURSDAY. ANOTHER WEAK DISTURBANCE WILL MOVE
NORTHEAST FROM THE SOUTHERN NEW ENGLAND COAST DURING THE DAY
THURSDAY. ALTHOUGH MUCH OF THE MOISTURE ASSOCIATED WITH THIS
SYSTEM WILL REMAIN TO OUR SOUTH SOME LIGHT SHOWERS MAY REACH THE
DOWNEAST COAST LATER THURSDAY AS THE LOW TRACKS NORTHEAST.
HIGHS ON WEDNESDAY WILL BE ABOVE NORMAL...THEN BE NEAR NORMAL ON
THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE UPPER LEVEL TROUGH WILL MOVE EAST THURSDAY NIGHT WITH HIGH
PRESSURE BUILDING EAST ON FRIDAY. THE HIGH WILL MOVE EAST FRIDAY
NIGHT AND SATURDAY. A WARM FRONT WILL APPROACH SATURDAY NIGHT AND
LIFT NORTHEAST EARLY SUNDAY...FOLLOWED BY A COLD FRONT LATER SUNDAY
AFTERNOON. HIGH PRESSURE WILL BUILD EAST ON MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: IFR/MVFR EARLY TODAY WILL GIVE WAY TO VFR BY LATE
MORNING INTO TONIGHT.
SHORT TERM: MAINLY VFR THROUGH THE PERIOD.
&&
.MARINE...
NEAR TERM: SCA WILL REMAIN IN PLACE FOR BOTH WINDS AND SEAS W/THE
SCA MOST LIKELY BE TRANSITIONED TO HAZARDOUS SEAS BY LATER TODAY
INTO EARLY TONIGHT AS A SWELL HANGS ON. USED A NAM12/GFS BLEND FOR
THE WINDS W/KEEPS GUSTS TO 25 KTS EARLY AND THEN WINDS DIMINISH
W/HIGH PRES SETTLING IN. ADJUSTED THE SEAS DOWN BY A FOOT AS THE
LATEST OBS ARE RUNNING A FOOT TOO LOW THAN FCST.
SHORT TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS WEDNESDAY AND
TROUGH THURSDAY AND THEN POSSIBLY INCREASE TO SCA LEVELS THURSDAY
NIGHT THROUGH SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
416 AM EST TUE NOV 15 2011
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA EARLY TODAY. HIGH
PRESSURE WILL BUILD BRIEFLY ACROSS THE REGION TONIGHT. ANOTHER LOW
PRESSURE SYSTEM WILL MOVE OFF THE MID ATLANTIC COAST AND MOVE TOWARD
THE SOUTHERN GULF OF MAINE ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE BIGGEST CHALLENGE THIS TERM WILL BE THE SHOWERS AND TEMPERATURES.
LATEST RADAR LOOP SHOWED 2 AREAS OF RAIN MOVING ACROSS THE REGION
W/ONE AREA ACROSS NORTHERN MAINE AND THE OTHER AREA MOVING ACROSS
DOWENAST AND EASTERN AREAS. WEAK AREA OF LOW PRES IS PASSING
ACROSS THE ST.LAWRENCE RIVER ATTM W/ITS ASSOCIATED COLD FRONT
PUSHING TOWARD WESTERN MAINE. A BLEND OF THE RUC AND NAM WAS USED
THROUGH LATE THIS MORNING W/TAKING SHOWER INTO NEW BRUNSWICK BY
15Z. THIS MATCHES UP WELL W/THE MID LEVEL FORCING EXITING THE
REGION BY 15Z AS IT LINES UP WELL W/THE RADAR ATTM. QPF FROM THIS
EVENT WILL BE AROUND .10-.15" AT BEST. MDL SOUNDINGS AND BUFKIT
PROFILES INDICATE THAT AIRMASS WILL DRY OUT ABOVE 850MBS ALLOWING
FOR MORE SUNSHINE. WSW WIND WILL TAKE HOLD LATER THIS MORNING INTO
THE AFTERNOON AS THE COLD FRONT SWINGS ACROSS THE REGION. THE NAM
HAS BACKED DOWN FROM ITS PREVIOUS FCSTS OF SHOWING SOME STRONGER
WINDS MIXING DOWN FROM 5K FT. THEREFORE...CUT BACK WIND GUSTS
TODAY TO AROUND 25 MPH ACROSS THE NORTHERN 1/2 OF THE CWA AS BOTH
THE GFS AND NAM SHOW LESS MIXING THIS AFTERNOON. WEAK CAA THROUGH
THE COLUMN TO TAKE HOLD THIS AFTERNOON AND W/A WESTERLY WIND IN
PLACE. THINKING HERE IS THAT TEMPERATURES WILL NOT BE AS WARM AS
MET GUIDANCE IS SHOWING W/MID TO UPPER 50S ACROSS THE NORTH AND
AROUND 60 FOR THE CENTRAL HIGHLANDS AND DOWNEAST AREAS. A BLEND OF
THE MAV AND LAMP GUIDANCE WAS USED FOR TEMPERATURES WHICH SHOWS
UPPER 40S TO LOWER 50S ACROSS THE NORTH AND MID TO UPPER 50S FOR
THE CENTRAL HIGHLANDS AND DOWNEAST.
FOR TONIGHT...CLOUDS WILL GIVE WAY TO MOSTLY CLEAR SKIES AS HIGH
PRES RIDGES ACROSS THE CWA. THIS WILL BE SHORT-LIVED AS CLOUDS
FROM THE NEXT SYSTEM WILL BE MOVING INTO THE REGION FROM THE WSW
LATER TONIGHT. THIS WILL KEEP TEMPERATURES FROM FALLING BACK TOO
LOW. ONCE AGAIN, FOLLOWED THE GMOS AND LAMP GUIDANCE FOR THE MINS
WHICH SHOWED MID-UPPER 30S ACROSS THE NORTH AND CENTRAL AREAS
WHILE LOWER 40S WILL DO FOR THE DOWNEAST REGION.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
LOW PRESSURE WILL TRACK TO OUR NORTH DURING WEDNESDAY...AS ANOTHER
WEAK DISTURBANCE TRACKS NORTHEAST OF THE SOUTHERN NEW ENGLAND
COAST. THIS WILL BRING INCREASING CLOUDS ACROSS THE REGION ON
WEDNESDAY BUT LITTLE IF ANY PRECIPITATION...AS MOST OF THE MOISTURE
ASSOCIATED WITH THE NORTHERN LOW REMAINS ACROSS QUEBEC...AND
MOISTURE WITH THE SOUTHERN SYSTEM REMAINS TO OUR SOUTH. WINDS
WILL BECOME MORE WESTERLY WEDNESDAY NIGHT WITH PARTLY CLOUDY SKIES
AND DRY WEATHER EXPECTED. AN UPPER LEVEL TROUGH WILL APPROACH FROM
THE WEST DURING THURSDAY. ANOTHER WEAK DISTURBANCE WILL MOVE
NORTHEAST FROM THE SOUTHERN NEW ENGLAND COAST DURING THE DAY
THURSDAY. ALTHOUGH MUCH OF THE MOISTURE ASSOCIATED WITH THIS
SYSTEM WILL REMAIN TO OUR SOUTH SOME LIGHT SHOWERS MAY REACH THE
DOWNEAST COAST LATER THURSDAY AS THE LOW TRACKS NORTHEAST.
HIGHS ON WEDNESDAY WILL BE ABOVE NORMAL...THEN BE NEAR NORMAL ON
THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE UPPER LEVEL TROUGH WILL MOVE EAST THURSDAY NIGHT WITH HIGH
PRESSURE BUILDING EAST ON FRIDAY. THE HIGH WILL MOVE EAST FRIDAY
NIGHT AND SATURDAY. A WARM FRONT WILL APPROACH SATURDAY NIGHT AND
LIFT NORTHEAST EARLY SUNDAY...FOLLOWED BY A COLD FRONT LATER SUNDAY
AFTERNOON. HIGH PRESSURE WILL BUILD EAST ON MONDAY.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: IFR/MVFR EARLY TODAY WILL GIVE WAY TO VFR BY LATE
MORNING INTO TONIGHT.
SHORT TERM: MAINLY VFR THROUGH THE PERIOD.
&&
.MARINE...
NEAR TERM: SCA WILL REMAIN IN PLACE FOR BOTH WINDS AND SEAS W/THE
SCA MOST LIKELY BE TRANSITIONED TO HAZARDOUS SEAS BY LATER TODAY
INTO EARLY TONIGHT AS A SWELL HANGS ON. USED A NAM12/GFS BLEND FOR
THE WINDS W/KEEPS GUSTS TO 25 KTS EARLY AND THEN WINDS DIMINISH
W/HIGH PRES SETTLING IN. ADJUSTED THE SEAS DOWN BY A FOOT AS THE
LATEST OBS ARE RUNNING A FOOT TOO LOW THAN FCST.
SHORT TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS WEDNESDAY AND
TROUGH THURSDAY AND THEN POSSIBLY INCREASE TO SCA LEVELS THURSDAY
NIGHT THROUGH SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1231 AM EST TUE NOV 15 2011
.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK NORTH OF MAINE OVERNIGHT...FOLLOWED
BY WEAK HIGH PRESSURE TUESDAY AND TUESDAY NIGHT. ANOTHER LOW PRESSURE
SYSTEM FROM THE OHIO VALLEY WILL MOVE OFF THE MID ATLANTIC COAST
TOWARD THE SOUTHERN GULF OF MAINE ON WEDNESDAY. HIGH PRESSURE AND
SOMEWHAT COLDER AIR WILL FOLLOW FOR THE LATE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATE: ADJUSTED THE POPS TO MATCH THE LATEST RADAR W/A SWATH OF
SHOWERS EXPANDING FROM INTERIOR DOWNEAST NORTHWARD INTO THE
CENTRAL HIGHLANDS. THE RUC HAD THE BEST HANDLE BUT STILL OFF ON
THE PLACEMENT AS IT THROWS HIGHEST PERCENTAGES & QPF ACROSS THE
NORTH AND NORTHWEST THIS MORNING. TEMPERATURES WERE ADJUSTED
UPWARD DUE TO INITIAL WAA SHOWN ON THE LATEST UA.
.PREVIOUS DISCUSSION...
RAIN SHOWERS WILL BECOME WIDESPREAD TONIGHT AS WEAK LOW PRESSURE
SLIDES ALONG A COLD FRONT THAT IS DRAPED JUST TO OUR NORTHWEST.
THIS WAVE IS MOVING VERY QUICKLY IN THE RAPID FLOW ALOFT...SO THIS
WILL BE A QUICK SHOT OF RAIN...STARTING LATE THIS EVENING AND
ENDING BY TUESDAY AFTERNOON. THE HEAVIEST AMOUNTS WILL BE ACROSS
THE SAINT JOHN VALLEY WHICH IS CLOSEST TO THE LOW AND FRONT AND
THEREFORE THE BEST FORCING. RAINFALL TOTALS HERE WILL BE A QUARTER
TO A THIRD OF AN INCH...AND LESS THAN A QUARTER OF AN INCH
ELSEWHERE. THE INFLUX OF MOISTURE AND THE CONTINUING SOUTHWEST
FLOW ALOFT WILL KEEP OVERNIGHT TEMPERATURES ON THE MILD SIDE ONCE
AGAIN AS LOWS WILL BE IN THE MID 40S TO AROUND 50 IN MOST
LOCATIONS.
FOR TUESDAY...THE AFOREMENTIONED COLD FRONT WILL MOVE SOUTH ACROSS
THE FORECAST AREA EARLY TOMORROW AND SHOULD CLEAR THE STATE BY
TUESDAY AFTERNOON. AS SUCH THE SHOWERS WILL QUICKLY COME TO AN END
AND SKIES WILL BECOME PARTLY TO MOSTLY SUNNY. THE CONCERN FOR
TUESDAY IS GUSTY WINDS BEHIND THE FRONTAL PASSAGE. A LOW LEVEL JET
OF 40+ KT WILL BE OVER NORTHERN NEW ENGLAND DURING THE LATE MORNING
AND EARLY AFTERNOON HOURS. A SHOT OF COOLER AIR ALOFT WILL ALLOW
THESE WINDS TO MIX TO THE SURFACE...SO EXPECT GUSTS OF 30 TO 35 MPH
THROUGH EARLY AFTERNOON. SUNSET WILL CUT OFF THE BEST MIXING SO
WINDS WILL SUBSIDE LATE TOMORROW AFTERNOON AND EVENING. EVEN WITH
THE COLD FRONT MOVING THROUGH HIGHS WILL BE VERY MILD ESPECIALLY
DOWNEAST. TEMPERATURES WILL MAX OUT IN THE LOWER TO MID 50S IN
NORTHERN MAINE AND AROUND 60 IN CENTRAL AND SOUTHERN AREAS.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
WINDS SHOULD DECREASE FAIRLY QUICKLY TUE EVE AS SFC-500M LAPSE
RATES STABILIZE AND LLVL WINDS DECOUPLE FROM STRONGER WINDS ALF.
SKIES WILL BEGIN FAIR...WITH INCREASING HI/MID CLDS LATE TUE NGT.
THIS INCREASE IN CLDS AND THE BEGINNING OF WEAK RETURN SRLY FLOW
WILL LIKELY KEEP OVRNGT LOWS ONCE AGAIN FROM REACHING THE FZG PT
ACROSS THE FA.
WED...CLDS WILL OVRSPREAD MUCH OF THE FA DURG THE MORN HRS AS A
WEAK WV OF LOW PRES MOVES ENE OFF THE NJ COAST. THE 12Z OPNL GFS
AND ACCOMPANYING ENS MEAN RUNS HAVE BACKED OFF THE NWRD
PROGRESSION OF OVRRNG RNFL WED AFTN AND ERLY EVE FROM THE 00 AND
06Z RUNS. GIVEN THE LATEST OPNL 12Z ECMWF...WHICH IS FURTHER NW
WITH RN SHIELD CUTOFF THAN THE GFS...WE WILL HOLD THE LINE WITH
THE CURRENT DISTRIBUTION OF POPS FROM THE PREVIOUS ERLY MORN
UPDATE...IN WHICH WE SHOW CHC RN POPS NE AND CNTRL PTNS OF THE FA
AND LIKELY POPS OVR DOWNEAST AREAS FOR THESE PDS. ANY RN SHOULD
TAPER TO SHWRS LATE WED EVE AND END OVRNGT. INITIALLY...A MID LVL
DRY SLOT SHOULD BRING SOME CLRG TO MOST OF THE FA LATE WED NGT.
THU WILL BEGIN MSLY SUNNY FOR THE FA...WITH COLD ADVCN SC AND
POSSIBLE RN/SN SHWRS MOVG INTO SPCLY THE NW HLF OF THE FA FROM ERN
QB AS AN UPPER LVL TROF APCHS. AFTER REACHING OVRNGT LOWS LATE WED
NGT OF JUST BLO FZG N TO SIG ABV FZL S...HI TEMPS THU WILL BE KEPT
SOME 5 TO 10 DEG COOLER THAN WED DUE TO LLVL COLD ADVCN AND CLD CVR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
WITH A COLD FRONT MOVING TO OUR EAST WE SHOULD BEGIN TO CLEAR OUT
FOR FRIDAY. THERE STILL COULD BE A FEW LINGERING SNOW SHOWERS
AROUND LATE THURSDAY NIGHT INTO EARLY FRIDAY MORNING. CLOUDS WILL
BEGIN TO THIN OUT AS HIGH PRESSURE MOVES IN ON FRIDAY. FRIDAY
NIGHT INTO SATURDAY MORNING BOTH THE GFS AND ECMWF BRING A WEAK
SHORTWAVE NORTH OF THE CWA. THIS COULD BE ENOUGH TO KICK OFF A FEW
RAIN AND SNOW SHOWERS ALL DAY SATURDAY. WITH A STILL UNSETTLED
PATTERN SET UP OVER THE AREA EXPECT MORE SHOWERS ON SUNDAY. A
STRONGER LOW PRESSURE SYSTEM MOVES TO THE NORTH OF THE AREA AGAIN
SUNDAY AND SUNDAY NIGHT. THIS AGAIN SHOULD BE SIGNIFICANT ENOUGH
TO BRING RAIN AND SNOW SHOWERS TO THE AREA...ESPECIALLY THE
NORTHERN AREAS. AFTER THAT SYSTEM MOVES OUT HIGH PRESSURE MOVE IN
AGAIN MONDAY. EXPECT TEMPERATURES TO GO BACK TO MORE SEASONAL
READINGS DURING THE LONG RANGE PERIOD. USED A BLEND OF GFS AND
GMOS FOR THE PERIOD. FOR TEMPERATURES LEANED MORE ON RAW GFS GUIDE
DUE TO UNSETTLED PATTERN.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR EXPECTED THROUGH THIS EVENING...THEN ALL TERMINALS
DECREASING TO IFR/LIFR DUE TO LOW CEILINGS IN RAIN SHOWERS THROUGH
MUCH OF THE OVERNIGHT. CONDITIONS WILL SLOWLY IMPROVE TO VFR FROM
SOUTH TO NORTH LATE TUESDAY AFTERNOON. ALL SITES WILL BE VFR BY 16Z
WITH CLEARING SKIES THEREAFTER. WINDS BECOME GUSTY FROM THE WEST
FOLLOWING A FRONTAL PASSAGE TUESDAY MORNING...WITH GUSTS OF 30 TO 35
MPH EXPECTED.
SHORT TERM: MSLY VFR TUE NGT INTO WED MORN...WITH SRN TAF SITES
AND POSSIBLY KHUL BECOMING MVFR WED AFT INTO WED EVE IN CLGS AND
POSSIBLY VSBY WITH LGT RN. ALL SITES BECOME VFR LATE WED NGT AND
THU MORN...WITH NRN TAF SITES BECOMING MVFR WITH BKN-OVC COLD
ADVCN SC CLD CVR MIDDAY THU INTO FRI MORN. ALL TAF SITES VFR AGAIN
MIDDAY FRI INTO FRI EVE...WITH NRN TAF SITES POSSIBLY BECOMING
MVFR VERY LATE FRI INTO SAT MORN IN LGT OVRRNG PRECIP.
&&
.MARINE...
NEAR TERM: THE SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH
TUESDAY EVENING. WINDS WILL REMAIN AT 15-25 KT WITH GUSTS TO 30 KT
AS LOW PRESSURE MOVES TO THE NORTH OF THE STATE TONIGHT...THEN A
COLD FRONT MOVES ACROSS THE REGION TOMORROW. WINDS WILL BEGIN TO
DECREASE LATE TUESDAY AFTERNOON BUT SEAS WILL REMAIN HIGH THROUGH
THE PERIOD.
SHORT TERM: SCA FOR AT LEAST SEAS WILL BE NEEDED TUE NGT AS WINDS
DROP BLO SCA CRITERIA. THE NEXT OPPORTUNITY FOR SCA CONDITIONS
WILL BE LATE WED NGT INTO THU WITH THE NW PRES GRAD WINDS BEHIND
THE DEPARTING LOW MOVG ENE FROM THE SRN GULF OF ME INTO THE OPEN
ATLC. WE USED A BLEND OF NAM12 AND GFS40 FOR WINDS AND KEPT CLOSE
TO WW3 FOR THIS PTN OF THE FCST.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
617 PM EST WED NOV 16 2011
.SHORT TERM /TONIGHT AND THURSDAY/...
POTENT SHORTWAVE THAT MOVED THROUGH THE CWA LAST NIGHT WILL CONTINUE
NE THROUGH QUEBEC TONIGHT...LEAVING THE AREA UNDER AN UPPER TROUGH
FOR MUCH OF THE SHORT TERM PERIOD. LOW/MID LVL MOISTURE BEHIND THE
WAVE HAS SETTLED OVER THE NE HALF OF THE CWA TODAY AND IS EXPECTED
TO REMAIN THROUGH THE FIRST HALF OF THURS. THIS HAS AIDED SOME
SHOWER DEVELOPMENT OVER THE ERN LK THROUGH THE DAY. THESE BANDS HAVE
A NW TO SE APPEARANCE DUE TO THE NW WINDS ALOFT...BUT THE LLVL WINDS
W TO WNW WINDS HAVE BEEN GRADUALLY PUSHING THEM E. DRIER LLVL AIR
OVER WRN LK SUPERIOR HAS TRIED TO LIMIT LES EXTENT OVER THE WRN
U.P...BUT AN ADDITIONAL AREA OF LOW/MID LVL MOISTURE OVER NRN MN
/PRODUCING SCATTERED SHSN/ SHOULD BEGIN TO MOVE INTO THE AREA THIS
EVENING.
WITH THE AREA BETWEEN THE HIGH TO THE SW AND THE EXITING LOW IN
QUEBEC...EXPECT WNW FLOW TO CONTINUE THROUGH THURS. A LINGERING
TROUGH FROM THE EXITING LOW OVER ERN LK SUPERIOR FOR TONIGHT INTO
THURSDAY WILL HELP TO FOCUS WINDS A LITTLE MORE OUT OF THE NW OVER
NRN LUCE AND FAR ERN ALGER COUNTY AND INCREASE THE LLVL CONVERGENCE
IN THAT AREA. RUC ANALYSIS OF H850 TEMPS SHOWS VALUES RANGING FROM
-11C OVER WRN LK SUPERIOR TO -8C OVER ERN LK SUPERIOR. THESE TEMPS
SHOULD FALL A COUPLE DEGREES BY 12Z THURS WITH THE SECONDARY SURGE
OF COLD AIR BEHIND A WEAK H850 TROUGH AND REMAIN THROUGH THE DAY
THURS. THIS CREATES DELTA-T VALUES IN THE UPPER TEENS ACROSS THE LK
THROUGH THE PERIOD.
OVER THE W...PARAMETERS HAVE REALLY COME TOGETHER FOR MODERATE TO
POTENTIALLY HEAVY LES TONIGHT INTO TOMORROW MORNING. WITH THE
SLIGHTLY COLDER H850 TEMPS THERE...EXPECT MUCH OF THE LK INDUCED
FORCING TO BE RIGHT IN THE DGZ. MODELS STILL HINTING AT LLVL DRY AIR
OVER THE WRN CWA KEEPING CLOUD BASES NEAR 3KFT THROUGH THIS
EVENING...WHICH WILL LIMIT THE DEPTH OF THE CLOUD WITH EQL VALUES
FROM 7-10KFT. BUT H925-850 MOISTURE CURRENTLY LOCATED OVER NRN MN
SHOULD PUSH OVER WRN LK SUPERIOR AND THE WRN CWA OVERNIGHT TONIGHT
AND INTO TOMORROW MORNING. THIS SHOULD PROVIDED ADDITIONAL LLVL
MOISTURE TO REALLY ENHANCE THE LES IN THE WNW FAVORED LOCATIONS. LES
PARAMETER IS SHOWING THIS WELL...WITH A DIMINISHING TREND LATE THIS
AFTN AND INTO THE EVENING...BEFORE GREATLY INCREASING OVERNIGHT AND
INTO THURS MORNING. BIGGEST CONCERN IS THE WHAT THE EQL WILL BE.
BUFKIT SOUNDINGS DO HAVE SOME VARIABILITY ON IF THE EQL/S WILL RISE
TOWARDS 12-15KFT OVERNIGHT INTO THURS MORNING...WHICH DEPENDS ON A
DEGREE F OR TWO DIFFERENCE IN THE LK TEMPS. IF THAT OCCURS...COULD
SEE SNOW AMOUNTS BEING HIGHER THAN EXPECTED. FELT THE CURRENT
FORECAST WAS ON TRACK WITH HIGH END ADVISORY AMOUNTS WHERE THERE
WILL LIKELY BE ENHANCED CONVERGENCE OVER NRN ONTONAGON AND CENTRAL
HOUGHTON COUNTIES. THE EVENING SHIFT WILL NEED TO MONITOR TRENDS AND
IF THE SNOW BECOMES HEAVY EARLIER THAN EXPECTED...MAY NEED TO BUMP
UP THE ADVY TO A WARNING.
OVER THE E...WITH THE DEEPER MOISTURE AND EQL NEAR 15KFT FROM THE
EXITING WAVE...LES PARAMETERS ARE MUCH BETTER IN THIS AREA AND
SHOWING POTENTIAL FOR MODERATE TO HEAVY SNOW. THERE POTENTIALLY TWO
LIMITING FACTORS ON SNOW AMOUNTS REACHING WARNING CRITERIA.
FIRST...PREVIOUS SHIFT MENTIONED THE POTENTIAL FOR SNOW PELLETS OR
GRAUPEL AT TIMES TONIGHT...WHICH SEEMS REASONABLE THIS EVENING WITH
THE SLIGHTLY WARMER H850 TEMPS KEEPING THE BEST OMEGA BELOW THE DGZ.
BUT...AS TEMPS COOL OVERNIGHT BEHIND THE H850 TROUGH...EXPECT A
TRANSITION TO MAINLY SNOW. SECOND...THE WIND DIRECTION REMAINS A
CONCERN FOR TONIGHT. WITH NW WINDS SHIFTING MORE WRLY THROUGH THE
DAY TODAY...THE MAIN PCPN HAS BEEN RUNNING NEARLY PARALLEL TO SHORE
THIS AFTN. MODELS SHOW A SLIGHT WNW SHIFT TO THE H925 WINDS THIS
EVENING...BUT NOT SURE IF THIS WILL BE ENOUGH TO SLIDE THE DOMINATE
BAND ONSHORE FROM GRAND MARAIS EAST ALONG THE LUCE COUNTY SHORELINE.
WITH THE GEM/ECMWF/GFS AND LOCAL WRF SHOWING THE LINGERING SFC
TROUGH TIGHTENING UP OVER THE FAR ERN LK OVERNIGHT TONIGHT AND
DROPPING SE THURS MORNING...EXPECT THIS TO SHIFT THE WINDS NW ENOUGH
TO PUSH THE DOMINATE BAND INTO LUCE COUNTY. THUS...WITH
MODERATE/HEAVY SNOW...ALONG WITH GUSTY WINDS UP TO 30MPH...HAVE
SWITCHED THE LES WATCH OVER TO A WARNING FOR LUCE. WITH THE
UNCERTAINTY ON THE EXACT LOCATION OF THE BAND FOR THE GRAND MARAIS
AREA OF ALGER...HAVE SWITCHED THAT WATCH OVER TO AN LES ADVY...BUT
THERE REMAINS SOME BUST POTENTIAL BOTH WAYS. EXPECT THIS PERIOD OF
HEAVY SNOW TO CONTINUE THROUGH THURS MORNING UNDER THE NW WINDS.
CURRENT FORECAST HAS SNOWFALL AMOUNTS EXCEEDING A FOOT FOR PORTIONS
OF NRN LUCE COUNTY BY 00Z FRI.
DRIER MID LVL AIR BEGINS TO MOVE OVER THE SW HALF OF THE CWA THURS
AFTN...LOWERING THE EQL/S TOWARDS 5-6KFT BY 00Z FRI. THIS WILL
DIMINISH THE INTENSITY OF THE SHOWERS OVER THE W. OVER THE E...THESE
LESS FAVORABLE LES CONDITIONS DON/T ARRIVE UNTIL LATE THURS AFTN AND
INTO THURS EVENING AND HAVE ENDED THE WARNING AT 00Z.
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE SFC MAP AT 00Z STRONG HIGH PRESSURE ACROSS THE TN VALLEY WILL
EXTEND A RIDGE ACROSS WI AND WESTERN LAKE SUPERIOR...WITH A WEAK SFC
TROUGH EXTENDING FROM THE MAIN LOW OVER FAR EASTERN CANADA TO JUST
EAST OF LAKE SUPERIOR. THIS WILL ALLOW THE FOCUS FOR HEAVIER SNOW TO
DIMINISH ACROSS LAKE SUPERIOR...WITH NW WINDS BECOMING MORE AND MORE
WESTERLY AS THE EVENING PROGRESSES.
THE HIGH AMPLITUDE 500MB RIDGE OVER THE PACIFIC NORTHWEST AND
WESTERN CANADA WILL FLATTEN AS IT SLIDES ACROSS THE NORTHERN PLAINS
AND SOUTHERN MANITOBA BY 00Z FRIDAY. IT WILL STILL BE ENOUGH TO AT
LEAST TEMPORARILY SWEEP THE TROUGHS EAST OF THE AREA THURSDAY NIGHT
THROUGH THE START OF THE WEEKEND. HOWEVER...THE MAIN CULPRIT WILL
BUDGE LITTLE OVER THE SECOND HALF OF THE WORK WEEK...THAT BEING THE
500MB LOW SPINNING NEAR HUDSON BAY.
THE FAST SOUTHWESTERLY FLOW WILL RETURN...WITH THE APEX OF THE RIDGE
EXITING THE UPPER GREAT LAKES FRIDAY AFTERNOON/EVENING. ONE TROUGH
OVER NORTHERN MANITOBA AT 00Z SATURDAY SHOULD CROSS ONTARIO SATURDAY
AFTERNOON/EVENING. BEHIND THIS FEATURE A MORE DISTINCT TROUGH WILL
WASH OUT ALONG THE CANADIAN/U.S. BORDER...WITH A BROAD TROUGH
EXPECTED ACROSS LAKE SUPERIOR AND UPPER MI SATURDAY EVENING THROUGH
NEXT TUESDAY NIGHT. THE RESULT AT THE SFC WILL BE THE WEAKENING OF
THE 995MB SFC LOW CENTERED ACROSS SOUTHERN SASKATCHEWAN AT 00Z
FRIDAY...TO 1003MB BY 00Z SATURDAY JUST NW OF LAKE SUPERIOR. EVEN
WITH THE WEAKENING OF THIS SYSTEM THE TIGHTENING PRESSURE GRADIENT
WILL RESULT IN STRONGER SW WINDS AT THE SFC FRIDAY INTO EARLY FRIDAY
EVENING...MAINLY ACROSS THE EASTERN HALF OF THE CWA. THE RESULT WILL
BE A TROUGH OF LOW PRESSURE AT THE SFC EXTENDING BETWEEN 2 STRONGER
LOW OVER HUDSON BAY AND KANSAS AT 12Z SATURDAY OVER THE EAST HALF.
LOOK FOR A LOW TO PUSH NORTHEASTWARD ALONG THIS TROUGH FROM THE
CENTRAL TO SOUTHERN PLAINS. MODELS CONTINUE TO PLAY THE LOW TRACKING
NEAR THE STRAITS AROUND 06Z SUNDAY...WITH THE NAM FARTHEST
NORTH...AND THE ECMWF ON THE SOUTHERN END OF THE FORECAST ENVELOP.
THE CANADIAN LOOKS TO BE ABOUT 6 HOURS SLOW. MODERATE TO HEAVY SNOW
ACCUMULATIONS REMAIN POSSIBLE OVER THE WESTERN HALF OF UPPER MI
UNTIL HIGH PRESSURE BUILDS IN FROM THE WEST SUNDAY AFTERNOON.
LOOKING A BIT FARTHER OUT...THERE ARE A COUPLE OF 500MB WAVES WITHIN
THE BROAD TROUGH /WESTERLY FLOW/ THAT ARE DIFFICULT TO FORECAST. THE
FIRST WAVE FOR MONDAY IS MORE DISTINCT OFF THE 16/12Z RUN OF THE
GFS...BUT IS SIMILAR TIMING WISE...BUT IS MUCH WEAKER THAN WHAT IS
SHOWN OFF THE 16/00Z ECMWF. THE CANADIAN IS OUT OF PHASE WITH THE
GFS AND ECMWF STARTING AROUND 12Z MONDAY...OR ABOUT 6 HOURS SLOWER.
A SIMILAR TREND WAS NOTED WITH THE TUESDAY AFTERNOON/EVENING WEAK
TROUGH...WHERE THE GFS TIGHTENED UP THE TROUGH A BIT MORE THAN THE
ECMWF. FORECAST MODELS ARE ABOVE NORMAL CONSISTENCY WISE FOR NEXT
WEDNESDAY...WITH A LARGE 500MB RIDGE BUILDING IN FROM THE PLAINS
STATES.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
COLD AIR MOVING ACROSS LAKE SUPERIOR WILL PRODUCE CLOUDS AND LAKE
EFFECT SNOW FOR THE WEST TO NORTHWEST WIND SNOW BELTS FOR THE TAF
PERIOD. THIS WILL LARGELY AFFECT KCMX WITH PERIODS OF MVFR CIGS
AND IFR VSBYS. WITH KIWD NOT BEING UNDER FAVORABLE FLOW FOR
SNOW...HAVE LEFT OUT MENTION...BUT DID KEEP MVFR CIGS FOR THE
OVERNIGHT PERIOD FROM MOISTURE CURRENTLY IN NRN MN. KSAW WILL SEE
VFR CONDITIONS.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
LOW PRESSURE ACROSS CENTRAL ONTARIO WILL KEEP A WEAK TROUGH ACROSS
EASTERN LS OVERNIGHT...WHICH WILL ASSIST IN FOCUSING THE STRONGER
GALE FORCE WINDS OF 35KTS OVER THE EASTERN HALF OF LS THROUGH THIS
EVENING. LOOK FOR A RIDGE OF HIGH PRESSURE TO BUILD IN THURSDAY INTO
THURSDAY NIGHT...WITH GUSTS CONTINUING 20 TO 30KTS. LOW PRESSURE
ACROSS SOUTHERN SASKATCHEWAN THURSDAY NIGHT WILL FILL SLIGHTLY JUST
NORTH OF LS FRIDAY NIGHT. AHEAD OF THIS FEATURE...STRONG SW WINDS
FRIDAY INTO FRIDAY NIGHT MAY RESULT IN A FEW GALE FORCE GUSTS ACROSS
EASTERN LS. EXPECT A NEARLY STATIONARY TROUGH OVER EASTERN LS ON
SATURDAY. LOW PRESSURE OVER THE CENTRAL PLAINS SATURDAY WILL MOVE
ALONG THE TROUGH...FILLING SLIGHTLY ACROSS NORTHERN LOWER MICHIGAN
BY SATURDAY NIGHT...WITH A BRIEF PERIOD OF NE GALES TO 35KT SATURDAY
AFTERNOON THAT MAY TRANSITION ACROSS THE ENTIRE LAKE AS WINDS TURN
MORE NORTHWESTERLY AS THE LOW EXITS NE. HIGH PRESSURE SHOULD SLIDE
IN FROM THE WEST SUNDAY...BEFORE SLOWLY DIPPING TO THE LOWER GREAT
LAKES ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THURSDAY FOR MIZ001>003-
084.
LAKE EFFECT SNOW WARNING FROM 10 PM THIS EVENING TO 7 PM EST
THURSDAY FOR MIZ007.
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 5 PM EST
THURSDAY FOR MIZ006.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ248>251-265>267.
LAKE MICHIGAN...NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...07
MARINE...SRF/SF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
600 AM CST TUE NOV 15 2011
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
LOW PRESSURE AND A TRAILING COLD FRONT OVER WESTERN MINNESOTA WILL
MOVE ACROSS THE CWA THIS MORNING. A SECOND AND STRONGER COLD
FRONT OVER THE DAKOTAS WILL MOVE THROUGH DURING THE AFTERNOON AND
EVENING HOURS. TWO PRECIPITATION THREATS EXIST TODAY. THE FIRST
IS OVER SE MN AND PARTS OF WEST CENTRAL WI THIS MORNING WHERE
STRONG WAA AND ADIABATIC OMEGA ARE MOVING THROUGH. ADDED SCATTERED
SPRINKLES THROUGH MID MORNING FOR THESE AREA. THE OTHER AREA FOR
PRECIPITATION TODAY IS ACROSS THE FAR NORTHERN CWA AHEAD OF A
POTENT SHORT WAVE MOVING ACROSS NORTH DAKOTA. ALTHOUGH QUITE A BIT
OF VARIANCE EXISTS BETWEEN MODEL SOLUTIONS ON THE LOCATION OF THE
PRECIPITATION...THERE IS AT LEAST A CHANCE FOR PRECIPITATION
ACROSS OUR FAR NORTHERN CWA THIS AFTERNOON...AND SMALL POPS WERE
ADDED. NAM BEST LI BECOMING MORE NEGATIVE WITH TIME FOR THIS
AFTERNOON JUST NORTH OF OUR MN CWA...SO SOME LIGHTNING CAN/T BE
RULED OUT. THE PRECIPITATION THREAT WILL END EARLY THIS EVENING
ACROSS WEST CENTRAL WI.
STRONG WEST WINDS WILL ALSO DEVELOP TODAY IN THE WAKE OF THE
FRONTS. STRONG CAA IS SEEN THIS AFTERNOON ACROSS THE MN RIVER
VALLEY. IN ADDITION...SIMULATED WATER VAPOR IMAGERY SHOWS EXTREME
DRYING ACROSS FAR SOUTHERN MINNESOTA ALONG WITH A PV BOOT. LOW
LEVEL WINDS ARE WELL ALIGNED IN THE VERTICAL WITH THE NAM/GFS
BUFKIT PROFILE DATA INDICATING ADIABATIC LAPSE RATES TO AT LEAST
750 MB. 200FT WINDS ARE NEAR 30 KNOTS WITH MID LEVEL MOMENTUM
TRANSFER REACHING THE UPPER 30 KNOT RANGE. TOP OF THE CHANNEL HITS
45 KNOTS. HENCE...A WIND ADVISORY WAS ISSUED FOR MUCH OF WEST
CENTRAL THROUGH SOUTH CENTRAL MN.
IT WILL BE COLDER FOR WEDNESDAY AND THURSDAY. THERE WILL BE SOME
CLOUDINESS ON WEDNESDAY WITH HIGH PRESSURE AND CLEARING FOR
THURSDAY. CLOUDS WILL COME BACK ON FRIDAY AS A LOW PRESSURE SYSTEM
BEGINS TO TAKE SHAPE OVER THE CENTRAL ROCKIES. GEM/GFS/ECMWF TRACK
THE LOW FROM WESTERN IA TO CENTRAL WI SATURDAY AFTERNOON AND
EVENING. ITS A RATHER FAST MOVING SYSTEM WITH AN OPEN WAVE ALOFT.
BEST FORCING AND DENDRITIC GROWTH ZONE WOULD FAVOR AREAS OF
CENTRAL MN FOR ACCUMULATING SNOW ATTM. LIKELY POPS ARE NOW IN
PLACE. THE WEEKEND WILL END COLD WITH HIGH PRESSURE OVERHEAD.
LITTLE PRECIPITATION IS SEEN EARLY NEXT WEEK.
&&
.AVIATION.../12Z TAF ISSUANCE/
RATHER MUDDY UPPER TROUGH WILL REMAIN IN PLACE THIS PERIOD...WITH
BOUTS OF MAINLY MID LEVEL CLOUD COVER EXPECTED TO CONTINUE.
MORNING WAA PRECIP OVER CENTRAL MN AND SE MN MAY BRING A SPRINKLE
OR TWO TO AXN/EAU. OTHERWISE...CENTRAL MN BAND OF FORCING WILL
REMAIN NORTH OF THE TERMINALS...WHILE PRECIP ASSOCIATED WITH WAA
HEADING FOR EAU WILL BE MOSTLY VIRGA. STRONG WAVE OVER NODAK WILL
BRING ANOTHER SHOT AT SEEING PRECIP THIS AFTERNOON TO MAINLY
CENTRAL MN. AXN LOOKS TO BE CLOSEST TO UPPER FORCING ASSOCIATED
WITH THIS WAVE...SO INCLUDED TEMPO PRECIP MENTION ONLY THERE...BUT
COULD SEE ACTIVITY DIP AS FAR SOUTH AS STC/RNH. STRONG WINDS FOR
TODAY STILL LOOKS LIKE A CERTAINTY...ESPECIALLY ACROSS MN.
HOWEVER...FRONT MOVING TROUGH A BIT SLOWER THAN WHAT WAS
PREVIOUSLY THOUGHT. GFSLAMP/HRRR/LOCAL WRF ALL SIMILAR WITH WIND
FORECAST TODAY...SO FOLLOWED THOSE FOR TIMING DIRECTION SHIFTS
ACROSS THE AREA. STRONGEST WINDS TODAY LOOK TO BE DOWN THE MN
RIVER FROM WEST CENTRAL INTO SOUTH CENTRAL MN...WITH GUSTINESS
LIKELY BEING LIMITED OVER WRN WI...WHERE PRESSURE GRADIENT LOOKS
TO REMAIN BAGGY UNTIL THIS EVENING.
KMSP...WINDS BACKED QUITE A BIT MORE THAN EXPECTED OUT AHEAD OF
THE PRESSURE TROUGH/FRONT OVERNIGHT. GFSLAMP WIND FORECAST LOOKED
REASONABLE THIS MORNING...AND HAD SUPPORT FROM HRRR AND LOCAL WRF
HIGH RES MODEL RUNS...SO STUCK CLOSE TO IT FOR THE WIND FORECAST.
KEPT WIND SPEEDS AS IS...AS HRRR WOULD INDICATE STRONG NODAK WAVE
WILL HAVE A WEAK LOW MOVE ACROSS WITH IT...POSSIBLY SUPPRESSING
PRESSURE GRADIENT AND WINDS OVER ERN MN UNTIL LATE THIS
AFTERNOON. NOT EXPECTING ANY PRECIP...BUT THERE IS A SMALL CHANCE
THAT A SHOWER COULD PASS THROUGH BETWEEN 20Z AND 23Z AS THE NODAK
WAVE MOVES THROUGH...BUT EXPECTING BEST PRECIP CHANCES TO REMAIN
NORTH.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY FROM 11 AM THIS MORNING TO 5 PM CST THIS AFTERNOON
FOR BLUE EARTH-BROWN-CHIPPEWA-FARIBAULT-FREEBORN-LAC QUI
PARLE-LE SUEUR-MARTIN-NICOLLET-REDWOOD-RENVILLE-SIBLEY-
STEELE-STEVENS-SWIFT-WASECA-WATONWAN-YELLOW MEDICINE.
WI...NONE.
&&
$$
RAH/MPG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
825 PM EST WED NOV 16 2011
.SYNOPSIS...
A COLD FRONT OVER THE TENNESSEE VALLEY WILL SLIDE EASTWARD BRINGING
SHOWERS AND A CHANCE OF THUNDERSTORMS...INCLUDING SEVERE
WEATHER...TONIGHT THROUGH THURSDAY MORNING. MUCH COOLER AND DRIER
AIR WILL FOLLOW LATE THURSDAY AND FRIDAY. HIGH PRESSURE WILL MOVE
OVERHEAD WITH TEMPERATURES MODERATING DURING THE WEEKEND. A SECOND
FRONT WILL DROP SOUTH THROUGH THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 815 PM WEDNESDAY...THE HIGHER WINDS ALOFT WITH THE BETTER
ORGANIZED CONVECTION ACROSS THE AREA CONTINUES TO HAVE A DIFFICULT
TIME REACHING THE SFC. WOULD HAVE THOUGHT SOME OF THE BETTER LOOKING
BOW SIGNATURES WOULD HAVE FORCED THOSE STRONGER WINDS THROUGH THE
WEAK SFC STABLE LAYER. WITH SOME OF THE STRONGER LOW LEVEL JETTING
YET TO PUSH ACROSS THE FA...IT WILL LIKELY BE ONLY TIME BEFORE SOME
OF THESE STRONGER WIND GUSTS ASSOCIATED WITH THESE BOWS MAKE IT TO
THE SFC. TOR WATCH VALID THROUGH MIDNIGHT FOR PORTIONS OF THE FA.
ONE TO 3 CELLS...IN A BROKEN LINE FROM DILLON COUNTY ACROSS FLORENCE
TO SOUTHERN WILLIAMSBURG COUNTY...LOOK TO HAVE THE BETTER POTENTIAL
FOR ISOLATED SEVERE.
PREVIOUS DISCUSSION.................................................
AS OF 300 PM WEDNESDAY...TROPICAL WARMTH AND HUMIDITY WILL COME TO A
CRASHING HALT LATE TONIGHT AS A STRONG COLD FRONT ARRIVES FROM THE
WEST. THE TRANSITION FROM A TROPICAL TO AN ARCTIC AIRMASS WILL NOT
BE AN EASY ONE...AND SEVERE THUNDERSTORMS APPEAR POSSIBLE ACROSS THE
EASTERN CAROLINAS TONIGHT.
INSTABILITY PARAMETERS ARE IMPRESSIVE FOR A COOL-SEASON EVENT.
ALTHOUGH SURFACE CAPE FALLS AWAY TO A FEW HUNDRED J/KG AFTER DARK
WITH 75-100 J/KG OF INHIBITION TO OVERCOME...STARTING TO LIFT A
PARCEL FROM AROUND 925 MB YIELDS 600-1500 J/KG OF UNINHIBITED CAPE
AIDED BY REASONABLY STEEP MID AND UPPER LEVEL LAPSE RATES. UNLIKE
OUR TYPICAL WINTERTIME "SEVERE SHOWER" SCENARIOS THERE COULD
ACTUALLY BE DEEP (40+ KFT) CONVECTION TONIGHT. WIND SHEAR PARAMETERS
ARE ALSO IMPRESSIVE: 50-60 KT OF 0-6 KM BULK SHEAR...200-300 M^2/S^2
0-3 KM HELICITY...AND 50 KT WIND SPEEDS WITHIN 2500 FEET OF THE
GROUND ALL POINT TOWARD ORGANIZED STORMS...PERHAPS EVEN
SUPERCELLS...WITH THE POTENTIAL FOR WIND DAMAGE AND TORNADOES.
SYNOPTICALLY A 300 MB JET STREAK WILL MOVE EAST THROUGH THE
MID-ATLANTIC STATES TONIGHT. THIS WILL PLACE THE EASTERN CAROLINAS
WITHIN THE RIGHT-ENTRANCE REGION OF THE JET STREAK AIDING IN
DEEP-LAYER LIFT. TIMING-WISE...THE LAST THREE RUNS (15-16-17Z) OF
THE HRRR RAPID UPDATE MODEL ALL PLACE THE LEADING EDGE OF THE SQUALL
LINE IN WESTERN DARLINGTON COUNTY AT 7 PM...MOVING INTO FLORENCE...
DILLON AND LUMBERTON BY 8 PM...AND TO THE COAST BETWEEN 10 PM AND
MIDNIGHT. OUR HIGHEST POPS (80-90%) EXTEND FROM FLORENCE...MARION
AND MYRTLE BEACH NORTHWARD THROUGH SOUTHEASTERN NORTH CAROLINA.
LOWER POPS (50-60%) ARE FORECAST SOUTH INTO THE GEORGETOWN AREA
WHERE THIS FIRST BATCH OF CONVECTION MAY BE TOO FAR NORTH FOR
IMPACTS. ADDITIONAL SHOWERS AND POSSIBLY THUNDERSTORMS MAY DEVELOP
BEHIND THIS FIRST BATCH...ASSOCIATED WITH SUBTLE UPPER DISTURBANCES
WORKING ON RESIDUAL ELEVATED INSTABILITY. THIS SECOND BATCH OF
CONVECTIVE ACTIVITY COULD CONTINUE UP UNTIL THE TIME OF THE FRONTAL
PASSAGE AROUND DAYBREAK THURSDAY.
LOW TEMPERATURES TONIGHT WILL BE TRICKY WITH THE SURFACE COLD FRONT
LIKELY ARRIVING AROUND 12Z. WE ARE FORECASTING MID 60S ON THE COAST
AND 59-63 INLAND...HOWEVER THERE IS SIGNIFICANT BUST POTENTIAL IN
EITHER DIRECTION IF THE FRONT IS ONLY A COUPLE HOURS FASTER OR SLOWER
THAN IS CURRENTLY FORECAST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...CONCERN DURING THE PERIOD REVOLVES AROUND
COLD FRONTAL PASSAGE AND ASSOCIATED CONVECTION EARLY
THURSDAY...FOLLOWED BY A DRASTIC DROP IN TEMPERATURES WHICH WILL
MAKE IT FEEL ONCE AGAIN LIKE EARLY WINTER.
STRONG COLD FRONT WILL BE JUST INSIDE WESTERN EDGE OF THE CWA
THURSDAY MORNING AND RAPIDLY MOVING EAST. THE UNCERTAINTY WITH
STRENGTH OF CONVECTION REVOLVES AROUND THE FACT THAT FROPA IS
OCCURRING AT A NON-IDEAL TIME WITH RESPECT TO INSTABILITY.
HOWEVER...PARAMETERS DO SUGGEST THAT CONVECTION WILL BE ONGOING AT
THE BEGINNING OF THE PERIOD...ESPECIALLY ACROSS THE EASTERN ZONES.
RIDGE OF LOW LEVEL THETA-E AIR REMAINS IN PLACE THROUGH THURSDAY
MORNING ALONG WITH STEEP MID LEVEL LAPSE RATES AND PWATS NEAR 1.5
INCHES. ADDITIONALLY...SOME PVA NEAR A VORT LOBE TRAILING THROUGH
THE EASTERN CAROLINAS...LOCALLY ENHANCED DIFFLUENCE IN THE RIGHT
ENTRANCE REGION OF AN EXITING UPPER JET...AND THE COLD FRONT ITSELF
WILL HELP FORCE SOME LIFT AND KEEP CONVECTION GOING THROUGH LATE
MORNING. 12 HOUR SREF PRECIP PROBS DO NOT DROP BELOW 50 PERCENT
UNTIL AFTER 03Z FRIDAY...SO ALTHOUGH THE SEVERE THREAT AFTER SUNRISE
THURSDAY APPEARS LIMITED WILL KEEP TSTM MENTION THROUGH LATE MORNING
ALONG THE COAST...WITH SOME LIGHT RAIN POSSIBLE UNTIL EARLY AFTN.
FROPA OCCURS ACROSS THE ENTIRE CWA BY THE AFTN BRINGING AN END TO
PRECIP THROUGH THE REMAINDER OF THE SHORT TERM. DRYING WILL OCCUR
BEHIND FRONT AS HIGH PRESSURE BUILDS INTO THE REGION...BUT POST
FRONTAL CLOUD COVER/STRATUS WILL EXIST THROUGH MUCH OF THURSDAY
BEFORE CLEARING ON FRIDAY.
THE HIGHEST TEMPS OF THE PERIOD WILL OCCUR THURSDAY MORNING ALONG
AND AHEAD OF THE FRONT...DROPPING RAPIDLY IN THE AFTN AS STRONG CAA
DEVELOPS. LARGE BUST POTENTIAL ON MAX TEMPS THURSDAY DEPENDING ON
EXACT TIMING OF FROPA...BUT EXPECT TEMPS AROUND 60 INLAND...MID 60S
AT THE COAST AT DAYBREAK THURSDAY...THEN FALLING THROUGH THE DAY.
MEX/MAV IN AGREEMENT WITH MAX TEMPS FRIDAY IN THE MID 50S...BUT
GUIDANCE HAS A TENDENCY TO OVER FORECAST HIGHS THE DAY AFTER A
STRONG FROPA. WILL TREND MAXES DOWN TO THE LOW/MID 50S...BUT NOTE
THIS MAY STILL BE TOO WARM. MINS EACH NIGHT WILL BE IN THE MID 30S
AT THE COAST...AROUND 30 IN THE COLDER SPOTS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...WEAK RIDGING ALOFT WILL BECOME SUPPRESSED
LATE IN THE PERIOD AS 5H FLOW BECOMES MORE ZONAL. MUCH OF THE PERIOD
WILL BE DOMINATED BY ELONGATED SURFACE HIGH WITH A WEAK COASTAL TROF
DEVELOPING SAT INTO SUN. COASTAL TROF LOOKS PRETTY WEAK SO DO NOT
THINK PRECIP WILL NOT BE AN ISSUE. BACKDOOR COLD FRONT STALLED NORTH
OF THE AREA MON WILL PUSH SOUTH ACROSS THE AREA TUE. NOT MUCH
FORCING ALONG THE FRONT AS IT HEADS SOUTH. FROPA WILL BE MARKED BY
AIR MASS CHANGE BUT VERY LITTLE IF ANY PRECIP. WEAK ISENTROPIC LIFT
LATE IN THE PERIOD AS MID LEVEL RIDGE SHIFTS EAST WILL PROVIDE THE
BEST CHANCE FOR PRECIP DURING THE PERIOD. HOWEVER...GIVEN THE
UNCERTAINTY WITH RESPECT TO THE EVENT PLAN TO CARRY SILENT POP FOR
NOW. TEMPERATURES WILL START OUT NEAR CLIMO SAT BUT END UP ABOVE
CLIMO SAT NIGHT AND FOR THE REST OF THE PERIOD. HIGHS WILL RUN 5 TO
8 DEGREES ABOVE CLIMO WITH LOWS CLOSER TO 10 DEGREES ABOVE.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...IFR/MVFR CIGS AND VSBYS LIKELY DUE TO PATCHY FOG ALONG
THE COAST AND THE THREAT OF SEVERE WEATHER WITH SHRA/TSRA ACTIVITY
ANTICIPATED THIS EVENING THROUGH THURSDAY MORNING. EXPECT
CONDITIONS TO IMPROVE TO VFR TOWARDS END OF VALID PERIOD.
CURRENT RADAR DEPICTS A LINE OF SHRA/TSRA WEST OF THE
INLAND TERMINALS. ANTICIPATE SHRA/TSRA TO MOVE INTO KFLO/KLBT WITHIN
THE NEXT FEW HOURS...CONTINUING EASTWARD THROUGH THE EARLY OVERNIGHT
HOURS INTO THE COASTAL SITES. AGAIN TO RE-ITERATE...THERE REMAINS A
THREAT OF ISOLATED SEVERE WEATHER WITH THIS CONVECTION. THIS LINE OF
CONVECTION HAS A HISTORY OF PRODUCING STRONG WINDS...THUS HAVE
INCLUDED GUSTS UP TO 40KTS POSSIBLE AT INLAND TERMINALS. CONFIDENCE
IS A BIT LOWERED ON STRENGTH THE ACTIVITY WILL HAVE BY THE TIME IT
REACHES THE COASTAL TERMINALS...THUS HAVE NOT FORECASTED HIGHER
GUSTS ATTM. ONCE THIS LINE OF THUNDERSTORMS MOVES THROUGH...CURRENT
RADAR DEPICTS SHRA/TSRA ALREADY RE-DEVELOPING ALONG THE COLD FRONT.
CONFIDENCE IS LOW WHETHER THIS WILL HOLD TOGETHER BY THE TIME IT
REACHES THE TERMINALS...BUT IN AGREEMENT WITH CURRENT
GUIDANCE...HAVE KEPT IN CURRENT FORECAST. THROUGH THURSDAY
MORNING...WINDS WILL REMAIN SOUTH-SOUTHWEST GENERALLY 8-12KTS.
CURRENT FCST SOUNDINGS AND TIME-SECTION HEIGHTS SEEM TO KEEP IFR
CIGS THROUGH THURSDAY AFTERNOON...BUT ANTICIPATE CONDITIONS TO
IMPROVE BEHIND THE COLD FRONT. WINDS WILL SHIFT FROM SOUTHWEST TO
NORTH-NORTHWEST WITH THE FROPA...WITH GUSTY WINDS UP TO NEAR 25KTS
POSSIBLE ACROSS THE ENTIRE AREA.
EXTENDED OUTLOOK...EXPECT VFR FRIDAY AND SATURDAY...WITH LOWERED
CONFIDENCE FOR POTENTIAL IFR FOG/STRATUS SUNDAY AND MONDAY MORNINGS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 815 PM WEDNESDAY...CONTINUE SCA. AND CONTINUE THE DENSE FOG
ADVISORY ACROSS THE WATERS TIL 10 PM. LATEST WINDS ACROSS THE WATERS
STILL NOT CONDUCIVE TO ERADICATE THE SEA FOG THREAT OR ATLEAST
DIMINISH THE AREAL COVERAGE. SFC BASED COOL MARINE LAYER MAY BE
THICK ENOUGH TO PREVENT THE STRONGER WINDS REACHING THE OCEAN SFC AS
THE STRONGER STORMS MOVE OFF THE MAINLAND DURING THE NEXT 1-2 HOURS
OFF GEORGETOWN TO HORRY COUNTIES.
PREVIOUS DISCUSSION................................................
AS OF 300 PM WEDNESDAY...TROPICAL MOISTURE MOVING ACROSS CHILLY
NEARSHORE OCEAN WATERS HAS RESULTED IN AREAS OF DENSE SEA FOG TODAY.
THIS SHOULD CONTINUE INTO THE EVENING HOURS WITH VISIBILITIES LESS
THAN ONE MILE AT TIMES. THE WORST VISIBILITIES ARE EXPECTED ACROSS
THE WATERS WITHIN 5-8 MILES OF SHORE WHERE WATER TEMPERATURES AND
AIR TEMPERATURES ARE COOLEST.
OTHERWISE...SOUTHWEST WINDS WILL RAMP UP OVERNIGHT IN ADVANCE OF A
STRONG COLD FRONT MOVING EAST TOWARD THE CAROLINAS. LATEST HIGH-
RESOLUTION MODELS SUGGEST THE FIRST BATCH OF SHOWERS AND STRONG
THUNDERSTORMS COULD REACH THE COASTLINE AROUND 10 PM THIS EVENING...
WITH ADDITIONAL SHOWERS AND STORMS POSSIBLE OVERNIGHT UP UNTIL THE
ACTUAL SURFACE COLD FRONT ARRIVES AFTER DAYBREAK THURSDAY MORNING.
SEAS SHOULD GRADUALLY BUILD TONIGHT WITH THE STRONGER SOUTHWEST
WINDS ARRIVING AHEAD OF THE FRONT...REACHING AS HIGH AS 6-8 FT NEAR
CAPE FEAR LATE TONIGHT. THE STRONGEST WINDS SHOULD REMAIN OUT BEYOND
20 MILES FROM SHORE WHERE WARMER AIR AND WATER TEMPERATURES WILL
SUPPORT DEEPER MIXING...BRINGING THESE WINDS DOWN TO THE OCEAN
SURFACE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...PERIOD BEGINS WITH SOLID SCA CONDITIONS
ACROSS THE COASTAL WATERS AS PINCHED GRADIENT EXISTS AHEAD OF A COLD
FRONT. WINDS THURSDAY WILL QUICKLY VEER FROM SW IN THE MORNING TO
NORTHERLY DURING THE AFTN BEHIND THE COLD FRONT. SPEEDS WILL
INCREASE AS WELL...BECOMING SUSTAINED AT NEARLY 25 KTS UNTIL
THURSDAY NIGHT...HELPING TO GENERATE SEAS OF 5-7 FT. CHALLENGE THEN
BECOMES DETERMINING EXACTLY WHEN CONDITIONS WILL DROP BELOW SCA
THRESHOLDS. ALTHOUGH GRADIENT WILL REMAIN PINCHED AS HIGH PRESSURE
SLIDES TOWARDS THE AREA...EXPECT IT WILL SLACKEN ENOUGH TO DROP
WINDS TO 15-20 KTS AND SEAS TO 4-5 FT BY FRIDAY MORNING...SO HAVE
LEFT CURRENT SCA AS-IS. WINDS VEER TO THE NE FRIDAY NIGHT AND EASE
FURTHER...REDUCING SEAS TO 2-4 FT BY THE END OF THE PERIOD.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM WEDNESDAY...LIGHT NORTHEAST FLOW WILL BE QUICK TO VEER
TO SOUTHEASTERLY AS WEAK COASTAL TROUGH DEVELOPS. REMAINS OF THE
TROUGH PUSH INLAND SAT NIGHT INTO SUN AND HIGH PRESSURE RETURNS.
WEAK GRADIENT WILL REMAIN IN PLACE THROUGH THE END OF THE PERIOD
WITH SOUTH TO SOUTHWEST FLOW AROUND 10 KT. COLD FRONT MAY DROP IN
FROM THE NORTH AT THE END OF THE PERIOD...THOUGH TIMING IS STILL IN
QUESTION. SEAS WILL RUN 2 TO 4 FT SAT DROPPING TO 2 TO 3 FT SUN AND
MON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST THURSDAY NIGHT FOR
AMZ250-252-254-256.
&&
$$
SYNOPSIS...TRA/JDW
NEAR TERM...TRA/DCH
SHORT TERM...JDW
LONG TERM...III
AVIATION...SGL
MARINE...ALL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
658 PM EST WED NOV 16 2011
.SYNOPSIS...
A COLD FRONT OVER THE TENNESSEE VALLEY WILL SLIDE EASTWARD BRINGING
SHOWERS AND A CHANCE OF THUNDERSTORMS...INCLUDING SEVERE
WEATHER...TONIGHT THROUGH THURSDAY MORNING. MUCH COOLER AND DRIER
AIR WILL FOLLOW LATE THURSDAY AND FRIDAY. HIGH PRESSURE WILL MOVE
OVERHEAD WITH TEMPERATURES MODERATING DURING THE WEEKEND. A SECOND
FRONT WILL DROP SOUTH THROUGH THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 300 PM WEDNESDAY...TROPICAL WARMTH AND HUMIDITY WILL COME TO A
CRASHING HALT LATE TONIGHT AS A STRONG COLD FRONT ARRIVES FROM THE
WEST. THE TRANSITION FROM A TROPICAL TO AN ARCTIC AIRMASS WILL NOT
BE AN EASY ONE...AND SEVERE THUNDERSTORMS APPEAR POSSIBLE ACROSS THE
EASTERN CAROLINAS TONIGHT.
INSTABILITY PARAMETERS ARE IMPRESSIVE FOR A COOL-SEASON EVENT.
ALTHOUGH SURFACE CAPE FALLS AWAY TO A FEW HUNDRED J/KG AFTER DARK
WITH 75-100 J/KG OF INHIBITION TO OVERCOME...STARTING TO LIFT A
PARCEL FROM AROUND 925 MB YIELDS 600-1500 J/KG OF UNINHIBITED CAPE
AIDED BY REASONABLY STEEP MID AND UPPER LEVEL LAPSE RATES. UNLIKE
OUR TYPICAL WINTERTIME "SEVERE SHOWER" SCENARIOS THERE COULD
ACTUALLY BE DEEP (40+ KFT) CONVECTION TONIGHT. WIND SHEAR PARAMETERS
ARE ALSO IMPRESSIVE: 50-60 KT OF 0-6 KM BULK SHEAR...200-300 M^2/S^2
0-3 KM HELICITY...AND 50 KT WIND SPEEDS WITHIN 2500 FEET OF THE
GROUND ALL POINT TOWARD ORGANIZED STORMS...PERHAPS EVEN
SUPERCELLS...WITH THE POTENTIAL FOR WIND DAMAGE AND TORNADOES.
SYNOPTICALLY A 300 MB JET STREAK WILL MOVE EAST THROUGH THE
MID-ATLANTIC STATES TONIGHT. THIS WILL PLACE THE EASTERN CAROLINAS
WITHIN THE RIGHT-ENTRANCE REGION OF THE JET STREAK AIDING IN
DEEP-LAYER LIFT. TIMING-WISE...THE LAST THREE RUNS (15-16-17Z) OF
THE HRRR RAPID UPDATE MODEL ALL PLACE THE LEADING EDGE OF THE SQUALL
LINE IN WESTERN DARLINGTON COUNTY AT 7 PM...MOVING INTO FLORENCE...
DILLON AND LUMBERTON BY 8 PM...AND TO THE COAST BETWEEN 10 PM AND
MIDNIGHT. OUR HIGHEST POPS (80-90%) EXTEND FROM FLORENCE...MARION
AND MYRTLE BEACH NORTHWARD THROUGH SOUTHEASTERN NORTH CAROLINA.
LOWER POPS (50-60%) ARE FORECAST SOUTH INTO THE GEORGETOWN AREA
WHERE THIS FIRST BATCH OF CONVECTION MAY BE TOO FAR NORTH FOR
IMPACTS. ADDITIONAL SHOWERS AND POSSIBLY THUNDERSTORMS MAY DEVELOP
BEHIND THIS FIRST BATCH...ASSOCIATED WITH SUBTLE UPPER DISTURBANCES
WORKING ON RESIDUAL ELEVATED INSTABILITY. THIS SECOND BATCH OF
CONVECTIVE ACTIVITY COULD CONTINUE UP UNTIL THE TIME OF THE FRONTAL
PASSAGE AROUND DAYBREAK THURSDAY.
LOW TEMPERATURES TONIGHT WILL BE TRICKY WITH THE SURFACE COLD FRONT
LIKELY ARRIVING AROUND 12Z. WE ARE FORECASTING MID 60S ON THE COAST
AND 59-63 INLAND...HOWEVER THERE IS SIGNIFICANT BUST POTENTIAL IN
EITHER DIRECTION IF THE FRONT IS ONLY A COUPLE HOURS FASTER OR SLOWER
THAN IS CURRENTLY FORECAST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...CONCERN DURING THE PERIOD REVOLVES AROUND
COLD FRONTAL PASSAGE AND ASSOCIATED CONVECTION EARLY
THURSDAY...FOLLOWED BY A DRASTIC DROP IN TEMPERATURES WHICH WILL
MAKE IT FEEL ONCE AGAIN LIKE EARLY WINTER.
STRONG COLD FRONT WILL BE JUST INSIDE WESTERN EDGE OF THE CWA
THURSDAY MORNING AND RAPIDLY MOVING EAST. THE UNCERTAINTY WITH
STRENGTH OF CONVECTION REVOLVES AROUND THE FACT THAT FROPA IS
OCCURRING AT A NON-IDEAL TIME WITH RESPECT TO INSTABILITY.
HOWEVER...PARAMETERS DO SUGGEST THAT CONVECTION WILL BE ONGOING AT
THE BEGINNING OF THE PERIOD...ESPECIALLY ACROSS THE EASTERN ZONES.
RIDGE OF LOW LEVEL THETA-E AIR REMAINS IN PLACE THROUGH THURSDAY
MORNING ALONG WITH STEEP MID LEVEL LAPSE RATES AND PWATS NEAR 1.5
INCHES. ADDITIONALLY...SOME PVA NEAR A VORT LOBE TRAILING THROUGH
THE EASTERN CAROLINAS...LOCALLY ENHANCED DIFFLUENCE IN THE RIGHT
ENTRANCE REGION OF AN EXITING UPPER JET...AND THE COLD FRONT ITSELF
WILL HELP FORCE SOME LIFT AND KEEP CONVECTION GOING THROUGH LATE
MORNING. 12 HOUR SREF PRECIP PROBS DO NOT DROP BELOW 50 PERCENT
UNTIL AFTER 03Z FRIDAY...SO ALTHOUGH THE SEVERE THREAT AFTER SUNRISE
THURSDAY APPEARS LIMITED WILL KEEP TSTM MENTION THROUGH LATE MORNING
ALONG THE COAST...WITH SOME LIGHT RAIN POSSIBLE UNTIL EARLY AFTN.
FROPA OCCURS ACROSS THE ENTIRE CWA BY THE AFTN BRINGING AN END TO
PRECIP THROUGH THE REMAINDER OF THE SHORT TERM. DRYING WILL OCCUR
BEHIND FRONT AS HIGH PRESSURE BUILDS INTO THE REGION...BUT POST
FRONTAL CLOUD COVER/STRATUS WILL EXIST THROUGH MUCH OF THURSDAY
BEFORE CLEARING ON FRIDAY.
THE HIGHEST TEMPS OF THE PERIOD WILL OCCUR THURSDAY MORNING ALONG
AND AHEAD OF THE FRONT...DROPPING RAPIDLY IN THE AFTN AS STRONG CAA
DEVELOPS. LARGE BUST POTENTIAL ON MAX TEMPS THURSDAY DEPENDING ON
EXACT TIMING OF FROPA...BUT EXPECT TEMPS AROUND 60 INLAND...MID 60S
AT THE COAST AT DAYBREAK THURSDAY...THEN FALLING THROUGH THE DAY.
MEX/MAV IN AGREEMENT WITH MAX TEMPS FRIDAY IN THE MID 50S...BUT
GUIDANCE HAS A TENDENCY TO OVER FORECAST HIGHS THE DAY AFTER A STRONG
FROPA. WILL TREND MAXES DOWN TO THE LOW/MID 50S...BUT NOTE THIS MAY
STILL BE TOO WARM. MINS EACH NIGHT WILL BE IN THE MID 30S AT THE
COAST...AROUND 30 IN THE COLDER SPOTS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...WEAK RIDGING ALOFT WILL BECOME SUPPRESSED LATE
IN THE PERIOD AS 5H FLOW BECOMES MORE ZONAL. MUCH OF THE PERIOD WILL
BE DOMINATED BY ELONGATED SURFACE HIGH WITH A WEAK COASTAL TROF
DEVELOPING SAT INTO SUN. COASTAL TROF LOOKS PRETTY WEAK SO DO NOT
THINK PRECIP WILL NOT BE AN ISSUE. BACKDOOR COLD FRONT STALLED NORTH
OF THE AREA MON WILL PUSH SOUTH ACROSS THE AREA TUE. NOT MUCH
FORCING ALONG THE FRONT AS IT HEADS SOUTH. FROPA WILL BE MARKED BY
AIR MASS CHANGE BUT VERY LITTLE IF ANY PRECIP. WEAK ISENTROPIC LIFT
LATE IN THE PERIOD AS MID LEVEL RIDGE SHIFTS EAST WILL PROVIDE THE
BEST CHANCE FOR PRECIP DURING THE PERIOD. HOWEVER...GIVEN THE
UNCERTAINTY WITH RESPECT TO THE EVENT PLAN TO CARRY SILENT POP FOR
NOW. TEMPERATURES WILL START OUT NEAR CLIMO SAT BUT END UP ABOVE
CLIMO SAT NIGHT AND FOR THE REST OF THE PERIOD. HIGHS WILL RUN 5 TO
8 DEGREES ABOVE CLIMO WITH LOWS CLOSER TO 10 DEGREES ABOVE.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...IFR/MVFR CIGS AND VSBYS LIKELY DUE TO PATCHY FOG ALONG
THE COAST AND THE THREAT OF SEVERE WEATHER WITH SHRA/TSRA ACTIVITY
ANTICIPATED THIS EVENING THROUGH THURSDAY MORNING. EXPECT
CONDITIONS TO IMPROVE TO VFR TOWARDS END OF VALID PERIOD.
CURRENT RADAR DEPICTS A LINE OF SHRA/TSRA WEST OF THE
INLAND TERMINALS. ANTICIPATE SHRA/TSRA TO MOVE INTO KFLO/KLBT WITHIN
THE NEXT FEW HOURS...CONTINUING EASTWARD THROUGH THE EARLY OVERNIGHT
HOURS INTO THE COASTAL SITES. AGAIN TO RE-ITERATE...THERE REMAINS A
THREAT OF ISOLATED SEVERE WEATHER WITH THIS CONVECTION. THIS LINE OF
CONVECTION HAS A HISTORY OF PRODUCING STRONG WINDS...THUS HAVE
INCLUDED GUSTS UP TO 40KTS POSSIBLE AT INLAND TERMINALS. CONFIDENCE
IS A BIT LOWERED ON STRENGTH THE ACTIVITY WILL HAVE BY THE TIME IT
REACHES THE COASTAL TERMINALS...THUS HAVE NOT FORECASTED HIGHER
GUSTS ATTM. ONCE THIS LINE OF THUNDERSTORMS MOVES THROUGH...CURRENT
RADAR DEPICTS SHRA/TSRA ALREADY RE-DEVELOPING ALONG THE COLD FRONT.
CONFIDENCE IS LOW WHETHER THIS WILL HOLD TOGETHER BY THE TIME IT
REACHES THE TERMINALS...BUT IN AGREEMENT WITH CURRENT
GUIDANCE...HAVE KEPT IN CURRENT FORECAST. THROUGH THURSDAY
MORNING...WINDS WILL REMAIN SOUTH-SOUTHWEST GENERALLY 8-12KTS.
CURRENT FCST SOUNDINGS AND TIME-SECTION HEIGHTS SEEM TO KEEP IFR
CIGS THROUGH THURSDAY AFTERNOON...BUT ANTICIPATE CONDITIONS TO IMPROVE BEHIND
THE COLD FRONT. WINDS WILL SHIFT FROM SOUTHWEST TO NORTH-NORTHWEST
WITH THE FROPA...WITH GUSTY WINDS UP TO NEAR 25KTS POSSIBLE ACROSS
THE ENTIRE AREA.
EXTENDED OUTLOOK...EXPECT VFR FRIDAY AND SATURDAY...WITH LOWERED
CONFIDENCE FOR POTENTIAL IFR FOG/STRATUS SUNDAY AND MONDAY MORNINGS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM WEDNESDAY...TROPICAL MOISTURE MOVING ACROSS CHILLY
NEARSHORE OCEAN WATERS HAS RESULTED IN AREAS OF DENSE SEA FOG TODAY.
THIS SHOULD CONTINUE INTO THE EVENING HOURS WITH VISIBILITIES LESS
THAN ONE MILE AT TIMES. THE WORST VISIBILITIES ARE EXPECTED ACROSS
THE WATERS WITHIN 5-8 MILES OF SHORE WHERE WATER TEMPERATURES AND
AIR TEMPERATURES ARE COOLEST.
OTHERWISE...SOUTHWEST WINDS WILL RAMP UP OVERNIGHT IN ADVANCE OF A
STRONG COLD FRONT MOVING EAST TOWARD THE CAROLINAS. LATEST HIGH-
RESOLUTION MODELS SUGGEST THE FIRST BATCH OF SHOWERS AND STRONG
THUNDERSTORMS COULD REACH THE COASTLINE AROUND 10 PM THIS EVENING...
WITH ADDITIONAL SHOWERS AND STORMS POSSIBLE OVERNIGHT UP UNTIL THE
ACTUAL SURFACE COLD FRONT ARRIVES AFTER DAYBREAK THURSDAY MORNING.
SEAS SHOULD GRADUALLY BUILD TONIGHT WITH THE STRONGER SOUTHWEST
WINDS ARRIVING AHEAD OF THE FRONT...REACHING AS HIGH AS 6-8 FT NEAR
CAPE FEAR LATE TONIGHT. THE STRONGEST WINDS SHOULD REMAIN OUT BEYOND
20 MILES FROM SHORE WHERE WARMER AIR AND WATER TEMPERATURES WILL
SUPPORT DEEPER MIXING...BRINGING THESE WINDS DOWN TO THE OCEAN
SURFACE.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...PERIOD BEGINS WITH SOLID SCA CONDITIONS
ACROSS THE COASTAL WATERS AS PINCHED GRADIENT EXISTS AHEAD OF A COLD
FRONT. WINDS THURSDAY WILL QUICKLY VEER FROM SW IN THE MORNING TO
NORTHERLY DURING THE AFTN BEHIND THE COLD FRONT. SPEEDS WILL
INCREASE AS WELL...BECOMING SUSTAINED AT NEARLY 25 KTS UNTIL
THURSDAY NIGHT...HELPING TO GENERATE SEAS OF 5-7 FT. CHALLENGE THEN
BECOMES DETERMINING EXACTLY WHEN CONDITIONS WILL DROP BELOW SCA
THRESHOLDS. ALTHOUGH GRADIENT WILL REMAIN PINCHED AS HIGH PRESSURE
SLIDES TOWARDS THE AREA...EXPECT IT WILL SLACKEN ENOUGH TO DROP
WINDS TO 15-20 KTS AND SEAS TO 4-5 FT BY FRIDAY MORNING...SO HAVE
LEFT CURRENT SCA AS-IS. WINDS VEER TO THE NE FRIDAY NIGHT AND EASE
FURTHER...REDUCING SEAS TO 2-4 FT BY THE END OF THE PERIOD.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM WEDNESDAY...LIGHT NORTHEAST FLOW WILL BE QUICK TO VEER TO
SOUTHEASTERLY AS WEAK COASTAL TROUGH DEVELOPS. REMAINS OF THE
TROUGH PUSH INLAND SAT NIGHT INTO SUN AND HIGH PRESSURE RETURNS.
WEAK GRADIENT WILL REMAIN IN PLACE THROUGH THE END OF THE PERIOD
WITH SOUTH TO SOUTHWEST FLOW AROUND 10 KT. COLD FRONT MAY DROP IN
FROM THE NORTH AT THE END OF THE PERIOD...THOUGH TIMING IS STILL IN
QUESTION. SEAS WILL RUN 2 TO 4 FT SAT DROPPING TO 2 TO 3 FT SUN
AND MON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST THURSDAY NIGHT FOR
AMZ250-252-254-256.
&&
$$
SYNOPSIS...TRA/JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...III
AVIATION...SGL
MARINE...ALL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
758 PM EST WED NOV 16 2011
.SYNOPSIS...
A COMPLICATED FRONTAL SYSTEM WILL FINALLY BE MOVING TO THE EAST
TONIGHT AND COLD AIR WILL RETURN FOR A COUPLE OF DAYS. MINOR LAKE
EFFECT SNOW IS EXPECTED IN THE SNOW BELT...THEN HIGH PRESSURE WILL
SETTLE IN FOR THE WEEKEND. THE HIGH WILL SET UP ALONG THE EAST
COAST BY EARLY NEXT WEEK. A WET BUT MILD PATTERN WILL THEN RETURN.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WESTERN EDGE OF THE STRATIFORM RAIN SHIELD WAS SLIDING EAST AT
AROUND 35 KTS...ACROSS CENTRAL PENN AND THE SUSQUEHANNA`S WEST
BRANCH VALLEY. ADDITIONAL RAINFALL WILL AVERAGE SEVERAL HUNDREDTHS
OF AN INCH OR LESS ACROSS THE CENTRAL ZONES...WITH ANOTHER 0.10 OF
AN INCH OR SO TO THE EAST OF A LINE FROM KSEG TO KTHV.
AT 23Z...A SFC COLD FRONT EXTENDED FROM JUST WEST OF KJFK...SSW TO
KPHL AND KROA. 21Z HRRR AND 18Z NAM SHOW THE RAIN ENDING ACROSS OUR
FAR SERN ZONES AROUND 05-06Z...WITH JUST SOME SPRINKLES /OR LIGHT
WRN MTN SNOW SHOWERS/ OCCURRING FOR THE REST OF THE OVERNIGHT AS
DRIER AND COOLER AIR ADVECTS STEADILY SE.
COLD AIR WON`T BECOME DEEP ENOUGH TO SUPPORT SIGNIFICANT SNOW
SHOWERS ACROSS THE NW MTNS UNTIL THE MIDDAY TO AFTERNOON HOURS ON
THURSDAY. MORE ON THIS BELOW.
TEMPS DROP BELOW FREEZING IN THE NW JUST AFTER MIDNIGHT. CLOUDS
COULD HANG ON A LONG TIME IN THE WEST...THOUGH...AS WRLY UPSLOPE
FLOW PRODUCES LIFT.
DO NOT EXPECT ANY MORE THAN A DUSTING TONIGHT WITH LITTLE MOISTURE
AND SUBSIDENCE BATTLING THE LLVL UPSLOPE. MINS SHOULD HOLD IN THE
40S IN THE SE HALF OF THE AREA.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THE FORECAST PROBLEM IS WHETHER A SECONDARY WAVE ON THE OLD FRONT
DEVELOPS SOON ENOUGH AND CLOSE ENOUGH TO THE LOCAL AREA /BUT TO
THE SOUTH/ TO PRODUCE LIGHT PCPN BACK INTO THE COOLING AIR OVER
THE REGION...ESP THE SE. THE WAVE HAS BEEN HINTED AT FOR A FEW
DAYS NOW...SO CONFIDENCE HAS INCREASED SLIGHTLY...BUT THE CUTOFF
OF ANY PRECIP LOOKS RATHER SHARP. IT LOOKS LIKE MOST OF THE
POSSIBLE PCPN WOULD STAY TO THE S/E OF THE AREA BUT MAKES A CLOSE
PASS. BUFKIT SOUNDINGS FROM NAM DO LOOK PLENTY COLD FOR
SNOW...BUT IT WOULD BE FALLING INTO ABOVE-FREEZING AIR AND DURING
THE DAYLIGHT HOURS. WILL CALL IT A CHC OF RAIN/SNOW SHOWERS FOR
NOW IN THE FAR LWR SUSQ AS IT IS WORTH A MENTION AT THIS POINT.
TEMPS HARDLY MOVE ON THURS UNDER COLD ADVECTION.
AN EASIER PART TO THE FCST IN THE SHORT TERM IS THAT WE WILL
DOUBTLESSLY SEE LAKE EFFECT CLOUDS/FLURRIES IN THE WEST...AND
ACCUMS IN THE SNOW BELT OF WARREN CO. POTTER AND MCKEAN COULD ALSO
PICK UP AN INCH OR SO THURSDAY INTO THURS NIGHT. THE AXIS OF THE
UPPER TROUGH CROSSES LAKE ERIE MID-DAY THURSDAY AND SHOULD DRIVE
THE HEAVIEST SNOWS INLAND DURING THE LATE DAY AND INTO THE
OVERNIGHT. DURATION OF THE BEST BANDS WOULD PROBABLY BE ONLY UNTIL
FRIDAY MORNING...AS 8H THERMAL TROUGH OF -12C AIR PASSES BY 12Z
FRI. LOCAL PROGRAM GIVES BAND OF AROUND 80 MI EVEN WITH THE
FAVORABLE 280-290 FETCH AND DEEP 10KFT INVERSION. WIND SPEEDS ARE
ONLY 30KTS...BUT ARE WELL-ALIGNED VERTICALLY. STORM TOTALS MIGHT
GET INTO THE 3-4 INCH RANGE OVER 18-20 HRS. THIS IS NOT QUITE
WORTH AN ADVY YET...ESP SINCE IT IS A LATE 2ND/3RD PD EVENT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
UPPER TROF EXITING THE EASTERN U.S. AT THE START OF THE PERIOD WILL
TRANSITION TO BROAD SOUTHWESTERLY FLOW WHICH IS THEN FORECAST TO
DOMINATE MUCH OF THE LONG TERM PERIOD. FLOW IS FORECAST TO TURN
MORE WESTERLY BY THE END OF THE PERIOD AS ENERGY OVER THE WESTERN
U.S. WORKS ITS WAY EAST.
AS THE UPPER TROUGH BUILDS OVER THE WESTERN US LATER THIS
WEEK...THE SOUTHEASTERN RIDGE SHOULD PUSH WARMER AIR INTO OUR
REGION SATURDAY. THE 850 HPA TEMPERATURES ARE PREDICTED TO BE 1SD
ABOVE NORMAL LATE SATURDAY ACROSS THE NW PART OF THE STATE...AND
AREA- WIDE ON SUNDAY. ANOTHER COLD FRONT APPROACHES WITH THE NEXT
CHC FOR SHOWERS LATER SUNDAY INTO MONDAY. THIS FRONT IS FORECAST
TO STALL OVER THE MID ATLANTIC REGION...WITH THE POTENTIAL FOR
WAVES OF LOW PRESSURE TO BRING MORE PCPN INTO THE REGION NEXT MONDAY
INTO TUE...BUT THE DETAILS AT THIS POINT ARE ANYTHING BUT CLEAR.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
COLD FRONT EXITING TO THE EAST THIS EVENING...WILL TAKE REMAINING
RAIN BAND ALONG WITH IT OVER THE NEXT FEW HOURS AS DRIER AIR
UNDERCUTS THE MOISTURE. LOW CIGS REMAIN A POSS IN THE SE THROUGH
03Z. HIGHER TERRAIN OF THE WEST WILL SEE BETTER CHANCE FOR
MVFR/IFR CIGS OVER NEXT 24 HOURS...ESPECIALLY KJST THIS EVENING IN
UPSLOPE FLOW. THEN FOCUS TURNS TO KBFD HEADING INTO THU AS FLOW OFF
LAKE ERIE WILL GENERATE LAKE EFFECT IN NW MTNS. REMAINDER OF AREA
ON THU WILL SEE VFR CONDITIONS.
WINDS WILL PICK UP FROM THE W-NW ON THU...WITH SFC WINDS OF 10-20
MPH COMMON WITH GUSTS AROUND 30 MPH. THESE WILL GRADUALLY DIMINISH
THU NIGHT.
OUTLOOK...
FRI-SAT...VFR. NO SIG WX.
SUN...GENERALLY VFR. MVFR POSS LATE.
MON...MVFR TS/SHRA/CIGS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/STEINBUGL
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO
LONG TERM...DEVOIR/GARTNER
AVIATION...DANGELO/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
649 PM EST WED NOV 16 2011
.SYNOPSIS...
A COMPLICATED FRONTAL SYSTEM WILL FINALLY BE MOVING TO THE EAST
TONIGHT AND COLD AIR WILL RETURN FOR A COUPLE OF DAYS. MINOR LAKE
EFFECT SNOW IS EXPECTED IN THE SNOW BELT...THEN HIGH PRESSURE WILL
SETTLE IN FOR THE WEEKEND. THE HIGH WILL SET UP ALONG THE EAST
COAST BY EARLY NEXT WEEK. A WET BUT MILD PATTERN WILL THEN RETURN.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WESTERN EDGE OF THE STRATIFORM RAIN SHIELD WAS SLIDING EAST AT
AROUND 35 KTS...ACROSS CENTRAL PENN AND THE SUSQUEHANNA`S WEST
BRANCH VALLEY. ADDITIONAL RAINFALL WILL AVERAGE SEVERAL HUNDREDTHS
OF AN INCH OR LESS ACROSS THE CENTRAL ZONES...WITH ANOTHER 0.10 OF
AN INCH OR SO TO THE EAST OF A LINE FROM KSEG TO KTHV.
AT 23Z...A SFC COLD FRONT EXTENDED FROM JUST WEST OF KJFK...SSW TO
KPHL AND KROA. 21Z HRRR AND 18Z NAM SHOW THE RAIN ENDING ACROSS OUR
FAR SERN ZONES AROUND 05-06Z...WITH JUST SOME SPRINKLES /OR LIGHT
WRN MTN SNOW SHOWERS/ OCCURRING FOR THE REST OF THE OVERNIGHT AS
DRIER AND COOLER AIR ADVECTS STEADILY SE.
COLD AIR WON`T BECOME DEEP ENOUGH TO SUPPORT SIGNIFICANT SNOW
SHOWERS ACROSS THE NW MTNS UNTIL THE MIDDAY TO AFTERNOON HOURS ON
THURSDAY. MORE ON THIS BELOW.
TEMPS DROP BELOW FREEZING IN THE NW JUST AFTER MIDNIGHT. CLOUDS
COULD HANG ON A LONG TIME IN THE WEST...THOUGH...AS WRLY UPSLOPE
FLOW PRODUCES LIFT.
DO NOT EXPECT ANY MORE THAN A DUSTING TONIGHT WITH LITTLE MOISTURE
AND SUBSIDENCE BATTLING THE LLVL UPSLOPE. MINS SHOULD HOLD IN THE
40S IN THE SE HALF OF THE AREA.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THE FORECAST PROBLEM IS WHETHER A SECONDARY WAVE ON THE OLD FRONT
DEVELOPS SOON ENOUGH AND CLOSE ENOUGH TO THE LOCAL AREA /BUT TO
THE SOUTH/ TO PRODUCE LIGHT PCPN BACK INTO THE COOLING AIR OVER
THE REGION...ESP THE SE. THE WAVE HAS BEEN HINTED AT FOR A FEW
DAYS NOW...SO CONFIDENCE HAS INCREASED SLIGHTLY...BUT THE CUTOFF
OF ANY PRECIP LOOKS RATHER SHARP. IT LOOKS LIKE MOST OF THE
POSSIBLE PCPN WOULD STAY TO THE S/E OF THE AREA BUT MAKES A CLOSE
PASS. BUFKIT SOUNDINGS FROM NAM DO LOOK PLENTY COLD FOR
SNOW...BUT IT WOULD BE FALLING INTO ABOVE-FREEZING AIR AND DURING
THE DAYLIGHT HOURS. WILL CALL IT A CHC OF RAIN/SNOW SHOWERS FOR
NOW IN THE FAR LWR SUSQ AS IT IS WORTH A MENTION AT THIS POINT.
TEMPS HARDLY MOVE ON THURS UNDER COLD ADVECTION.
AN EASIER PART TO THE FCST IN THE SHORT TERM IS THAT WE WILL
DOUBTLESSLY SEE LAKE EFFECT CLOUDS/FLURRIES IN THE WEST...AND
ACCUMS IN THE SNOW BELT OF WARREN CO. POTTER AND MCKEAN COULD ALSO
PICK UP AN INCH OR SO THURSDAY INTO THURS NIGHT. THE AXIS OF THE
UPPER TROUGH CROSSES LAKE ERIE MID-DAY THURSDAY AND SHOULD DRIVE
THE HEAVIEST SNOWS INLAND DURING THE LATE DAY AND INTO THE
OVERNIGHT. DURATION OF THE BEST BANDS WOULD PROBABLY BE ONLY UNTIL
FRIDAY MORNING...AS 8H THERMAL TROUGH OF -12C AIR PASSES BY 12Z
FRI. LOCAL PROGRAM GIVES BAND OF AROUND 80 MI EVEN WITH THE
FAVORABLE 280-290 FETCH AND DEEP 10KFT INVERSION. WIND SPEEDS ARE
ONLY 30KTS...BUT ARE WELL-ALIGNED VERTICALLY. STORM TOTALS MIGHT
GET INTO THE 3-4 INCH RANGE OVER 18-20 HRS. THIS IS NOT QUITE
WORTH AN ADVY YET...ESP SINCE IT IS A LATE 2ND/3RD PD EVENT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
UPPER TROF EXITING THE EASTERN U.S. AT THE START OF THE PERIOD WILL
TRANSITION TO BROAD SOUTHWESTERLY FLOW WHICH IS THEN FORECAST TO
DOMINATE MUCH OF THE LONG TERM PERIOD. FLOW IS FORECAST TO TURN
MORE WESTERLY BY THE END OF THE PERIOD AS ENERGY OVER THE WESTERN
U.S. WORKS ITS WAY EAST.
AS THE UPPER TROUGH BUILDS OVER THE WESTERN US LATER THIS
WEEK...THE SOUTHEASTERN RIDGE SHOULD PUSH WARMER AIR INTO OUR
REGION SATURDAY. THE 850 HPA TEMPERATURES ARE PREDICTED TO BE 1SD
ABOVE NORMAL LATE SATURDAY ACROSS THE NW PART OF THE STATE...AND
AREA- WIDE ON SUNDAY. ANOTHER COLD FRONT APPROACHES WITH THE NEXT
CHC FOR SHOWERS LATER SUNDAY INTO MONDAY. THIS FRONT IS FORECAST
TO STALL OVER THE MID ATLANTIC REGION...WITH THE POTENTIAL FOR
WAVES OF LOW PRESSURE TO BRING MORE PCPN INTO THE REGION NEXT MONDAY
INTO TUE...BUT THE DETAILS AT THIS POINT ARE ANYTHING BUT CLEAR.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
LOW CIGS STARTING TO LIFT AS THE COLDER AND DRIER AIR UNDERCUTS THE
MOISTURE WHICH IS GETTING CUT OFF FROM THE GOMEX ALREADY.
IMPROVEMENT MAY BE SLOW IN KJST WITH WINDS WNW IN A GOOD UPSLOPE
ORIENTATION. SHSN MAY START IN KJST TONIGHT...BUT WILL KEEP FCST
BETTER THAN VFR FOR NOW. RAIN SHIELD SHOULD GRADUALLY SHRINK AND
SLIDE TO THE EAST PER TRENDS IN RADAR MOSAIC AND MESO MDLS. SLOW
MOVEMENT TO THE SFC TROUGH TO THE SE WILL KEEP LIGHT RAIN GOING
FOR MOST OF THE EVENING IN THE SE. LITTLE/NO PRECIP EXPECTED
OVERNIGHT...BUT A SECONDARY WAVE MAY DEVELOP TONIGHT TO OUR SOUTH
AND THROW SOME COLDER PRECIP BACK IN FROM THE SE. LOW POSS AT THIS
POINT...AND AT THE OUTER REACHES OF THIS 18Z 24HR TAF PD...BUT
SOMETHING TO WATCH FOR ON THURS. UPSLOPE IN THE WEST AND OFF LAKE
ERIE WILL GENERATE LAKE EFFECT THURS AFTN INTO FRI AM VCTY KBFD.
OUTLOOK...
FRI-SAT...VFR. NO SIG WX.
SUN...GENERALLY VFR. MVFR POSS LATE.
MON...MVFR TS/SHRA/CIGS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/STEINBUGL
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO
LONG TERM...DEVOIR/GARTNER
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
107 PM EST TUE NOV 15 2011
.SYNOPSIS...
AN ELONGATED FRONTAL ZONE AND MOISTURE AXIS STRETCHING FROM TEXAS
NORTHEASTWARD THROUGH THE OHIO VALLEY INTO NEW ENGLAND WILL REMAIN
THE FOCUS FOR LIGHT TO MODERATE RAINFALL AMOUNTS THROUGH
TONIGHT...MAINLY OVER THE SOUTHERN HALF OF THE COMMONWEALTH.
SEVERAL WAVES OF LOW PRESSURE RIDE ALONG THE FRONT THROUGH THE
TENNESSEE VALLEY INTO THE MID ATLANTIC THROUGH THURSDAY. HIGH
PRESSURE BUILDING EASTWARD FROM THE PLAINS WILL RETURN FAIR
WEATHER TO THE REGION FRIDAY INTO SATURDAY. UNSEASONABLY MILD
TEMPERATURES TODAY WILL COOL OFF TO BELOW NORMALS FOR THURSDAY
AND FRIDAY...BUT WARMER WEATHER SHOULD RETURN FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
STEADY BUT VERY LIGHT RAIN NOW DIMINISHING IN COVERAGE THROUGH THE
LAST FEW HOURS. EXPECT THIS TREND TO CONTINUE PER HRRR AND NEWEST
NAM12. RUC EVEN DRIER THAN THESE TWO...BUT WILL HOLD HIGH POPS IN
FOR THE LIGHT PRECIP THRU THE EARLY AFTN. THE RAIN SHOULD SHRIVEL
IN PLACE AND MAY NOT CREATE MORE THAN SPRINKLES IN THE SERN CWA.
THE NRN TIER SHOULD BE DRY...BUT WILL HOLD JUST ISOLD POPS THERE
WITH ECHOES CURRENTLY ON RADAR JUST S OF KBFD.
ANOTHER DAY OF ABOVE NORMAL DAYTIME HIGHS TODAY AS WE ARE ALREADY
ABOVE NORMAL MAXES AT 9 AM. MID 50S NW TO MID 60S SE...ABOUT 10
DEGREES OR SO ABOVE MID-NOVEMBER CLIMATOLOGY.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
THERE SHOULD BE A RELATIVE LULL IN THE PCPN EARLY TONIGHT /APPROX
00-06Z/ WITH POPS INCREASING AFTER MIDNIGHT ESPECIALLY ACRS THE
SOUTHERN TIER. THE AFOREMENTIONED FRONTAL BOUNDARY INITIALLY
DRAPED OVER THE OH RIVER VALLEY WILL SETTLE SEWD INTO VA...AS A
SFC WAVE RIDES NEWD ALONG THE FRONT. THERE ARE SOME DIFFS WITH THE
TRACK OF THE WAVE...BUT OVERALL THERE IS A STRONG CONSENSUS
SUPPORTING CATG POPS IN THE SOUTH IN THE 06-12Z TIME FRAME. MDL
DIAG FROM HPC FAVORS A MORE SUPPRESSED NAM/GFS TRACK VS. THE OTHER
GUIDANCE GIVEN PROGRESSIVE FLOW UPSTREAM AND CONFLUENCE IN THE
AREA WHERE THE SYS IS MOVING INTO. WHILE THERE WILL BE A
RESURGENCE IN PWATS...THE BEST DEEP LAYER MSTR AND H85 MSTR FLUX
IS PROGGED TO STAY S OF THE TURNPIKE. THE SOMEWHAT LIMITED MSTR
AVAILABILITY WILL ONLY SUPPORT A STRIPE OF 0.25-0.50 INCH AMTS OVR
THE SRN TIER...BRINGING THE 24 HOUR TOTAL TO 0.5-1 INCH IN THIS
AREA.
&&
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
A SHARP COLD FRONT WILL DIVE ACROSS THE CENTRAL AND EASTERN GREAT
LAKES ON WEDNESDAY AS A WAVE RIPPLES ALONG THE NEARLY STATIONARY
FRONT DRAPED SOUTH OF THE MASON DIXON LINE. THIS WILL KEEP CLOUDS
AND RAIN CHANCES MOST CONCENTRATED ALONG AND SOUTH OF THE TURNPIKE
NORTHEASTWARD THROUGH EAST CENTRAL PA THROUGH WEDNESDAY EVENING
BEFORE COLDER AIR ARRIVES WEDNESDAY NIGHT AND THURSDAY...BRINGING
A PERIOD OF SNOW SHOWERS OR FLURRIES TO CENTRAL AND WESTERN AREAS.
A LIGHT ACCUMULATION OF SNOW STILL APPEARS LIKELY OVER THE
SNOWBELT AREAS...AS 850 MB TEMPS PLUNGE TO AROUND -8C BY THURSDAY
AFTERNOON AND OVER-LAKE TRAJECTORIES ARE FAVORABLE FOR LAKE BANDING.
TEMPERATURES MODERATE BACK TOWARD NORMAL THURSDAY NIGHT INTO
FRIDAY...AS RETURN FLOW AROUND THE TRANSIENT SOUTHEASTERN
US/WESTERN ATLANTIC RIDGE LIMITS THE SOUTHWARD PENETRATION OF THE
FRONT.
AS THE UPPER TROUGH BUILDS OVER THE WESTERN US LATER THIS
WEEK...THE SOUTHEASTERN RIDGE SHOULD PUSH WARMER AIR INTO OUR
REGION SATURDAY. THE 850 HPA TEMPERATURES ARE PREDICTED TO BE 1SD
ABOVE NORMAL LATE SATURDAY ACROSS THE NW PART OF THE STATE...AND
AREA- WIDE ON SUNDAY. ANOTHER COLD FRONT APPROACHES WITH THE NEXT
CHC FOR SHOWERS LATER SUNDAY INTO MONDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
THE LATEST OBSERVATIONAL DATA INDICATES SIGNIFICANT IMPROVEMENT
AT ALL TAF LOCATIONS. ONLY MVFR IS LEFT AT KBFD AND THEY SHOULD
IMPROVE AS WELL. FOR THE REMAINDER OF TODAY...MAINLY VFR AS CIGS
REMAIN FAIRLY HIGH AND LIGHT RAIN TAPERING TO SCATTERED DRIZZLE.
A SERIES OF FRONTAL WAVES WILL FORM ALONG/EAST OF THE CENTRAL
APPALACHIANS BRINGING MORE UNSETTLED WEATHER TO THE REGION LATER
TONIGHT THRU WED. CONDITIONS WILL BEGIN TO DETERIORATE AROUND 6Z
ACROSS SOUTHERN TERMINALS AND CONTINUE NORTHWARD THROUGH THE
EARLY MORNING. BY 12Z ALL TERMINALS SHOULD EXPERIENCE IFR
CONDITIONS.
NORTHWESTERLY FLOW WILL LIKELY BRING LOW CIGS AND SOME -SHSN INTO
THE WESTERN TAFS ON THURSDAY GIVEN COLDER DOWNWIND LAKE
TRAJECTORIES. ELSEWHERE VFR CONDITIONS SHOULD PREVAIL FROM
THURSDAY INTO THE WEEKEND.
OUTLOOK...
THUR...MVFR-IFR WEST...BCMG VFR EAST. GUSTY NW WINDS.
FRI-SUN...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DANGELO/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...DEVOIR/GARTNER
AVIATION...DANGELO/KREKELER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1002 AM EST TUE NOV 15 2011
.SYNOPSIS...
AN ELONGATED FRONTAL ZONE AND MOISTURE AXIS STRETCHING FROM TEXAS
NORTHEASTWARD THROUGH THE OHIO VALLEY INTO NEW ENGLAND WILL REMAIN
THE FOCUS FOR LIGHT TO MODERATE RAINFALL AMOUNTS THROUGH
TONIGHT...MAINLY OVER THE SOUTHERN HALF OF THE COMMONWEALTH.
SEVERAL WAVES OF LOW PRESSURE RIDE ALONG THE FRONT THROUGH THE
TENNESSEE VALLEY INTO THE MID ATLANTIC THROUGH THURSDAY. HIGH
PRESSURE BUILDING EASTWARD FROM THE PLAINS WILL RETURN FAIR
WEATHER TO THE REGION FRIDAY INTO SATURDAY. UNSEASONABLY MILD
TEMPERATURES TODAY WILL COOL OFF TO BELOW NORMALS FOR THURSDAY
AND FRIDAY...BUT WARMER WEATHER SHOULD RETURN FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
STEADY BUT VERY LIGHT RAIN NOW DIMINISHING IN COVERAGE THROUGH THE
LAST FEW HOURS. EXPECT THIS TREND TO CONTINUE PER HRRR AND NEWEST
NAM12. RUC EVEN DRIER THAN THESE TWO...BUT WILL HOLD HIGH POPS IN
FOR THE LIGHT PRECIP THRU THE EARLY AFTN. THE RAIN SHOULD SHRIVEL
IN PLACE AND MAY NOT CREATE MORE THAN SPRINKLES IN THE SERN CWA.
THE NRN TIER SHOULD BE DRY...BUT WILL HOLD JUST ISOLD POPS THERE
WITH ECHOES CURRENTLY ON RADAR JUST S OF KBFD.
ANOTHER DAY OF ABOVE NORMAL DAYTIME HIGHS TODAY AS WE ARE ALREADY
ABOVE NORMAL MAXES AT 9 AM. MID 50S NW TO MID 60S SE...ABOUT 10
DEGREES OR SO ABOVE MID-NOVEMBER CLIMATOLOGY.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
THERE SHOULD BE A RELATIVE LULL IN THE PCPN EARLY TONIGHT /APPROX
00-06Z/ WITH POPS INCREASING AFTER MIDNIGHT ESPECIALLY ACRS THE
SOUTHERN TIER. THE AFOREMENTIONED FRONTAL BOUNDARY INITIALLY
DRAPED OVER THE OH RIVER VALLEY WILL SETTLE SEWD INTO VA...AS A
SFC WAVE RIDES NEWD ALONG THE FRONT. THERE ARE SOME DIFFS WITH THE
TRACK OF THE WAVE...BUT OVERALL THERE IS A STRONG CONSENSUS
SUPPORTING CATG POPS IN THE SOUTH IN THE 06-12Z TIME FRAME. MDL
DIAG FROM HPC FAVORS A MORE SUPPRESSED NAM/GFS TRACK VS. THE OTHER
GUIDANCE GIVEN PROGRESSIVE FLOW UPSTREAM AND CONFLUENCE IN THE
AREA WHERE THE SYS IS MOVING INTO. WHILE THERE WILL BE A
RESURGENCE IN PWATS...THE BEST DEEP LAYER MSTR AND H85 MSTR FLUX
IS PROGGED TO STAY S OF THE TURNPIKE. THE SOMEWHAT LIMITED MSTR
AVAILABILITY WILL ONLY SUPPORT A STRIPE OF 0.25-0.50 INCH AMTS OVR
THE SRN TIER...BRINGING THE 24 HOUR TOTAL TO 0.5-1 INCH IN THIS
AREA.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A SHARP COLD FRONT WILL DIVE ACROSS THE CENTRAL AND EASTERN GREAT
LAKES ON WEDNESDAY AS A WAVE RIPPLES ALONG THE NEARLY STATIONARY
FRONT DRAPED SOUTH OF THE MASON DIXON LINE. THIS WILL KEEP CLOUDS
AND RAIN CHANCES MOST CONCENTRATED ALONG AND SOUTH OF THE TURNPIKE
NORTHEASTWARD THROUGH EAST CENTRAL PA THROUGH WEDNESDAY EVENING
BEFORE COLDER AIR ARRIVES WEDNESDAY NIGHT AND THURSDAY...BRINGING
A PERIOD OF SNOW SHOWERS OR FLURRIES TO CENTRAL AND WESTERN AREAS.
A LIGHT ACCUMULATION OF SNOW STILL APPEARS LIKELY OVER THE
SNOWBELT AREAS...AS 850 MB TEMPS PLUNGE TO AROUND -8C BY THURSDAY
AFTERNOON AND OVER-LAKE TRAJECTORIES ARE FAVORABLE FOR LAKE BANDING.
TEMPERATURES MODERATE BACK TOWARD NORMAL THURSDAY NIGHT INTO
FRIDAY...AS RETURN FLOW AROUND THE TRANSIENT SOUTHEASTERN
US/WESTERN ATLANTIC RIDGE LIMITS THE SOUTHWARD PENETRATION OF THE
FRONT.
AS THE UPPER TROUGH BUILDS OVER THE WESTERN US LATER THIS
WEEK...THE SOUTHEASTERN RIDGE SHOULD PUSH WARMER AIR INTO OUR
REGION SATURDAY. THE 850 HPA TEMPERATURES ARE PREDICTED TO BE 1SD
ABOVE NORMAL LATE SATURDAY ACROSS THE NW PART OF THE STATE...AND
AREA- WIDE ON SUNDAY. ANOTHER COLD FRONT APPROACHES WITH THE NEXT
CHC FOR SHOWERS LATER SUNDAY INTO MONDAY.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
THE LATEST OBSERVATIONAL DATA INDICATES SIGNIFICANT IMPROVEMENT AT
ALL TAF LOCATIONS. ONLY MVFR IS LEFT AT KIPT. THE PRECIP SHOULD
CONTINUE TO BREAK UP AND BECOME LIGHTER IN PLACE WITH LITTLE N-S
MOVEMENT OF THE ECHOES THIS AFTN.
THE OLD FRONT IS JUST TO THE S OF THE STATE THIS MORNING. A SERIES
OF FRONTAL WAVES WILL FORM ALONG/EAST OF THE CENTRAL APPALACHIANS
BRINGING MORE UNSETTLED WX TO THE REGION LATER TNT THRU WED
/ESPECIALLY THE SRN AIRFIELDS/. NWLY FLOW WILL LKLY BRING LOW CIGS
AND SOME -SHSN INTO THE WESTERN TAFS ON THURSDAY GIVEN COLDER
DOWNWIND LAKE TRAJECTORIES. ELSEWHERE VFR CONDS SHOULD PREVAIL FM
THURSDAY INTO THE WEEKEND.
OUTLOOK...
THUR...MVFR-IFR WEST...BCMG VFR EAST. GUSTY NW WINDS.
FRI-SAT...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DANGELO/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...DEVOIR/GARTNER
AVIATION...DANGELO/STEINBUGL
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1122 PM CST MON NOV 14 2011
.AVIATION...
/06Z TAFS/
CONCERNS...THUNDERSTORM TIMING AND LOW CEILINGS.
SOME WEAK CONVECTION DEVELOPED NEAR FRONTAL BOUNDARY NORTHWEST OF
TAF SITES...BUT MAIN CONVECTION HAS FORMED WITHIN FAVORED AREA
INVOF MNZ-DAL-SLR. WITH MEAGER CAPE VALUES AND MARGINAL MID-LEVEL
LAPSE RATES...SHOWERS WILL LIKELY OUTNUMBER THUNDERSTORMS. THOSE
STORMS THAT OCCUR ARE NOT EXPECTED TO BECOME SEVERE. CELLS WILL
TRAIN...BUT RAINFALL WILL GENERALLY BE UNDER 1/2 INCH PER HOUR AT
TAF SITES. MAINTAINING 06-10Z (MIDNIGHT-4 AM CST) AS PRIMARY
WINDOW FOR THUNDER AT METRO TAF SITES. ADJUSTED WACO TO FOCUS
THUNDER WITHIN 08-13Z (2-7 AM CST) TIME FRAME.
CEILINGS WILL LIKELY DETERIORATE WITH PROLONGED PRECIPITATION...
AND 06Z TAFS WILL SHOW A GRADUAL LOWERING THROUGH DAYBREAK. (HAVE
REMOVED IFR TEMPO FROM TAFACT.) CEILINGS WILL RECOVER TO VFR BY
MIDDAY AS PRECIP AREA MOVES EAST OF THE I-35 CORRIDOR.
25
&&
.UPDATE...
THE LAST SEVERAL RUNS OF THE RUC HAVE KEPT MOST OF THE RAIN
SOUTHEAST OF A BONHAM...WAXAHACHIE...LAMPASAS LINE. THE 00Z RUN
OF THE NAM ALSO KEEPS MOST OF THE RAIN ACROSS THE SOUTHEASTERN
HALF OF NORTH TEXAS. THE WORKSTATION WRF AND HIGH RESOLUTION
RAPID REFRESH...INDICATE BETTER CHANCES FARTHER WEST...GENERALLY
SOUTHEAST OF A SHERMAN TO CISCO LINE. HAVE MADE SOME ADJUSTMENTS
TO THE POPS TONIGHT...PLACING THE BEST CHANCES ALONG A BAND FROM
BONHAM AND PARIS SOUTHWEST TO LAMPASAS AND CAMERON....WITH LOWER
CHANCES TO THE NORTHWEST AND SOUTHEAST.
HAVE LEFT THE POPS AS IS FOR TUESDAY...AS MOST AREAS SOUTHEAST OF
A SHERMAN TO COMANCHE LINE SHOULD SEE SOME RAIN...THOUGH THE
HEAVIER AMOUNTS WILL BE EAST OF A BONHAM...HILLSBORO...LAMPASAS
LINE.
58
&&
.PREV DISCUSSION... /ISSUED 249 PM CST MON NOV 14 2011/
UPPER LEVEL LOW OVER NORTHWEST MEXICO WILL APPROACH WEST TEXAS
TONIGHT AND MOVE EAST-NORTHEAST ACROSS THE STATE TOMORROW. HIGH
CLOUDS HAVE BEEN STREAMING OVERHEAD FOR THE PAST COUPLE OF DAYS
AHEAD OF THIS SYSTEM. LOW CLOUDS SHOULD ALSO ENVELOP THE REGION
TONIGHT THROUGH TOMORROW AS LOW LEVEL MOISTURE CONTINUES TO
INCREASE. SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BEGIN TO
+DEVELOP THIS EVENING AS HEIGHTS FALL AND UVVS BECOME PRONOUNCED IN
ADVANCE OF THE UPPER LOW. FOR THIS EVENING IT APPEARS THAT SHOWERS
AND STORMS WILL BE MAINLY SCATTERED IN NATURE AND BEGIN AROUND
THE 8-10 PM TIME.
MEANWHILE A WEAK SURFACE BOUNDARY NEAR THE RED RIVER WILL UNDERGO
COLD FRONTOGENESIS TONIGHT AS IT SHIFTS SOUTH AND DEVELOPS ACROSS
THE CENTRAL PORTION OF THE REGION. WE EXPECT SHOWER AND THUNDERSTORM
ACTIVITY TO CONTINUE TO INCREASE IN COVERAGE AFTER MIDNIGHT. THE
BEST RAIN CHANCES WILL BE PRIMARILY ALONG AND SOUTH OF A LINE FROM
PARIS TO COMANCHE IN HIGHEST MOISTURE REGION...ROUGHLY NEAR AND
SOUTHEAST OF THE FORECAST LOCATION OF THE SURFACE BOUNDARY.
INSTABILITY WILL BE MARGINAL WITH SB CAPE APPROACHING 1000
J/KG...WHILE DEEP LAYER SHEAR WILL APPROACH 50 KT DURING THE
OVERNIGHT HOURS. THIS SHOULD BE ENOUGH TO ALLOW FOR A FEW SEVERE
THUNDERSTORMS TO DEVELOP WITH HAIL AND DAMAGING WINDS THE MAIN
THREAT LATE TONIGHT AND TOMORROW MORNING. THE BEST CHANCE FOR SEVERE
STORMS WILL LIKELY OCCUR OVER EAST AND SOUTHEAST COUNTIES AFTER
MIDNIGHT THROUGH MIDDAY TUESDAY. CANNOT RULE OUT AN ISOLATED
TORNADO AS 0-3 KM SR HELICITY MAY OCCASIONALLY EXCEED 100 BUT THE
THREAT SHOULD BE RATHER LOW.
THE OTHER CONCERN WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAIN IF
TRAINING STORMS BECOME AN ISSUE. MODEL QPF AND HPC GUIDANCE DO SHOW
SOME POTENTIAL FOR ISOLATED TOTALS ABOVE 3 INCHES OVER THE EASTERN
AND SOUTHEASTERN COUNTIES...MAINLY SOUTH OF INTERSTATE 20. PW
FORECASTS HAVE LIKEWISE INCREASED SOME SO WILL KEEP AN EYE ON THE
FLOOD THREAT AND MONITOR THE EVOLUTION OF THE SYSTEM. FOR NOW IT
LOOKS LIKE 1-2 INCH TOTALS ARE MORE LIKELY OVER THE SOUTHEAST WITH
LOCALIZED HIGHER AMOUNTS. EXPECT OVERALL RAINFALL TOTALS TO
DECREASE AS YOU APPROACH THE RED RIVER WITH THE LOWEST STORM
TOTAL AMOUNTS OVER THE NORTHWESTERN MOST COUNTIES.
ACTIVITY WILL SHIFT EAST OF THE STATE ALONG WITH THE UPPER LEVEL
LOW TOMORROW EVENING AS THE COLD FRONT PUSHES SOUTHEAST THROUGH
THE REGION. COOLER DRIER CONDITIONS ARE FORECAST WEDNESDAY THROUGH
FRIDAY BEHIND THE FRONT. A WARM-UP WILL THEN OCCUR THIS WEEKEND AS
RETURN FLOW BECOMES REESTABLISHED. ANOTHER COLD FRONT MAY BRING A
CHANCE FOR SHOWERS AND THUNDERSTORMS AGAIN LATE IN THE WEEKEND OR
EARLY NEXT WEEK.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 65 73 52 65 41 / 50 60 20 0 0
WACO, TX 65 73 52 69 41 / 60 80 10 0 0
PARIS, TX 65 71 51 62 37 / 70 80 60 10 0
DENTON, TX 63 73 46 64 37 / 40 50 20 0 0
MCKINNEY, TX 64 72 49 63 37 / 50 70 40 5 0
DALLAS, TX 66 72 53 66 41 / 50 70 30 0 0
TERRELL, TX 66 71 53 67 39 / 60 80 40 5 0
CORSICANA, TX 67 72 52 69 42 / 60 80 30 5 0
TEMPLE, TX 66 74 55 72 42 / 60 80 10 0 0
MINERAL WELLS, TX 60 73 45 64 35 / 40 40 10 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25/58
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
328 PM CST TUE NOV 15 2011
.TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE HIGH.
SURFACE LOW PRESSURE TRACKING FROM NORTHERN WI TO LAKE SUPERIOR
WILL DRAG A COLD FRONT ACROSS SOUTHERN WISCONSIN THIS EVENING.
SURFACE WINDS WILL SHIFT FROM SOUTHWEST TO WEST EARLY THIS EVENING
IN MADISON...LATER THIS EVENING IN MILWAUKEE. WINDS WILL THEN VEER
TO THE WNW AFTER MIDNIGHT. TEMPERATURES WILL BE SLOW TO COOL THIS
EVENING...BUT THEN DROP RAPIDLY AFTER MIDNIGHT WITH THE COLD AIR
ADVECTION BEHIND THE SFC TROUGH/FRONT. LOWS EXPECTED IN THE MID TO
UPPER 20S...WARMEST NEAR THE LAKE. 850MB TEMPS WILL BE AROUND -8
TO -10C OVERNIGHT...POSSIBLY THE COLDEST SO FAR THIS SEASON.
WINDS SHOULD DECOUPLE THIS EVENING WITH AN INVERSION SETTING
UP...THEN HAVE A BETTER POTENTIAL TO GUST AFTER MIDNIGHT...BUT
ESPECIALLY EARLY WED MORNING...WITH THE COLD AIR ADVECTION. THE
NAM SNDGS SHOW A STRONGER INVERSION THAN THE RUC AND GFS...BUT
MAKE SENSE. EXPECT WNW WINDS THROUGH THE DAY ON WEDNESDAY...WITH
GUSTS UP TO 25 KNOTS LIKELY...ESPECIALLY IN THE MORNING. THE
PRESSURE GRADIENT WILL SLOWLY RELAX WED AFTERNOON AS HIGH PRESSURE
RIDGES INTO SOUTHERN WI.
.SHORT TERM...WEDNESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE
MEDIUM TO HIGH.
SECONDARY COLD FRONT SHIFTS SOUTHEAST THROUGH THE AREA WEDNESDAY
NIGHT...WITH SOME MORE COLD AIR ADVECTION IN ITS WAKE. PASSING
VORTICITY MAXIMUM FIGHTING SOMEWHAT DRY AIRMASS OVER THE AREA...SO
LEFT OUT MENTION OF FLURRIES. COLDER TEMPERATURES EXPECTED TO
CONTINUE...WITH LOWS IN THE LOWER TO MID 20S PER 925MB
TEMPERATURES OF 5 TO 9 BELOW ZERO.
WARM AIR ADVECTION BEGINS THURSDAY...AND CONTINUES THURSDAY NIGHT
AND FRIDAY ACROSS THE AREA. THURSDAY SHOULD STILL REMAIN
COLD...WITH HIGHS ONLY IN THE MID TO UPPER 30S. TEMPERATURES WILL
WARM THURSDAY NIGHT AND FRIDAY...AS WINDS SHIFT SOUTH/SOUTHWEST
AND BECOME GUSTY WITH A TIGHTENING PRESSURE GRADIENT. HIGHS SHOULD
RISE INTO THE MID TO UPPER 40S FRIDAY...WITH THE FAIRLY DRY
AIRMASS LINGERING WITH CONTINUED WARM AIR ADVECTION.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE
MEDIUM.
STRONG LOW PRESSURE WILL FORM IN THE CENTRAL PLAINS FRIDAY
NIGHT...THEN SHIFT NORTHEAST INTO THE REGION SATURDAY...THEN
NORTHEAST OF THE AREA SATURDAY NIGHT. THE GFS/CANADIAN/00Z ECMWF
DIFFER SOMEWHAT WITH TIMING AND PLACEMENT OF THE LOW. THE CANADIAN
IS QUICKEST NORTHEAST INTO THE AREA...ACROSS CENTRAL WISCONSIN BY
00Z SUNDAY. THE GFS/00Z ECMWF ARE SLOWER AND OVER NORTH
CENTRAL/NORTHEAST IOWA AT 00Z SUNDAY.
ALL MODELS BRING FOCUSED WARM AIR ADVECTION AND FRONTOGENESIS
RESPONSE THROUGH THE REGION SATURDAY...WITH AREA THEN GETTING INTO
THE WARM SECTOR. COLD FRONT THEN SHIFTS EAST THROUGH THE AREA
SATURDAY NIGHT. MAIN SHORTWAVE TROUGH STAYS NORTHWEST OF THE AREA
DURING THIS TIME.
KEPT HIGH END CHANCE POPS FOR SATURDAY...THEN TRENDED DOWNWARD
SATURDAY NIGHT. KEPT SLIGHT CHANCES FOR THUNDER SATURDAY WITHIN
WARM SECTOR AND WEAK INSTABILITY IN LOW LEVELS WITH STRONG
DYNAMICS...AND SATURDAY NIGHT ACROSS THE SOUTHEAST COUNTIES.
COLDER AIR QUICKLY WRAPS INTO THE BACKSIDE OF SYSTEM LATER
SATURDAY NIGHT...SO MENTIONED CHANCES FOR A MIX OF RAIN AND SNOW
SHOWERS IN THE NORTHWEST HALF OF THE AREA. MAY HAVE TO RAISE
POPS IN SUBSEQUENT FORECASTS IF MODELS CONTINUE TO SHOW GENERAL
AGREEMENT WITH THIS SYSTEMS.
MODELS THEN IN FAIR AGREEMENT WITH HIGH PRESSURE MOVING INTO THE
REGION SUNDAY...THEN SLOWLY EAST SOUTHEAST ACROSS THE REGION
THROUGH TUESDAY. THEY ALSO SHOW A SHORTWAVE TROUGH MOVING THROUGH
THE REGION MONDAY...WITH THE GFS ABOUT SIX HOURS SLOWER THAN THE
00Z ECMWF. SOME QUESTION AS TO THE AMOUNT OF MOISTURE AVAILABLE
WITH THIS FEATURE. FOR NOW...WILL MAINTAIN SLIGHT CHANCE POPS FOR
LIGHT RAIN AND SNOW SHOWERS. THE REST OF THIS PERIOD APPEARS TO BE
DRY. COOL TEMPERATURES SHOULD LINGER DURING THIS PERIOD AS WELL.
&&
.AVIATION/00Z TAFS/...
SURFACE LOW PRESSURE WILL TRACK FROM NORTHERN WISCONSIN TO LAKE
SUPERIOR THIS EVENING...AND DRAG A COLD FRONT ACROSS SOUTHERN WI.
VFR CONDITIONS THROUGH THE PERIOD. WINDS WILL GRADUALLY VEER WEST
THIS THIS EVENING...THEN WNW AND INCREASE AFTER MIDNIGHT WITH
COLDER AIR WORKING INTO THE REGION BEHIND THE FRONT.
LOW LEVEL WIND SHEAR EXPECTED AFTER MIDNIGHT AT ALL TAF SITES.
WIND GUSTS WILL INCREASE TOWARD WED MORNING AS THE INVERSION
ERODES AWAY WITH COLD AIR ADVECTION. BRISK DAY ON WED...WITH GUSTS
TO 25 KNOTS POSSIBLE.
&&
.MARINE...
SMALL CRAFT ADVISORY IN EFFECT THROUGH WEDNESDAY AFTERNOON AS LOW
PRESSURE TRACKS FROM NORTHERN WI THROUGH LAKE SUPERIOR AND INTO
ONTARIO. THERE WILL BE A LULL IN THE WINDS THIS EVENING AS THE
SURFACE TROUGH CROSSES LAKE MICHIGAN...THEN WINDS WILL INCREASE
TOWARD WEDNESDAY MORNING AS COLD AIR WORKS INTO THE AREA BEHIND
THE FRONT. WINDS WILL EASE IN THE AFTERNOON...FALLING BELOW SMALL
CRAFT ADVISORY CRITERIA BY EVENING.
SURFACE HIGH PRESSURE WILL BUILD INTO SOUTHERN WI AND LAKE
MICHIGAN ON THURSDAY. THE PRESSURE GRADIENT WILL INCREASE ONCE
AGAIN BETWEEN THE HIGH IN THE SOUTHERN U.S. AND LOW PRESSURE
MOVING THROUGH THE UPPER MIDWEST. SMALL CRAFT ADVY POTENTIAL ONCE
AGAIN ON FRIDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM CST WEDNESDAY FOR LMZ643>646.
&&
$$
TONIGHT/WEDNESDAY AND AVIATION/MARINE...MRC
WEDNESDAY NIGHT THROUGH TUESDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
309 PM CST TUE NOV 15 2011
.SHORT TERM...TODAY THROUGH THURSDAY
309 PM CST TUE NOV 15 2011
FORECAST CONCERNS INCLUDE WIND THIS EVENING...LIGHT SNOW CHANCES
ACROSS THE NORTH TONIGHT...COLDER CYCLONIC FLOW THROUGH
WEDNESDAY...THEN WARMING TREND THURSDAY THROUGH FRIDAY.
ACTIVE FLOW ALOFT DEPICTED BY WATER VAPOR IMAGERY. A POTENT
MID-LEVEL SHORTWAVE TROUGH/PV-ANOMALY WAS MOVING ACROSS MN WITH
RADAR MOSAIC AND SURFACE OBSERVATIONS SHOWING SOME RAIN/SNOW SHOWER
ACTIVITY ASSOCIATED WITH IT. OUR FORECAST AREA HAD A FEW MID CLOUDS
WITH TEMPERATURES IN THE 50S.
15.12Z NCEP MODEL SUITE AND THE 15.09Z SREF SHOWING VERY GOOD
AGREEMENT WITH OVERALL SYNOPTIC PATTERN THROUGH THE SHORT TERM
PERIOD.
FOR TONIGHT...WILL BE WATCHING THAT POTENT MID-LEVEL TROUGH ACROSS
WESTERN MN DAMPENING WITH TIME AS IT SWINGS INTO WESTERN LAKE
SUPERIOR BY LATE THIS EVENING. NAM12 REFLECTIVITY/SCARIFY BOTH SUPPORT
A BAND OF MAINLY SNOW SHOWERS ALONG AN AXIS OF 700-300MB
PV-ADVECTION MARCHING EAST ACROSS NORTHERN WI THIS EVENING. HAVE
INCLUDED 20-30 POPS OF MEASURABLE SNOW NORTH OF HIGHWAY 10 TO
ACCOUNT FOR THIS. WILL HAVE TO KEEP AN EYE ON HOW THINGS MATERIALIZE
ACROSS MINNESOTA AND ADJUST AS NECESSARY. A WEAKER MID-LEVEL WAVE
FOLLOWS CLOSELY ON THE HEELS OF THIS ONE AND THUS HAVE INCLUDED
SMALL POPS ACROSS THE NORTH AFTER MIDNIGHT AS WELL. OTHERWISE...
LOOKING FOR RATHER WINDY CONDITIONS GOING INTO THIS EVENING WITH
DOWNWARD MOMENTUM IN COLD AIR ADVECTION...THEN SUBSIDING SOMEWHAT
AFTER MIDNIGHT AS THE PRESSURE GRADIENT SLACKENS. WILL CONTINUE THE
CURRENT WIND ADVISORY UNTIL 03Z ACROSS PORTIONS OF NORTHEAST
IA/SOUTHEAST MN.
COLD CYCLONIC FLOW LINGERS ACROSS THE AREA ON WEDNESDAY WITH
STEEPENING LOW-LEVEL LAPSE RATES GOING INTO THE AFTERNOON. GOOD
MIXING WILL ALLOW FOR BRISK CONDITIONS ONCE AGAIN WITH GUSTS IN THE
25 TO 30 MPH RANGE. ALSO...STEEPER LAPSE RATES WILL PRODUCE SOME
HIGHER BASED CUMULUS AND POSSIBLY SOME FLURRIES BY LATER IN THE
AFTERNOON. OTHERWISE...WITH 925MB TEMPERATURES ONLY IN THE -2 TO -5C
ANGE...EXPECTING HIGHS ONLY IN THE MID 30S TO A FEW LOWER 40S ACROSS
THE SOUTH.
THE NAM SHOWS ANOTHER MID-LEVEL SHORTWAVE TROUGH ROTATING SOUTHEAST
ACROSS THE AREA FOR WEDNESDAY EVENING WITH FAIRLY STRONG BAND OF
700-300MB PV-ADVECTION. BUFKIT SOUNDING ALSO SHOW SOME COLUMN
SATURATION WITH THIS FORCING...BY MAINTAIN A FAIRLY DRY SUB-CLOUD
LAYER NEAR THE SURFACE. AS SUCH...HAVE INCLUDED SNOW FLURRY MENTION
INTO THE EVENING HOUR AS THIS WAVE ROTATES THROUGH. 925MB
TEMPERATURES DROP INTO THE -7 TO -10C RANGE OVERNIGHT FOR A PRETTY
GOOD DROP-OFF IN TEMPERATURES. HOWEVER...WILL PROBABLY NOT REALIZE
FULLEST EXTENT OF THIS COLD AIR AT THE SURFACE SINCE WILL WILL
MAINTAIN SOME MIXING/NORTHWEST WINDS WITH LINGERING PRESSURE
GRADIENT.
RIDGE OF HIGH PRESSURE BUILDS INTO/OVER THE AREA ON THURSDAY FOR
MOSTLY SUNNY SKIES. LOOKS LIKE HIGHS WILL REMAIN SOME 5 DEGREES OR
SO BELOW NORMAL THOUGH...TOPPING OFF IN THE LOWER 30S ACROSS THE
NORTH...TO THE LOWER 40S ACROSS THE SOUTH.
SOUTHERLY FLOW WILL INCREASE ACROSS THE AREA ON FRIDAY AHEAD OF A
LOW PRESSURE SYSTEM TRACKING ACROSS SOUTHERN CANADA AND A COLD FRONT
DROPPING SOUTH THROUGH MN. 925MB TEMPERATURES CLIMB INTO THE 6-8C
RANGE WITH AMPLE SUNSHINE. THIS SHOULD PRODUCE HIGHS IN THE MIDDLE
40 ACROSS THE NORTH...TO THE LOWER 50S ACROSS THE FAR SOUTH.
MODELS HAVE BEEN PRETTY CONSISTENT IN BRINGING A FAIRLY STRONG WAVE
OF LOW PRESSURE OUT INTO THE CENTRAL PLAINS FRIDAY NIGHT WITH
MODERATE AMOUNT OF 925-850MB MOISTURE TRANSPORT AND ISENTROPIC
LIFT...NOTED BY THE GFS ON THE 285-290K SURFACE. CARRIED SMALL RAIN
CHANCES MAINLY FOR AREAS ALONG AND SOUTH OF I-94. SOME OF THE RAIN
COULD BE MIXED WITH SNOW ALONG I-94 IN THE COLDER AIR.
.LONG TERM...SATURDAY THROUGH TUESDAY
309 PM CST TUE NOV 15 2011
15.12Z GFS/ECMWF SHOWING VERY GOOD AGREEMENT WITH REGARD TO THE
TRACK OF THE STORM SYSTEM AFFECTING THE UPPER MISSISSIPPI RIVER
VALLEY SATURDAY/SATURDAY NIGHT TIME FRAME. LOOKS LIKE THE AREA WILL
REMAIN ON THE WARM SIDE OF THE SYSTEM FOR LIKELY/HIGHER CHANCES OF
ALL RAIN THROUGH THE DAY SATURDAY. AS THE LOW PULLS UP INTO UPPER
MI/SOUTHERN ONTARIO SATURDAY NIGHT...COLDER AIR WILL FILTER INTO THE
AREA AS THE SOUTHERN EDGE OF THE DEFORMATION BAND PRECIPITATION
DRIFTS ACROSS THE AREA. SO...THERE WILL BE A CHANCE OF PERHAPS SOME
MINOR SNOW ACCUMULATION ACROSS THE NORTH/NORTH OF I-94 SATURDAY
NIGHT IF THE SNOW RATES ARE HIGH ENOUGH. WILL HAVE TO KEEP AN EYE ON
THIS OVER THE NEXT COUPLE OF MODEL RUNS. WEATHER THEN DRIES OUT BUT
REMAINS ON THE COOL SIDE SUNDAY/SUNDAY NIGHT AS HIGH PRESSURE BUILDS
IN FROM CANADA. LOOK FOR HIGHS ON SUNDAY ONLY IN THE 30S. MODELS
BRING A WEAK MID-LEVEL TROUGH ACROSS THE AREA ON MONDAY FOR A SMALL
CHANCE OF RAIN OR SNOW. SLIGHTLY MILDER AIR EXPECTED TO WORK BACK
INTO THE AREA ON TUESDAY AS HIGH PRESSURE MOVES INTO THE GREAT LAKES
REGION AND SOUTHWEST WINDS INCREASE.
&&
.AVIATION...THROUGH 18Z WEDNESDAY
1150 AM CST TUE NOV 15 2011
THE COLD FRONT AND WIND SHIFT FROM 210 TO 270 DEGREES WAS LOCATED
RIGHT ON KRST AT 1730Z AND WILL CONTINUE TO MOVE EAST TOWARD
KLSE. THE FRONT REPRESENTS THE LEADING EDGE OF WIND GUST POTENTIAL
IN WESTERLY WINDS. THIS FRONT WILL ARRIVE AT KLSE AROUND 20Z.
CONFIDENCE IS HIGH IN THIS TIMING.
REVIEWING OBSERVATIONAL DATA AT MID-DAY AND RECENT SHORT TERM
MODEL GUIDANCE FROM RUC AND NAM...IT APPEARS THE WINDS WILL NOT BE
QUITE AS HIGH AS ORIGINALLY FORECAST. LOW-LEVEL PROFILER DATA
SUGGESTS WINDS IN THE 30-35 KT RANGE AT 5KFT MOVING IN FROM THE
WEST OVER KRST THIS AFTERNOON WITH LITTLE INCREASE ABOVE. THIS
WOULD SUGGEST AN UPWARD BOUND TO THE WIND GUST SHOULD BE IN THAT
RANGE ROUGHLY. THUS...HAVE TAKEN A STEP DOWN IN THE WIND FORECASTS
FOR THIS AFTERNOON. CONFIDENCE IS MODERATE TO HIGH IN THIS LOWER
SPEED. THE HARDER PART OF THE FORECAST IS TRYING TO DETERMINE IF
ENOUGH INSTABILITY WILL BUILD IN THIS EVENING...WHEN WIND FIELD
LOOKS TO HAVE MOST POTENTIAL FOR HIGHER GUSTS. WE HAVE CONTINUED
THE THEME OF LOWER GUSTING THIS EVENING IN THE 00-03Z WINDOW...BUT
THE GUSTS COULD BE HIGHER BY 10 KTS SHOULD STABILITY NEAR THE
SURFACE NOT BUILD IN.
AN STRONG WEATHER IMPULSE TO THE NORTH WILL PROVIDE A SMALL WINDOW
OF SHOWER POTENTIAL OVER THE TAF SITES CENTERED ON 22Z FOR KRST AND
00Z FOR KLSE. HAVE INCLUDED VCSH AS MOST OF THE ACTIVITY WILL BE
ELEVATED WITH BASES NEAR 8-10KFT AND MORE ISO-SCT IN
COVERAGE...SHOULD IT DEVELOP. CONFIDENCE IS LOW-MODERATE IN THIS
OCCURRENCE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
309 PM CST TUE NOV 15 2011
WI...NONE.
MN...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR
MNZ086-087-094-095.
IA...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR
IAZ008>010-018-019-029.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1150 AM CST TUE NOV 15 2011
.SHORT TERM...
1150 AM CST TUE NOV 15 2011
HAVE BEEN REVIEWING LATEST WIND INFORMATION AND THE SIGNALS ARE
STEPPING BACK OFF THE ADVISORY CRITERIA WIND SPEEDS. EARLY MORNING
RUC GUIDANCE HAS INDICATED ONLY LATEST RUC MODEL GUIDANCE HAS BEEN
HINTING AT ABOUT A 5KT DECREASE IN THE MIXED LAYER WIND FIELD
LATER THIS AFTERNOON. THE 15.12Z NAM HAS COME IN WITH THAT SAME
SUGGESTION...AND THE STRONGER LOW-LEVEL WIND FIELD COMING IN
DURING THE EVENING POST POTENTIAL VORTICITY VERTICAL MOTION AXIS
MOVES THROUGH /SEE BELOW/. THE NAM AND GFS MOS BOTH DROPPED INTO
NON-ADVISORY VALUES AND JUST A BREEZY DAY. WOOD LAKE MN PROFILER
AND KABR 88D ARE SHOWING 30 KTS AT 17Z 850MB SO THIS IS NOT
ENCOURAGING AND STRONGEST RUC 850 MB HEIGHT GRADIENT REMAINS TO
THE NORTH CLOSER TO THE SW SIDE OF THE LOW TRACK. SO...THE
SIGNALS OF DEEP SUBSIDENCE...STRONGEST COLD ADVECTION...AND
STRONGEST WIND FIELD ALL TARGET THE EVENING WHEN THE BOUNDARY
LAYER WILL BE TRYING TO STABILIZE. THIS EQUATION A TOUGH ONE TO
WRESTLE WITH AS SOME POTENTIAL GUST MAGNITUDE IS TYPICALLY LOST
WITH NOCTURNAL STABILIZATION. HOWEVER...THE WIND FIELD BEING UP
DOES LEND ITSELF TO REMAINING MORE MIXED AND KEEPING LAPSE RATES
STEEP TO TAP WINDS ALOFT IN THE EVENING. BOTTOM LINE IS WINDS THIS
AFTERNOON WILL LIKELY BE SUB-ADVISORY BUT GUSTY...WITH POSSIBLY
MORE ADVISORY WIND GUSTS IN THE EARLY EVENING SHOULD STABILIZING
BOUNDARY LAYER NOT WIN OUT. WILL TRY TO TARGET PRODUCTS FOR THAT
SCENARIO AND HOLD ONTO ADVISORY FOR NOW...BUT CONFIDENCE IS
DIMINISHING FOR ADVISORY CRITERIA TO BE REACHED.
FOR LATER TODAY TOO...THE TIGHT CURL OF A DEEPER TROPOPAUSE FOLD
AND POTENTIAL VORTICITY AREA NOW EAST OF KBIS WILL SHIFT EAST BUT
WILL PROVIDE SOME FORCING OVER THE NORTHERN WI AREA AND INTO THE
FORECAST AREA. THIS WILL LIKELY MANIFEST ITSELF IN A THIN BAND OF
SHOWERS ALONG THE SOUTHERN TAIL OF THE POTENTIAL VORTICITY /
TROPOPAUSE FOLD AS IT MOVES EAST. THERMODYNAMICALLY...THE AIR MASS
THAT HAS BEEN IN PLACE FROM ABOUT 800 MB UP HAS HAD SOME
INSTABILITY CONDITIONAL ON SATURATION. WITH A HUNDRED CAPE OR SO
ALOFT WITH SATURATION...SOME SHOWERS HAVE BEEN FORMING. WE HAVE
HAD A DRY BIAS AND SO AM CONSIDERING SOME RAIN AND RAIN/SNOW
CHANCES AROUND THE 00Z TIME FRAME FOR THAT N-S ORIENTED LINE. IT
WOULD BE A BRIEF TIME OF SHOWERS AT ANY ONE POINT - ABOUT AN HOUR.
THE ECHO LINE WOULD ROUGHLY BE ON THE MISS RIVER AROUND 6 PM.
.LONG TERM...FRIDAY THROUGH MONDAY
328 AM CST TUE NOV 15 2011
15.00 MEDIUM RANGE MODELS IN GOOD AGREEMENT ON FRIDAY...SHOWING THE
UPPER LEVEL TROUGH MOVING FROM THE PACIFIC NORTHWEST INTO THE
CENTRAL ROCKIES. A STATIONARY FRONT WILL BE SITUATED FROM CENTRAL
WISCONSIN....SOUTHWEST INTO CENTRAL NEBRASKA. SURFACE LOW PRESSURE
WILL DEVELOP ALONG THE BAROCLINIC ZONE/FRONT ACROSS NEBRASKA. AS
THE TROUGH EJECTS EAST OUT OF THE ROCKIES...THE SURFACE LOW WILL
CONTINUE TO DEEPEN. THE FRONT WILL START TO LIFT NORTHWARD AS WARM
FRONT FRIDAY NIGHT. MOISTURE TRANSPORT IS EXPECTED TO INCREASE
ACROSS THE FORECAST AREA AS THE LOW PUSHES INTO EASTERN NEBRASKA.
LOOK FOR RAIN TO SPREAD ACROSS THE AREA FROM SOUTH TO NORTH
FRIDAY NIGHT AS THE LOW LIFTS INTO WESTERN IOWA. THE WARM FRONT
LOOKS TO BISECT THE FORECAST AREA SATURDAY INTO SATURDAY NIGHT
WITH THE SURFACE LOW TRACKING ACROSS NORTHEAST IOWA THROUGH WEST
CENTRAL WISCONSIN. DEPENDING ON THE POSITION OF THE FRONT...RAIN
MAY MIX WITH OR CHANGE OVER TO SNOW AT TIMES...WITH ACCUMULATIONS
POSSIBLE NORTH OF INTERSTATE 90. AT THIS TIME NORTHWEST
WISCONSIN/WESTERN UPPER MICHIGAN LOOKS TO HAVE THE BEST CHANCE OF
SEEING ACCUMULATING SNOW...POSSIBLY HEAVY AT TIMES SATURDAY INTO
SATURDAY NIGHT. WILL HAVE TO MONITOR THE LOW TRACK/FRONTAL
POSITION VERY CLOSELY THE NEXT FEW MODEL RUNS. THE LOW IS EXPECTED
TO LIFT INTO NORTHEAST WISCONSIN/EASTERN UPPER MICHIGAN SATURDAY
NIGHT INTO SUNDAY AS HIGH PRESSURE BUILDS INTO THE FORECAST AREA.
DEPENDING ON THE POSITION OF THE FRONT...HIGH TEMPERATURES ON
SATURDAY ARE EXPECTED TO RANGE FROM THE LOWER 40S ACROSS NORTH
CENTRAL WISCONSIN TO THE LOWER 50S ACROSS NORTHEAST IOWA INTO FAR
SOUTHWEST WISCONSIN. COOLER AIR WILL RETURN ON SUNDAY AS WITH COLD
HIGH PRESSURE MOVING IN. LOOK FOR HIGHS TO FALL INTO THE LOWER 30S
TO LOWER 40S. THE HIGH WILL BRING DRY AND COOL CONDITIONS TO THE
REGION SUNDAY NIGHT THROUGH MONDAY.
&&
.AVIATION...THROUGH 18Z WEDNESDAY
1150 AM CST TUE NOV 15 2011
THE COLD FRONT AND WIND SHIFT FROM 210 TO 270 DEGREES WAS LOCATED
RIGHT ON KRST AT 1730Z AND WILL CONTINUE TO MOVE EAST TOWARD
KLSE. THE FRONT REPRESENTS THE LEADING EDGE OF WIND GUST POTENTIAL
IN WESTERLY WINDS. THIS FRONT WILL ARRIVE AT KLSE AROUND 20Z.
CONFIDENCE IS HIGH IN THIS TIMING.
REVIEWING OBSERVATIONAL DATA AT MID-DAY AND RECENT SHORT TERM
MODEL GUIDANCE FROM RUC AND NAM...IT APPEARS THE WINDS WILL NOT BE
QUITE AS HIGH AS ORIGINALLY FORECAST. LOW-LEVEL PROFILER DATA
SUGGESTS WINDS IN THE 30-35 KT RANGE AT 5KFT MOVING IN FROM THE
WEST OVER KRST THIS AFTERNOON WITH LITTLE INCREASE ABOVE. THIS
WOULD SUGGEST AN UPWARD BOUND TO THE WIND GUST SHOULD BE IN THAT
RANGE ROUGHLY. THUS...HAVE TAKEN A STEP DOWN IN THE WIND FORECASTS
FOR THIS AFTERNOON. CONFIDENCE IS MODERATE TO HIGH IN THIS LOWER
SPEED. THE HARDER PART OF THE FORECAST IS TRYING TO DETERMINE IF
ENOUGH INSTABILITY WILL BUILD IN THIS EVENING...WHEN WIND FIELD
LOOKS TO HAVE MOST POTENTIAL FOR HIGHER GUSTS. WE HAVE CONTINUED
THE THEME OF LOWER GUSTING THIS EVENING IN THE 00-03Z WINDOW...BUT
THE GUSTS COULD BE HIGHER BY 10 KTS SHOULD STABILITY NEAR THE
SURFACE NOT BUILD IN.
AN STRONG WEATHER IMPULSE TO THE NORTH WILL PROVIDE A SMALL WINDOW
OF SHOWER POTENTIAL OVER THE TAF SITES CENTERED ON 22Z FOR KRST AND
00Z FOR KLSE. HAVE INCLUDED VCSH AS MOST OF THE ACTIVITY WILL BE
ELEVATED WITH BASES NEAR 8-10KFT AND MORE ISO-SCT IN
COVERAGE...SHOULD IT DEVELOP. CONFIDENCE IS LOW-MODERATE IN THIS
OCCURRENCE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
328 AM CST TUE NOV 15 2011
WI...NONE.
MN...WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
MNZ086-087-094-095.
IA...WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
IAZ008>010-018-019-029.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....WETENKAMP
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1101 AM CST TUE NOV 15 2011
.UPDATE...
LIGHT RAIN ASSOCIATED WITH WARM AIR ADVECTION AHEAD OF SFC LOW
PRESSURE OVER WEST CENTRAL WISCONSIN FELL NORTH OF THE FORECAST AREA
THIS MORNING. THERE MAY HAVE BEEN A FEW SPRINKLES FALLING OUT OF THE
10000 FT CEILINGS IN THE NORTHERN FORECAST AREA...BUT THAT WAS IT.
THIS AREA OF LIGHT RAIN SHOWERS WILL CONTINUE TO SHIFT NORTHEAST
THIS AFTERNOON.
CLEARING SKIES MIDDAY...AS WELL AS MIXING UP TO 925MB MAY ALLOW
FOR MAX TEMPS TO REACH A DEGREE OR TWO HIGHER THAN PREVIOUSLY
FORECAST. EXPECTING SOME DECENT GUSTS TO 30 MPH OR SO LATE THIS
AFTERNOON AS WELL. AN AREA OF CIRRUS CLOUDS OVER IOWA IS EXPECTED
TO ADVECT INTO SOUTHERN WI THIS AFTERNOON...WHICH IS ASSOCIATED
WITH DIVERGENCE ALOFT.
MEANWHILE...A COLD FRONT WILL MARCH ACROSS THE UPPER MIDWEST TODAY.
THE SFC WIND SHIFT FROM WSW TO W WILL OCCUR FAIRLY EARLY THIS
EVENING...THEN VEER TO THE WSW AROUND MIDNIGHT. COLD AIR ADVECTION
MAY HELP SOME OF THE GUSTY WINDS MIX DOWN TO THE SFC...ESPECIALLY
AFTER MIDNIGHT TONIGHT AND WEDNESDAY MORNING...AFTER THE SFC TROUGH
PASSES EAST OF THE AREA. NAM SNDGS ARE SHOWING A MUCH STRONGER SFC
INVERSION THAN THE GFS AND RUC THIS EVENING...WHICH WOULD INHIBIT
THE GUSTIER WINDS FROM MIXING DOWN. THE NAM SEEMS TO MAKE SENSE
THIS EVENING BECAUSE THAT IS WHEN THE SFC TROUGH WILL BE COMING
ACROSS AND THUS THE WEAKER PRESSURE GRADIENT.
&&
.AVIATION/18Z TAFS/...
DELAYED THE ONSET OF THE GUSTIER WINDS UNTIL EARLY THIS AFTERNOON.
WHILE THE PRESSURE GRADIENT IS STRENGTHENING AND SFC WINDS ARE
GRADUALLY INCREASING...THE STRONG MORNING INVERSION STILL NEEDS
TIME TO WEAR AWAY IN ORDER TO TAP INTO THE STRONGER WINDS BETWEEN
1000 AND 2000 FEET AGL.
SURFACE LOW PRESSURE WILL TRACK FROM WEST CENTRAL WISCONSIN TO
LAKE SUPERIOR THIS AFTERNOON AND EVENING...AND DRAG A COLD FRONT
ACROSS SOUTHERN WI. VFR CONDITIONS THROUGH THE PERIOD. CLEAR SKIES
WILL GIVE WAY TO BROKEN/OVERCAST CIRRUS CLOUDS THIS AFTERNOON. SFC
WINDS WILL GRADUALLY VEER SOUTHWEST THIS AFTERNOON...THEN WEST
THIS EVENING...THEN WNW AND INCREASE AFTER MIDNIGHT WITH COLDER
AIR WORKING INTO THE REGION BEHIND THE FRONT.
LOW LEVEL WIND SHEAR PROBABLY TONIGHT AT ALL TAF SITES...
ESPECIALLY IN THE EVENING WITH A STRONG SURFACE INVERSION. WIND
GUSTS WILL INCREASE TOWARD WED MORNING AS THE INVERSION ERODES
AWAY WITH COLD AIR ADVECTION.
&&
.MARINE...
WINDS ARE SLOWER TO INCREASE TO SMALL CRAFT ADVISORY CONDITIONS
THIS MORNING...SINCE THE INVERSION WAS QUITE STRONG AND IS TAKING
TIME TO ERODE AWAY. HOWEVER...THE GUSTY SSW WINDS WILL HAPPEN
EARLY THIS AFTERNOON AND CONTINUE THROUGH WEDNESDAY AFTERNOON.
THERE WILL PROBABLY BE A LULL IN THE GUSTY WINDS THIS EVENING AS
THE SURFACE TROUGH/COLD FRONT MOVES ACROSS SOUTHERN LAKE
MICHIGAN...BUT WINDS WILL QUICKLY INCREASE EARLY WEDNESDAY MORNING
AS COLDER AIR WORKS INTO THE AREA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM CST WEDNESDAY FOR LMZ643>646.
&&
$$
UPDATE...MRC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1154 PM EST WED NOV 16 2011
.SHORT TERM /TONIGHT AND THURSDAY/...
POTENT SHORTWAVE THAT MOVED THROUGH THE CWA LAST NIGHT WILL CONTINUE
NE THROUGH QUEBEC TONIGHT...LEAVING THE AREA UNDER AN UPPER TROUGH
FOR MUCH OF THE SHORT TERM PERIOD. LOW/MID LVL MOISTURE BEHIND THE
WAVE HAS SETTLED OVER THE NE HALF OF THE CWA TODAY AND IS EXPECTED
TO REMAIN THROUGH THE FIRST HALF OF THURS. THIS HAS AIDED SOME
SHOWER DEVELOPMENT OVER THE ERN LK THROUGH THE DAY. THESE BANDS HAVE
A NW TO SE APPEARANCE DUE TO THE NW WINDS ALOFT...BUT THE LLVL WINDS
W TO WNW WINDS HAVE BEEN GRADUALLY PUSHING THEM E. DRIER LLVL AIR
OVER WRN LK SUPERIOR HAS TRIED TO LIMIT LES EXTENT OVER THE WRN
U.P...BUT AN ADDITIONAL AREA OF LOW/MID LVL MOISTURE OVER NRN MN
/PRODUCING SCATTERED SHSN/ SHOULD BEGIN TO MOVE INTO THE AREA THIS
EVENING.
WITH THE AREA BETWEEN THE HIGH TO THE SW AND THE EXITING LOW IN
QUEBEC...EXPECT WNW FLOW TO CONTINUE THROUGH THURS. A LINGERING
TROUGH FROM THE EXITING LOW OVER ERN LK SUPERIOR FOR TONIGHT INTO
THURSDAY WILL HELP TO FOCUS WINDS A LITTLE MORE OUT OF THE NW OVER
NRN LUCE AND FAR ERN ALGER COUNTY AND INCREASE THE LLVL CONVERGENCE
IN THAT AREA. RUC ANALYSIS OF H850 TEMPS SHOWS VALUES RANGING FROM
-11C OVER WRN LK SUPERIOR TO -8C OVER ERN LK SUPERIOR. THESE TEMPS
SHOULD FALL A COUPLE DEGREES BY 12Z THURS WITH THE SECONDARY SURGE
OF COLD AIR BEHIND A WEAK H850 TROUGH AND REMAIN THROUGH THE DAY
THURS. THIS CREATES DELTA-T VALUES IN THE UPPER TEENS ACROSS THE LK
THROUGH THE PERIOD.
OVER THE W...PARAMETERS HAVE REALLY COME TOGETHER FOR MODERATE TO
POTENTIALLY HEAVY LES TONIGHT INTO TOMORROW MORNING. WITH THE
SLIGHTLY COLDER H850 TEMPS THERE...EXPECT MUCH OF THE LK INDUCED
FORCING TO BE RIGHT IN THE DGZ. MODELS STILL HINTING AT LLVL DRY AIR
OVER THE WRN CWA KEEPING CLOUD BASES NEAR 3KFT THROUGH THIS
EVENING...WHICH WILL LIMIT THE DEPTH OF THE CLOUD WITH EQL VALUES
FROM 7-10KFT. BUT H925-850 MOISTURE CURRENTLY LOCATED OVER NRN MN
SHOULD PUSH OVER WRN LK SUPERIOR AND THE WRN CWA OVERNIGHT TONIGHT
AND INTO TOMORROW MORNING. THIS SHOULD PROVIDED ADDITIONAL LLVL
MOISTURE TO REALLY ENHANCE THE LES IN THE WNW FAVORED LOCATIONS. LES
PARAMETER IS SHOWING THIS WELL...WITH A DIMINISHING TREND LATE THIS
AFTN AND INTO THE EVENING...BEFORE GREATLY INCREASING OVERNIGHT AND
INTO THURS MORNING. BIGGEST CONCERN IS THE WHAT THE EQL WILL BE.
BUFKIT SOUNDINGS DO HAVE SOME VARIABILITY ON IF THE EQL/S WILL RISE
TOWARDS 12-15KFT OVERNIGHT INTO THURS MORNING...WHICH DEPENDS ON A
DEGREE F OR TWO DIFFERENCE IN THE LK TEMPS. IF THAT OCCURS...COULD
SEE SNOW AMOUNTS BEING HIGHER THAN EXPECTED. FELT THE CURRENT
FORECAST WAS ON TRACK WITH HIGH END ADVISORY AMOUNTS WHERE THERE
WILL LIKELY BE ENHANCED CONVERGENCE OVER NRN ONTONAGON AND CENTRAL
HOUGHTON COUNTIES. THE EVENING SHIFT WILL NEED TO MONITOR TRENDS AND
IF THE SNOW BECOMES HEAVY EARLIER THAN EXPECTED...MAY NEED TO BUMP
UP THE ADVY TO A WARNING.
OVER THE E...WITH THE DEEPER MOISTURE AND EQL NEAR 15KFT FROM THE
EXITING WAVE...LES PARAMETERS ARE MUCH BETTER IN THIS AREA AND
SHOWING POTENTIAL FOR MODERATE TO HEAVY SNOW. THERE POTENTIALLY TWO
LIMITING FACTORS ON SNOW AMOUNTS REACHING WARNING CRITERIA.
FIRST...PREVIOUS SHIFT MENTIONED THE POTENTIAL FOR SNOW PELLETS OR
GRAUPEL AT TIMES TONIGHT...WHICH SEEMS REASONABLE THIS EVENING WITH
THE SLIGHTLY WARMER H850 TEMPS KEEPING THE BEST OMEGA BELOW THE DGZ.
BUT...AS TEMPS COOL OVERNIGHT BEHIND THE H850 TROUGH...EXPECT A
TRANSITION TO MAINLY SNOW. SECOND...THE WIND DIRECTION REMAINS A
CONCERN FOR TONIGHT. WITH NW WINDS SHIFTING MORE WRLY THROUGH THE
DAY TODAY...THE MAIN PCPN HAS BEEN RUNNING NEARLY PARALLEL TO SHORE
THIS AFTN. MODELS SHOW A SLIGHT WNW SHIFT TO THE H925 WINDS THIS
EVENING...BUT NOT SURE IF THIS WILL BE ENOUGH TO SLIDE THE DOMINATE
BAND ONSHORE FROM GRAND MARAIS EAST ALONG THE LUCE COUNTY SHORELINE.
WITH THE GEM/ECMWF/GFS AND LOCAL WRF SHOWING THE LINGERING SFC
TROUGH TIGHTENING UP OVER THE FAR ERN LK OVERNIGHT TONIGHT AND
DROPPING SE THURS MORNING...EXPECT THIS TO SHIFT THE WINDS NW ENOUGH
TO PUSH THE DOMINATE BAND INTO LUCE COUNTY. THUS...WITH
MODERATE/HEAVY SNOW...ALONG WITH GUSTY WINDS UP TO 30MPH...HAVE
SWITCHED THE LES WATCH OVER TO A WARNING FOR LUCE. WITH THE
UNCERTAINTY ON THE EXACT LOCATION OF THE BAND FOR THE GRAND MARAIS
AREA OF ALGER...HAVE SWITCHED THAT WATCH OVER TO AN LES ADVY...BUT
THERE REMAINS SOME BUST POTENTIAL BOTH WAYS. EXPECT THIS PERIOD OF
HEAVY SNOW TO CONTINUE THROUGH THURS MORNING UNDER THE NW WINDS.
CURRENT FORECAST HAS SNOWFALL AMOUNTS EXCEEDING A FOOT FOR PORTIONS
OF NRN LUCE COUNTY BY 00Z FRI.
DRIER MID LVL AIR BEGINS TO MOVE OVER THE SW HALF OF THE CWA THURS
AFTN...LOWERING THE EQL/S TOWARDS 5-6KFT BY 00Z FRI. THIS WILL
DIMINISH THE INTENSITY OF THE SHOWERS OVER THE W. OVER THE E...THESE
LESS FAVORABLE LES CONDITIONS DON/T ARRIVE UNTIL LATE THURS AFTN AND
INTO THURS EVENING AND HAVE ENDED THE WARNING AT 00Z.
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE SFC MAP AT 00Z STRONG HIGH PRESSURE ACROSS THE TN VALLEY WILL
EXTEND A RIDGE ACROSS WI AND WESTERN LAKE SUPERIOR...WITH A WEAK SFC
TROUGH EXTENDING FROM THE MAIN LOW OVER FAR EASTERN CANADA TO JUST
EAST OF LAKE SUPERIOR. THIS WILL ALLOW THE FOCUS FOR HEAVIER SNOW TO
DIMINISH ACROSS LAKE SUPERIOR...WITH NW WINDS BECOMING MORE AND MORE
WESTERLY AS THE EVENING PROGRESSES.
THE HIGH AMPLITUDE 500MB RIDGE OVER THE PACIFIC NORTHWEST AND
WESTERN CANADA WILL FLATTEN AS IT SLIDES ACROSS THE NORTHERN PLAINS
AND SOUTHERN MANITOBA BY 00Z FRIDAY. IT WILL STILL BE ENOUGH TO AT
LEAST TEMPORARILY SWEEP THE TROUGHS EAST OF THE AREA THURSDAY NIGHT
THROUGH THE START OF THE WEEKEND. HOWEVER...THE MAIN CULPRIT WILL
BUDGE LITTLE OVER THE SECOND HALF OF THE WORK WEEK...THAT BEING THE
500MB LOW SPINNING NEAR HUDSON BAY.
THE FAST SOUTHWESTERLY FLOW WILL RETURN...WITH THE APEX OF THE RIDGE
EXITING THE UPPER GREAT LAKES FRIDAY AFTERNOON/EVENING. ONE TROUGH
OVER NORTHERN MANITOBA AT 00Z SATURDAY SHOULD CROSS ONTARIO SATURDAY
AFTERNOON/EVENING. BEHIND THIS FEATURE A MORE DISTINCT TROUGH WILL
WASH OUT ALONG THE CANADIAN/U.S. BORDER...WITH A BROAD TROUGH
EXPECTED ACROSS LAKE SUPERIOR AND UPPER MI SATURDAY EVENING THROUGH
NEXT TUESDAY NIGHT. THE RESULT AT THE SFC WILL BE THE WEAKENING OF
THE 995MB SFC LOW CENTERED ACROSS SOUTHERN SASKATCHEWAN AT 00Z
FRIDAY...TO 1003MB BY 00Z SATURDAY JUST NW OF LAKE SUPERIOR. EVEN
WITH THE WEAKENING OF THIS SYSTEM THE TIGHTENING PRESSURE GRADIENT
WILL RESULT IN STRONGER SW WINDS AT THE SFC FRIDAY INTO EARLY FRIDAY
EVENING...MAINLY ACROSS THE EASTERN HALF OF THE CWA. THE RESULT WILL
BE A TROUGH OF LOW PRESSURE AT THE SFC EXTENDING BETWEEN 2 STRONGER
LOW OVER HUDSON BAY AND KANSAS AT 12Z SATURDAY OVER THE EAST HALF.
LOOK FOR A LOW TO PUSH NORTHEASTWARD ALONG THIS TROUGH FROM THE
CENTRAL TO SOUTHERN PLAINS. MODELS CONTINUE TO PLAY THE LOW TRACKING
NEAR THE STRAITS AROUND 06Z SUNDAY...WITH THE NAM FARTHEST
NORTH...AND THE ECMWF ON THE SOUTHERN END OF THE FORECAST ENVELOP.
THE CANADIAN LOOKS TO BE ABOUT 6 HOURS SLOW. MODERATE TO HEAVY SNOW
ACCUMULATIONS REMAIN POSSIBLE OVER THE WESTERN HALF OF UPPER MI
UNTIL HIGH PRESSURE BUILDS IN FROM THE WEST SUNDAY AFTERNOON.
LOOKING A BIT FARTHER OUT...THERE ARE A COUPLE OF 500MB WAVES WITHIN
THE BROAD TROUGH /WESTERLY FLOW/ THAT ARE DIFFICULT TO FORECAST. THE
FIRST WAVE FOR MONDAY IS MORE DISTINCT OFF THE 16/12Z RUN OF THE
GFS...BUT IS SIMILAR TIMING WISE...BUT IS MUCH WEAKER THAN WHAT IS
SHOWN OFF THE 16/00Z ECMWF. THE CANADIAN IS OUT OF PHASE WITH THE
GFS AND ECMWF STARTING AROUND 12Z MONDAY...OR ABOUT 6 HOURS SLOWER.
A SIMILAR TREND WAS NOTED WITH THE TUESDAY AFTERNOON/EVENING WEAK
TROUGH...WHERE THE GFS TIGHTENED UP THE TROUGH A BIT MORE THAN THE
ECMWF. FORECAST MODELS ARE ABOVE NORMAL CONSISTENCY WISE FOR NEXT
WEDNESDAY...WITH A LARGE 500MB RIDGE BUILDING IN FROM THE PLAINS
STATES.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
COLD AIR MOVING ACROSS LAKE SUPERIOR WILL PRODUCE CLOUDS AND LAKE
EFFECT SNOW FOR THE WEST TO NORTHWEST WIND SNOW BELTS FOR THE TAF
PERIOD. THIS WILL LARGELY AFFECT KCMX WITH PERIODS OF MVFR CIGS
AND IFR VSBYS. WITH KIWD NOT BEING UNDER FAVORABLE FLOW FOR
SNOW...HAVE LEFT OUT MENTION...BUT DID KEEP MVFR CIGS FOR THE
OVERNIGHT PERIOD FROM MOISTURE CURRENTLY IN NRN MN. KSAW WILL SEE
VFR CONDITIONS THROUGH THE PERIOD. KIWD AND KCMX WILL BECOME VFR AS
SW WINDS WILL PUSH THE LAKE EFFECT CLOUDS OFFSHORE LATE THU
AFTERNOON INTO THU EVENING.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
LOW PRESSURE ACROSS CENTRAL ONTARIO WILL KEEP A WEAK TROUGH ACROSS
EASTERN LS OVERNIGHT...WHICH WILL ASSIST IN FOCUSING THE STRONGER
GALE FORCE WINDS OF 35KTS OVER THE EASTERN HALF OF LS THROUGH THIS
EVENING. LOOK FOR A RIDGE OF HIGH PRESSURE TO BUILD IN THURSDAY INTO
THURSDAY NIGHT...WITH GUSTS CONTINUING 20 TO 30KTS. LOW PRESSURE
ACROSS SOUTHERN SASKATCHEWAN THURSDAY NIGHT WILL FILL SLIGHTLY JUST
NORTH OF LS FRIDAY NIGHT. AHEAD OF THIS FEATURE...STRONG SW WINDS
FRIDAY INTO FRIDAY NIGHT MAY RESULT IN A FEW GALE FORCE GUSTS ACROSS
EASTERN LS. EXPECT A NEARLY STATIONARY TROUGH OVER EASTERN LS ON
SATURDAY. LOW PRESSURE OVER THE CENTRAL PLAINS SATURDAY WILL MOVE
ALONG THE TROUGH...FILLING SLIGHTLY ACROSS NORTHERN LOWER MICHIGAN
BY SATURDAY NIGHT...WITH A BRIEF PERIOD OF NE GALES TO 35KT SATURDAY
AFTERNOON THAT MAY TRANSITION ACROSS THE ENTIRE LAKE AS WINDS TURN
MORE NORTHWESTERLY AS THE LOW EXITS NE. HIGH PRESSURE SHOULD SLIDE
IN FROM THE WEST SUNDAY...BEFORE SLOWLY DIPPING TO THE LOWER GREAT
LAKES ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THURSDAY FOR MIZ001>003-
084.
LAKE EFFECT SNOW WARNING FROM 10 PM THIS EVENING TO 7 PM EST
THURSDAY FOR MIZ007.
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 5 PM EST
THURSDAY FOR MIZ006.
LAKE SUPERIOR...NONE.
LAKE MICHIGAN...NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...07
MARINE...SRF/SF
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
920 AM EST THU NOV 17 2011
.SYNOPSIS...
COLD HIGH PRESSURE WILL MOVE ACROSS THE OHIO VALLEY TODAY AND
FRIDAY. REMAINING LIGHT SNOW SHOWERS WILL END ACROSS THE MOUNTAINS
BY TONIGHT. EXPECT SUNSHINE FRIDAY AND SATURDAY. A MIDWEST COLD
FRONT WILL PASS THROUGH SUNDAY WITH SCATTERED RAIN SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
PER RECENT RADAR, SATELLITE, AND SURFACE DATA AND HRRR MODEL
OUTPUT, EXPECT MAINLY JUST ISOLATED LIGHT SNOW SHOWERS ACROSS THE
I-80 CORRIDOR AND MOUNTAINS THIS MORNING. WITH PASSAGE OF COLD
UPPER TROUGH THIS AFTERNOON, EXPECT AN INCREASE IN INSTABILITY AND
HENCE COVERAGE OF SHOWERS INTO EARLY EVENING. NAM MODEL PROFILES
SUGGEST SURFACE WINDS CAN GUST TO 30 MPH.
AS DRY AND COLD SURFACE HIGH BUILDS IN TOWARDS THE REGION
TONIGHT, SKIES WILL CLEAR.
NOT MUCH TEMPERATURE RECOVERY EXPECTED TODAY DUE TO THE COLD
ADVECTION. SPECIFIC VALUES FORECASTED USING CONSENSUS OF RECENT
GFS AND NAM MOS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL DOMINATE FRIDAY INTO SATURDAY WITH A DRY
CONDITIONS AND A GRADUAL MODERATING OF TEMPERATURES ESPECIALLY
SATURDAY WHEN HIGHS WILL REACH ABOVE NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
PROGRESSIVE PATTERN IS FORECAST OVER THE GREAT LAKES AND UPPER
OHIO REGIONS FOR THE LONG TERM PERIOD WITH RIDGING OVER THE GULF
AND TROUGHING OVER THE PAC NW/WEST COAST. SHORTWAVES WITHIN THE
FAST FLOW WILL DEFINE THE SENSIBLE WEATHER FOR THE REGION...HENCE
WILL BE DIFFICULT TO TIME.
HAVE RAISED POPS TO LIKELY FOR SUNDAY FOR THE APPROACH AND
PASSAGE OF A COLD FRONT ASSOCIATED WITH LOW PRESSURE PROGGED TO
RACE ACROSS THE GREAT LAKES. THEREAFTER...FORECAST WAS BASED
GFS/ECMWF BLENDED-TIMING OF DISTURBANCES AND HPC TEMPERATURE
GUIDANCE WHICH IS REASONABLY AT...OR SLIGHTLY ABOVE THE SEASONAL
NORMALS.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
PER RECENT SURFACE AND SATELLITE DATA, EXPECT VFR COLD-POOL STRATOCUMULUS
TO REMAIN ACROSS THE UPPER OHIO VALLEY INTO EARLY EVENING. BRIEF
MVFR RESTRICTIONS ARE POSSIBLE MAINLY AT KFKL AND KDUJ DURING
THIS AFTERNOON DUE TO SCATTERED LAKE EFFECT SNOW SHOWERS. SURFACE
WINDS CAN GUST TO 25 KTS.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
HIGH PRESSURE WILL BUILD AND PROVIDE VFR TO THE UPPER OHIO REGION
THROUGH SATURDAY. THEREAFTER...THE CHANCE FOR RAIN AND RESTRICTIONS
WILL INCREASE WITH THE APPROACH AND PASSAGE OF ANOTHER COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
654 AM EST THU NOV 17 2011
UPDATED AVIATION DISCUSSION FOR 12Z TAFS
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM
HUDSON BAY S THRU THE MISSISSIPPI VALLEY. WELL UPSTREAM...A DEEP
MIDLEVEL LOW IS DROPPING DOWN THE BRITISH COLUMBIA COAST. OVER THE
NEXT COUPLE OF DAYS...THIS SYSTEM WILL AID TROF DEVELOPMENT OVER THE
WRN CONUS...RESULTING IN DOWNSTREAM FLOW BECOMING SW INTO THE GREAT
LAKES. CLOSER TO HOME...A SHORTWAVE IS SLOWLY MOVING ACROSS UPPER MI
ATTM...SUPPORTING INCREASING LES INTENSITY. JUST UPSTREAM...00Z KINL
SOUNDING SHOWED A FAVORABLE PROFILE FOR LES WITH DEEP MOISTURE UP TO
700MB AND 850MB TEMP OF -15C...RIGHT IN THE MIDDLE OF THE FAVORABLE
TEMP ZONE FOR DENDRITES. CANADIAN RADAR IMAGERY EARLIER IN THE NIGHT
SHOWED A VERY IMPRESSIVE DOMINANT BAND EXTENDING FROM LAKE NIPIGON
DOWN THE ERN SHORE OF LAKE SUPERIOR WHERE N/NE LAND BREEZE OFF
ONTARIO CONVERGED WITH STRONG W FLOW OVER THE LAKE. THAT BAND HAS
GIVEN WAY TO SEVERAL INTENSE SNOW BANDS OVER THE LAKE...AND RADAR
IMAGERY ALMOST SUGGESTS A MESO LOW DEVELOPING NE OF CARIBOU ISLAND.
CONVECTION IS DEEP AS KMQT RADAR CONTINUES TO INDICATE CLOUD TOPS
AROUND 20K FT. OVER THE W...AT LEAST A COUPLE OF DOMINANT BANDS HAVE
BEEN AFFECTING WRN UPPER MI. LAND BREEZE OFF NW WI HAS BEEN
SUPPORTING ONE BAND INTO THE AREA AROUND THE PORCUPINE MOUNTAINS E
TO BERGLAND PER KDLH RADAR. PUBLIC REPORT EARLIER IN THE NIGHT
INDICATED 3 INCHES OF SNOW...AND WEBCAM SUGGESTS POSSIBLY A FEW MORE
INCHES SINCE THEN. ANOTHER DOMINANT BAND HAD BEEN AFFECTING THE AREA
AROUND THE HOUGHTON COUNTY AIRPORT. AWAY FROM W WIND LES...
CLEAR/PARTLY CLOUDY SKIES HAVE BEEN THE RULE ACROSS MUCH OF THE
DOWNSLOPE AREAS OF THE CNTRL INTO ERN FCST AREA DURING THE NIGHT.
&&
.DISCUSSION...
LES SHOULD CONTINUE TO INCREASE OVER THE NEXT SEVERAL HRS GIVEN THE
FAVORABLE AIR MASS PROPERTIES AS INDICATED BY THE 00Z KINL SOUNDING.
SNOW RATES MAY BECOME FAIRLY IMPRESSIVE FOR A WHILE DURING THE
MORNING HRS...AND WILL NEED TO MONITOR FOR POSSIBLE SHORT TERM
UPGRADE OF ADVY TO WARNING OVER SOME PORTION OF THE W IF LOW-LEVEL
CONVERGENCE REMAINS FOCUSED AT ANY ONE LOCATION. TYPICALLY IN W WIND
REGIMES...LAND BREEZE OFF NW WI FORCES CONVERGENCE INTO AN AREA OF
FAR NRN ONTONAGON INTO ADJACENT HOUGHTON COUNTY...OFTEN AROUND TWIN
LAKES. HIGHER RES GUIDANCE SUGGESTS CONVERGENCE WILL REMAIN SET UP A
BIT FARTHER S AS HAS BEEN OCCURRING DURING THE NIGHT FROM THE
PORCUPINE MOUNTAINS TO BERGLAND. REGIONAL GEM AND ESPECIALLY THE
HIRES WRF-ARW HAVE DONE WELL DEPICTING SOME OF THE ACTIVITY OVER THE
WRN U.P. WILL THUS PAINT HIGHEST SNOW TOTALS IN ONTONAGON COUNTY AND
HOUGHTON COUNTY S OF TWIN LAKES. WILL PROBABLY FLIRT WITH 12HR-24HR
WARNING CRITERIA IN A FEW HIGHER TERRAIN LOCATIONS WHERE THE BEST
CONVERGENCE REMAINS NEARLY STATIONARY. TO THE E...W FLOW SO FAR
DURING THE NIGHT HAS KEPT MUCH OF THE LES OFFSHORE OF ERN ALGER/NRN
LUCE. LATEST RADAR TRENDS SHOW INCREASING LES INTENSITY/ORGANIZATION
OVER ERN LAKE SUPERIOR. AS WINDS VEER SLIGHTLY WITH PASSING
SHORTWAVE...ENHANCED CONVERGENCE ZONE SHOULD SHIFT S INTO NE
ALGER/NRN LUCE THIS MORNING. FAVORABLE INSTABILITY/MOISTURE AND
ONGOING HVY SNOW OVER NE/E LAKE SUPERIOR INDICATE POTENTIAL FOR
SIGNIFICANT LES OVER THE NEXT 12HRS. INTERESTING TO NOTE THAT THE
REGIONAL GEM REALLY ENHANCES THE N/NE LAND BREEZE OFF ONTARIO BEHIND
PASSING SHORTWAVE...ENOUGH SO THAT A LAKE NIPIGON ENHANCED HVY SNOW
BAND SHIFTS SW ALL THE WAY TO PICTURED ROCKS. HIGH RES WRF-ARW AND
LOCAL HIGH RES WRF HAVE A SIMILAR SCENARIO...BUT ONLY PUSH
CONVERGENCE ZONE AS FAR SW AS LUCE COUNTY TO POSSIBLY GRAND MARAIS.
STRONGLY FOCUSED CONVERGENCE/LAKE NIPIGON PRECONDITONING AND DEEP
CONVECTIVE/MOIST LAYER (KMQT RADAR INDICATES CLOUD TOPS TO 20K FT)
POINT TO INTENSE SNOWFALL RATES WHEN BANDS SHIFT SW INTO LUCE/NE
ALGER COUNTY. AT THIS POINT...LUCE COUNTY IS MOST LIKELY TO FALL
UNDER THE HEAVIER SNOW...SO WARNING LOOKS ON TRACK THERE. THERE IS
MORE UNCERTAINTY FOR ALGER SINCE BULK OF GUIDANCE DOES NOT SHIFT
CONVERGENCE ZONE AS FAR SW AS REGIONAL GEM/LOCAL HIGH RES WRF. FOR
NOW...WILL LEAVE ADVY FOR ALGER...BUT TRENDS WILL NEED TO MONITORED
CLOSELY THIS MORNING. AWAY FROM LES...EXPECT PARTLY TO MOSTLY CLOUDY
SKIES TODAY...THOUGH WHERE W WIND DOWNSLOPING IS MAXIMIZED IN CNTRL
UPPER MI...THERE MAY BE QUITE A BIT OF SUN THRU THE DAY.
LOW-LEVEL WINDS WILL BEGIN TO BACK LATE AFTN AND THRU TONIGHT...
SHIFTING LES N AND EVENTUALLY OUT OF UPPER MI. LAST OF THE LES
SHOULD PROBABLY EXIT UPPER MI AROUND 06Z TONIGHT. AHEAD OF THE
AMPLIFYING WRN CONUS TROF...A SHORTWAVE WILL STREAK E ALONG
U.S./CANADA BORDER TONIGHT/FRI. WAA REGIME AHEAD OF THE WAVE WILL
ALREADY BE SPREADING INTO THE UPPER GREAT LAKES OVERNIGHT. THERE
REMAINS UNCERTAINTY IN HOW FAR S SATURATION WILL OCCUR IN THE
WAA/STRONG ISENTROPIC REGIME. GIVEN THE STRENGTH OF ASCENT...AT
LEAST LOW POPS ACROSS THE N SEEM REASONABLE. AS WINDS BACK ACROSS
LAKE MICHIGAN...ADDITIONAL LOW-LEVEL MOISTENING SUPPORTS EXTENDING
POPS S ACROSS THE ERN FCST AREA AS WELL.
COLD FRONT ASSOCIATED WITH WAVE WILL DRIFT SE INTO UPPER MI FRI
NIGHT/EARLY SAT AND THEN BECOME STATIONARY AS SHORTWAVE EJECTS FROM
WRN TROF. MODELS CONTINUE TO SHOW GOOD CONTINUITY ON THIS SYSTEM. IF
ANYTHING...THERE APPEARS TO BE A SLIGHT OVERALL MODEL TREND TOWARD A
WEAKER/FLATTER WAVE OVER THE LAST SEVERAL MODEL RUNS. CLUSTERING OF
GUIDANCE IS GOOD WITH ALL INDICATING VERY SIMILAR TRACKS FROM KS
TO THE STRAITS AREA. SINCE SYSTEM WILL BE RELATIVELY FLAT/FAST
MOVING...THIS WILL MOST LIKELY BE AN ADVY TYPE SNOW EVENT SAT
AFTN/NIGHT OVER MUCH OF W AND CNTRL UPPER MI. RAIN/SNOW SHOULD
AFFECT MAINLY THE SCNTRL/SE FCST AREA. GLOBAL GEM HAS THE HEAVIEST
PCPN WITH TOTALS IN THE 0.75 TO 1 INCH RANGE ACROSS SCNTRL UPPER MI.
GFS/ECMWF MAX OUT AROUND A HALF INCH...THOUGH 00Z ECMWF HAS TRENDED
LESS. THERE WILL PROBABLY BE A BRIEF PERIOD OF LAKE ENHANCED SNOW
ACROSS THE W AND NCNTRL AS SYSTEM PASSES...LEADING TO GREATEST SNOW
ACCUMULATIONS IN THOSE AREAS.
A GENERALLY QUIET PERIOD OF WEATHER IS EXPECTED AFTER THE WEEKEND
SYSTEM. POLAR VORTEX SETTLING FROM THE NPOLE TO ALASKA WILL RESULT
IN INCREASING PACIFIC FLOW ACROSS THE CONUS...SPELLING A WARMING
TREND HERE NEXT WEEK. COULD BE UNSEASONABLY WARM BY THANKSGIVING AS
TROF SWINGING INTO THE WRN CONUS BACKS FLOW SW INTO THE GREAT LAKES.
ECMWF/GFS SHOW 850MB TEMPS PUSHING 8C FOR THANKSGIVING UNDER DRY
AIRMASS...SO IT COULD BE QUITE WARM FOR LATE NOV.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
COLD AIR MOVING ACROSS LAKE SUPERIOR WILL PRODUCE CLOUDS AND LAKE
EFFECT SNOW FOR THE WEST TO NORTHWEST WIND SNOW BELTS TODAY. THIS
WILL LARGELY AFFECT KCMX WITH MAINLY MVFR CIGS/VSBY. HEAVY SNOW
SHOWERS THAT FELL AT KCMX OVERNIGHT HAVE SHIFTED SOUTH OF THE
AIRPORT AS WINDS HAVE BECOME NORTHWEST. GOOD CHANCE THAT AS WINDS
BECOME WESTERLY TODAY COULD SEE ANOTHER ROUND OF HEAVIER SNOW
SHOWERS...BEFORE THE LK EFFECT SHUTS OFF AS WINDS BECOME SOUTHWEST
BY THE EVENING. WENT FOR IFR VSBY IN THE AFTN...BUT CONDITIONS MAY
BRIEFLY FALL TO NEAR AIRPORT MINS IN THE HEAVIEST SNOW SHOWERS.
SOME RISK THAT SOME SNOW SHOWERS MAY WORK INTO KIWD UNTIL WINDS
BECOME MORE SW THIS AFTN. ONLY FLURRIES/MVFR CONDITIONS ARE
EXPECTED. VFR CONDITIONS CONTINUE FOR KSAW AS WRLY WINDS ARE NOT
FAVORABLE FOR ANY LK EFFECT.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
A WEAK TROUGH HANGS ON ACROSS EASTERN LK SUPERIOR MUCH OF TODAY WITH
A CONTINUED POTENTIAL FOR MARGINAL GALE GUSTS OVER SOUTH CENTRAL LK
SUPERIOR. WINDS SLIGHTLY DIMINISH LATER TONIGHT INTO FRIDAY AS WEAK
RIDGE TONIGHT IS FOLLOWED BY A WEST-TO-EAST ORIENTED TROUGH BY
FRIDAY AFTN. SINCE THE TROUGH IS MORE OVER THE LAKE INSTEAD OF TO
THE THE NORTH...WHICH LIMITS PRESSURE FALLS TO ENHANCE STRONGER
WINDS...GALE POTENTIAL FOR FRIDAY HAS LESSENED. LOW PRESSURE OVER
THE PLAINS STILL ON TRACK TO LIFT ACROSS UPR LAKES SATURDAY AFTN AND
SATURDAY EVENING. MODELS HAVE TRENDED WEAKER OVER TIME WITH THE LOW
AND WINDS. UNLESS THERE A FCST OF A DEEPER SYSTEM RETURNS...SEEMS
THERE IS ONLY A LOW RISK OF NORTHERLY GALES WITH THE SYSTEM. HIGH
PRESSURE BUILDS BACK IN FOR EARLY NEXT WEEK...LEADING TO LIGHTER
WINDS BY THAT TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
MIZ001>003-006-084.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ007.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...ROLFSON
DISCUSSION...ROLFSON
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
548 AM EST THU NOV 17 2011
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM
HUDSON BAY S THRU THE MISSISSIPPI VALLEY. WELL UPSTREAM...A DEEP
MIDLEVEL LOW IS DROPPING DOWN THE BRITISH COLUMBIA COAST. OVER THE
NEXT COUPLE OF DAYS...THIS SYSTEM WILL AID TROF DEVELOPMENT OVER THE
WRN CONUS...RESULTING IN DOWNSTREAM FLOW BECOMING SW INTO THE GREAT
LAKES. CLOSER TO HOME...A SHORTWAVE IS SLOWLY MOVING ACROSS UPPER MI
ATTM...SUPPORTING INCREASING LES INTENSITY. JUST UPSTREAM...00Z KINL
SOUNDING SHOWED A FAVORABLE PROFILE FOR LES WITH DEEP MOISTURE UP TO
700MB AND 850MB TEMP OF -15C...RIGHT IN THE MIDDLE OF THE FAVORABLE
TEMP ZONE FOR DENDRITES. CANADIAN RADAR IMAGERY EARLIER IN THE NIGHT
SHOWED A VERY IMPRESSIVE DOMINANT BAND EXTENDING FROM LAKE NIPIGON
DOWN THE ERN SHORE OF LAKE SUPERIOR WHERE N/NE LAND BREEZE OFF
ONTARIO CONVERGED WITH STRONG W FLOW OVER THE LAKE. THAT BAND HAS
GIVEN WAY TO SEVERAL INTENSE SNOW BANDS OVER THE LAKE...AND RADAR
IMAGERY ALMOST SUGGESTS A MESO LOW DEVELOPING NE OF CARIBOU ISLAND.
CONVECTION IS DEEP AS KMQT RADAR CONTINUES TO INDICATE CLOUD TOPS
AROUND 20K FT. OVER THE W...AT LEAST A COUPLE OF DOMINANT BANDS HAVE
BEEN AFFECTING WRN UPPER MI. LAND BREEZE OFF NW WI HAS BEEN
SUPPORTING ONE BAND INTO THE AREA AROUND THE PORCUPINE MOUNTAINS E
TO BERGLAND PER KDLH RADAR. PUBLIC REPORT EARLIER IN THE NIGHT
INDICATED 3 INCHES OF SNOW...AND WEBCAM SUGGESTS POSSIBLY A FEW MORE
INCHES SINCE THEN. ANOTHER DOMINANT BAND HAD BEEN AFFECTING THE AREA
AROUND THE HOUGHTON COUNTY AIRPORT. AWAY FROM W WIND LES...
CLEAR/PARTLY CLOUDY SKIES HAVE BEEN THE RULE ACROSS MUCH OF THE
DOWNSLOPE AREAS OF THE CNTRL INTO ERN FCST AREA DURING THE NIGHT.
&&
.DISCUSSION...
LES SHOULD CONTINUE TO INCREASE OVER THE NEXT SEVERAL HRS GIVEN THE
FAVORABLE AIR MASS PROPERTIES AS INDICATED BY THE 00Z KINL SOUNDING.
SNOW RATES MAY BECOME FAIRLY IMPRESSIVE FOR A WHILE DURING THE
MORNING HRS...AND WILL NEED TO MONITOR FOR POSSIBLE SHORT TERM
UPGRADE OF ADVY TO WARNING OVER SOME PORTION OF THE W IF LOW-LEVEL
CONVERGENCE REMAINS FOCUSED AT ANY ONE LOCATION. TYPICALLY IN W WIND
REGIMES...LAND BREEZE OFF NW WI FORCES CONVERGENCE INTO AN AREA OF
FAR NRN ONTONAGON INTO ADJACENT HOUGHTON COUNTY...OFTEN AROUND TWIN
LAKES. HIGHER RES GUIDANCE SUGGESTS CONVERGENCE WILL REMAIN SET UP A
BIT FARTHER S AS HAS BEEN OCCURRING DURING THE NIGHT FROM THE
PORCUPINE MOUNTAINS TO BERGLAND. REGIONAL GEM AND ESPECIALLY THE
HIRES WRF-ARW HAVE DONE WELL DEPICTING SOME OF THE ACTIVITY OVER THE
WRN U.P. WILL THUS PAINT HIGHEST SNOW TOTALS IN ONTONAGON COUNTY AND
HOUGHTON COUNTY S OF TWIN LAKES. WILL PROBABLY FLIRT WITH 12HR-24HR
WARNING CRITERIA IN A FEW HIGHER TERRAIN LOCATIONS WHERE THE BEST
CONVERGENCE REMAINS NEARLY STATIONARY. TO THE E...W FLOW SO FAR
DURING THE NIGHT HAS KEPT MUCH OF THE LES OFFSHORE OF ERN ALGER/NRN
LUCE. LATEST RADAR TRENDS SHOW INCREASING LES INTENSITY/ORGANIZATION
OVER ERN LAKE SUPERIOR. AS WINDS VEER SLIGHTLY WITH PASSING
SHORTWAVE...ENHANCED CONVERGENCE ZONE SHOULD SHIFT S INTO NE
ALGER/NRN LUCE THIS MORNING. FAVORABLE INSTABILITY/MOISTURE AND
ONGOING HVY SNOW OVER NE/E LAKE SUPERIOR INDICATE POTENTIAL FOR
SIGNIFICANT LES OVER THE NEXT 12HRS. INTERESTING TO NOTE THAT THE
REGIONAL GEM REALLY ENHANCES THE N/NE LAND BREEZE OFF ONTARIO BEHIND
PASSING SHORTWAVE...ENOUGH SO THAT A LAKE NIPIGON ENHANCED HVY SNOW
BAND SHIFTS SW ALL THE WAY TO PICTURED ROCKS. HIGH RES WRF-ARW AND
LOCAL HIGH RES WRF HAVE A SIMILAR SCENARIO...BUT ONLY PUSH
CONVERGENCE ZONE AS FAR SW AS LUCE COUNTY TO POSSIBLY GRAND MARAIS.
STRONGLY FOCUSED CONVERGENCE/LAKE NIPIGON PRECONDITONING AND DEEP
CONVECTIVE/MOIST LAYER (KMQT RADAR INDICATES CLOUD TOPS TO 20K FT)
POINT TO INTENSE SNOWFALL RATES WHEN BANDS SHIFT SW INTO LUCE/NE
ALGER COUNTY. AT THIS POINT...LUCE COUNTY IS MOST LIKELY TO FALL
UNDER THE HEAVIER SNOW...SO WARNING LOOKS ON TRACK THERE. THERE IS
MORE UNCERTAINTY FOR ALGER SINCE BULK OF GUIDANCE DOES NOT SHIFT
CONVERGENCE ZONE AS FAR SW AS REGIONAL GEM/LOCAL HIGH RES WRF. FOR
NOW...WILL LEAVE ADVY FOR ALGER...BUT TRENDS WILL NEED TO MONITORED
CLOSELY THIS MORNING. AWAY FROM LES...EXPECT PARTLY TO MOSTLY CLOUDY
SKIES TODAY...THOUGH WHERE W WIND DOWNSLOPING IS MAXIMIZED IN CNTRL
UPPER MI...THERE MAY BE QUITE A BIT OF SUN THRU THE DAY.
LOW-LEVEL WINDS WILL BEGIN TO BACK LATE AFTN AND THRU TONIGHT...
SHIFTING LES N AND EVENTUALLY OUT OF UPPER MI. LAST OF THE LES
SHOULD PROBABLY EXIT UPPER MI AROUND 06Z TONIGHT. AHEAD OF THE
AMPLIFYING WRN CONUS TROF...A SHORTWAVE WILL STREAK E ALONG
U.S./CANADA BORDER TONIGHT/FRI. WAA REGIME AHEAD OF THE WAVE WILL
ALREADY BE SPREADING INTO THE UPPER GREAT LAKES OVERNIGHT. THERE
REMAINS UNCERTAINTY IN HOW FAR S SATURATION WILL OCCUR IN THE
WAA/STRONG ISENTROPIC REGIME. GIVEN THE STRENGTH OF ASCENT...AT
LEAST LOW POPS ACROSS THE N SEEM REASONABLE. AS WINDS BACK ACROSS
LAKE MICHIGAN...ADDITIONAL LOW-LEVEL MOISTENING SUPPORTS EXTENDING
POPS S ACROSS THE ERN FCST AREA AS WELL.
COLD FRONT ASSOCIATED WITH WAVE WILL DRIFT SE INTO UPPER MI FRI
NIGHT/EARLY SAT AND THEN BECOME STATIONARY AS SHORTWAVE EJECTS FROM
WRN TROF. MODELS CONTINUE TO SHOW GOOD CONTINUITY ON THIS SYSTEM. IF
ANYTHING...THERE APPEARS TO BE A SLIGHT OVERALL MODEL TREND TOWARD A
WEAKER/FLATTER WAVE OVER THE LAST SEVERAL MODEL RUNS. CLUSTERING OF
GUIDANCE IS GOOD WITH ALL INDICATING VERY SIMILAR TRACKS FROM KS
TO THE STRAITS AREA. SINCE SYSTEM WILL BE RELATIVELY FLAT/FAST
MOVING...THIS WILL MOST LIKELY BE AN ADVY TYPE SNOW EVENT SAT
AFTN/NIGHT OVER MUCH OF W AND CNTRL UPPER MI. RAIN/SNOW SHOULD
AFFECT MAINLY THE SCNTRL/SE FCST AREA. GLOBAL GEM HAS THE HEAVIEST
PCPN WITH TOTALS IN THE 0.75 TO 1 INCH RANGE ACROSS SCNTRL UPPER MI.
GFS/ECMWF MAX OUT AROUND A HALF INCH...THOUGH 00Z ECMWF HAS TRENDED
LESS. THERE WILL PROBABLY BE A BRIEF PERIOD OF LAKE ENHANCED SNOW
ACROSS THE W AND NCNTRL AS SYSTEM PASSES...LEADING TO GREATEST SNOW
ACCUMULATIONS IN THOSE AREAS.
A GENERALLY QUIET PERIOD OF WEATHER IS EXPECTED AFTER THE WEEKEND
SYSTEM. POLAR VORTEX SETTLING FROM THE NPOLE TO ALASKA WILL RESULT
IN INCREASING PACIFIC FLOW ACROSS THE CONUS...SPELLING A WARMING
TREND HERE NEXT WEEK. COULD BE UNSEASONABLY WARM BY THANKSGIVING AS
TROF SWINGING INTO THE WRN CONUS BACKS FLOW SW INTO THE GREAT LAKES.
ECMWF/GFS SHOW 850MB TEMPS PUSHING 8C FOR THANKSGIVING UNDER DRY
AIRMASS...SO IT COULD BE QUITE WARM FOR LATE NOV.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
COLD AIR MOVING ACROSS LAKE SUPERIOR WILL PRODUCE CLOUDS AND LAKE
EFFECT SNOW FOR THE WEST TO NORTHWEST WIND SNOW BELTS FOR THE TAF
PERIOD. THIS WILL LARGELY AFFECT KCMX WITH PERIODS OF MVFR CIGS
AND IFR VSBYS. WITH KIWD NOT BEING UNDER FAVORABLE FLOW FOR
SNOW...HAVE LEFT OUT MENTION...BUT DID KEEP MVFR CIGS FOR THE
OVERNIGHT PERIOD FROM MOISTURE CURRENTLY IN NRN MN. KSAW WILL SEE
VFR CONDITIONS THROUGH THE PERIOD. KIWD AND KCMX WILL BECOME VFR AS
SW WINDS WILL PUSH THE LAKE EFFECT CLOUDS OFFSHORE LATE THU
AFTERNOON INTO THU EVENING.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
A WEAK TROUGH HANGS ON ACROSS EASTERN LK SUPERIOR MUCH OF TODAY WITH
A CONTINUED POTENTIAL FOR MARGINAL GALE GUSTS OVER SOUTH CENTRAL LK
SUPERIOR. WINDS SLIGHTLY DIMINISH LATER TONIGHT INTO FRIDAY AS WEAK
RIDGE TONIGHT IS FOLLOWED BY A WEST-TO-EAST ORIENTED TROUGH BY
FRIDAY AFTN. SINCE THE TROUGH IS MORE OVER THE LAKE INSTEAD OF TO
THE THE NORTH...WHICH LIMITS PRESSURE FALLS TO ENHANCE STRONGER
WINDS...GALE POTENTIAL FOR FRIDAY HAS LESSENED. LOW PRESSURE OVER
THE PLAINS STILL ON TRACK TO LIFT ACROSS UPR LAKES SATURDAY AFTN AND
SATURDAY EVENING. MODELS HAVE TRENDED WEAKER OVER TIME WITH THE LOW
AND WINDS. UNLESS THERE A FCST OF A DEEPER SYSTEM RETURNS...SEEMS
THERE IS ONLY A LOW RISK OF NORTHERLY GALES WITH THE SYSTEM. HIGH
PRESSURE BUILDS BACK IN FOR EARLY NEXT WEEK...LEADING TO LIGHTER
WINDS BY THAT TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
MIZ001>003-006-084.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ007.
LAKE SUPERIOR...NONE.
LAKE MICHIGAN...NONE.
&&
$$
SYNOPSIS...ROLFSON
DISCUSSION...ROLFSON
AVIATION...07
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
933 AM EST THU NOV 17 2011
.DISCUSSION...LINGERING AREAS OF LIGHT RAIN OR DRIZZLE OVER SW VA
AND NE TN SHOULD GIVE WAY TO SUNSHINE...AS CLEARING LINE IS ABOUT TO
MOVE ACROSS THE TN VALLEY. CONSIDERED AN UPDATE EARLIER BUT THE
INTENSITY OF THE LINGERING RAIN/DRIZZLE IS VERY LIGHT WITH PROBABLY
NOT MUCH MORE THAN 0.01 INCH. STILL WAITING TO SEE IF ANY REPORTS OF
SNOW COME IN FROM THE HIGHER ELEVATIONS OVER SW VA AND NE TN...WHERE
TEMPS FELL ENOUGH FOR A CHANGE TO SNOW ABOVE 3500 TO 4000 FEET.
WILL DO A TYPICAL MORNING UPDATE OF FORECAST GRIDS AND PRODUCTS BY
11 AM EST. 12Z UPPER AIR PLOTS AND LATEST RUC MODEL SHOW MODERATE
COLD AIR ADVECTION FROM SURFACE TO 850 MBS...WHICH WILL GREATLY
OFFSET THE EFFECTS OF SUNSHINE THIS AFTERNOON. THUS...FORECASTED
HIGHS ARE VERY LIKELY ON TRACK.
OTHERWISE...QUITE A CHILLY NIGHT AHEAD AS SURFACE RIDGE SETTLES OVER
THE REGION.
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
305 PM CST THU NOV 17 2011
.SYNOPSIS...
12Z UA ANALYSIS HAS AN EXTRATROPICAL CYCLONE OVER THE SOUTHEAST
CONUS WITH A NEW SYSTEM MOVING ON SHORE INTO THE PACIFIC NORTHWEST
AND BRITISH COLUMBIA. AN UPPER RIDGE RAN FROM THE SOUTHERN PLAINS
NORTH INTO THE CANADIAN PLAINS. WEAK TROFS WERE OVER THE GREAT LAKES
WITH MORE ACROSS THE ROCKIES. SATELLITE TRENDS THROUGH EARLY
AFTERNOON INDICATE GENERALLY CLEAR SKIES ACROSS THE AREA BUT WAA
CI/CS CLOUDS AHEAD OF THE NEXT SYSTEM WERE MOVING SOUTHEAST FROM THE
NORTHERN PLAINS.
18Z SFC ANALYSIS HAS THE RIDGE AXIS RUNNING FROM MINNESOTA INTO
EASTERN IOWA AND THEN INTO EASTERN TEXAS. A WARM FRONT RAN FROM
NORTHEAST MONTANA INTO CENTRAL NEBRASKA. SEVERAL WEAK TROFS RAN FROM
THE EASTERN GREAT LAKES INTO THE UPPER MIDWEST. DEW POINTS WERE IN
THE TEENS AND 20S ACROSS THE MIDWEST AND PLAINS.
&&
.SHORT TERM...TONIGHT AND FRIDAY...
QUIET AND DRY WX WILL CONTINUE FOR TONIGHT AND FRIDAY. THE PROXIMITY
OF THE SFC RIDGE SHOULD RESULT IN A QUICK DROP OFF IN TEMPERATURES
WITH SUNSET. RETURN WAA DEVELOPS BY MID TO LATE EVENING SO AFTER THE
INITIAL DROP OFF TEMPERATURES SHOULD REMAIN STEADY FOR A WHILE WITH
A VERY SLOW CLIMB EXPECTED AFTER MIDNIGHT. SINCE TEMPERATURES ARE
STRUGGLING TO CLIMB THIS AFTERNOON...MINS TONIGHT SHOULD BE A BIT
LOWER WITH 25 TO 30 COMMON.
ON FRIDAY THE INVERSION WILL START TO MIX OUT AROUND MID MORNING
ALLOWING WINDS TO JUMP. HOWEVER...FCST SOUNDINGS ONLY SUGGEST MIXING
UP TO ABOUT 875MB. THIS LOWER MIXING HEIGHT THEN AFFECTS HOW WARM IT
WILL GET IN SPITE OF THE WAA OCCURRING. THE FACT THAT THE INVERSION
DOES NOT ENTIRELY MIX OUT INDICATES THE HIGHER MOMENTUM AIR WILL
HAVE TROUBLE MIXING DOWN. LOW LEVEL LAPSE RATES FROM THE MODELS ARE
MIXED WITH THEIR RESPECTIVE SOLUTIONS. THE WRF/GFS/ECMWF/SREF SHOW
MARGINALLY STEEP LAPSE RATES ON FRIDAY WHILE THE GEM/UKMET HAVE
QUITE STEEP LOW LEVEL LAPSE RATES. REGARDLESS...IT WILL BE WINDY
WITH GUSTS TO 30 MPH COMMON AND PERHAPS A FEW GUSTS INTO THE MID
30S. SUSTAINED WINDS AND GUSTS ARE EXPECTED TO REMAIN BELOW ADVISORY
CRITERIA SO NO HEADLINE IS EXPECTED.
..08..
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY...
FRIDAY NIGHT THROUGH SATURDAY NIGHT THE MAIN CONCERN IS WITH A STORM
THAT MOVES A SURFACE LOW FROM SOUTHWEST TO NORTHEAST ACROSS IOWA AND
INTO WISCONSIN SATURDAY...MOVING ACROSS THE NORTHWEST CORNER OF THE
CWA. A LARGE FACTOR IN THIS IS THE MOISTURE RETURN THAT WILL BE
BROUGHT INTO THIS SYSTEM. THE GFS IS TYPICALLY TOO AGGRESSIVE WITH
THIS...AND IS PRODUCING LIGHT PRECIPITATION SATURDAY MORNING FROM
WHERE IT SHOULD BE NORTH OF THE FRONT...SMEARED SOUTH ACROSS
IOWA...MISSOURI AND AREAS SOUTH OF THERE YET. THE MOISTURE IS VERY
SHALLOW...LIMITED TO ABOUT 50MB AROUND 850. WHAT USUALLY HAPPENS IN
THIS SITUATION IS STRATUS STREAMS NORTH AHEAD OF THE COLD
FRONT...BUT WE DO NOT GET ANY PRECIPITATION...SO HAVE LEFT THE
FRIDAY NIGHT FORECAST DRY...AND ALL BUT THE NORTHWEST DRY ON
SATURDAY MORNING. AS THE SURFACE LOW ACTUALLY MOVES ACROSS THE AREA
SATURDAY AFTERNOON AND EVENING PRECIPITATION CHANCES LOOK A LITTLE
BETTER...BUT THE BEST LIFT AND MOISTURE CONVERGENCE REMAINS WELL
NORTH OF THE AREA. THE MID LEVEL FRONTOGENESIS BAND WILL STAY WELL
NORTHWEST OF THE REGION...SO AM NOT EXPECTING ANYTHING OVERLY
SIGNIFICANT FOR RAINFALL AMOUNTS IN THIS AREA EITHER. THE STRATUS
SHOULD STREAM INTO THE AREA LATE FRIDAY NIGHT OR EARLY SATURDAY
MORNING...SO OUR MIN TEMPS ARE LIKELY TO OCCUR BETWEEN MIDNIGHT AND
3 AM...BUT THEN RISE ONCE THE STRATUS MOVES IN. THE MID LEVEL FLOW
- AROUND 850MB - SATURDAY AFTERNOON COULD BE AS STRONG AS 50
KTS...BUT WITH THE STRATUS AND THE TEMPERATURE INVERSION
ALOFT KEEPING MIXING DOWN...DO NOT EXPECT STRONGER THAN BREEZY
CONDITIONS AT THE SURFACE TO MATCH WITH THE SURFACE PRESSURE GRADIENT.
HOWEVER...IF WE GET SOME SUNSHINE PEEKING THROUGH...SATURDAY COULD
BE MUCH WINDIER THAN CURRENTLY FORECAST. DESPITE THE CLOUD COVER
THE WINDS WILL ADVECT WARMER TEMPS INTO THE AREA SATURDAY...AND AT
LEAST SOME PEEKS OF SUNSHINE SHOULD ALLOW TEMPS TO GET INTO THE
50S AND LOWER 60S.
SUNDAY AND MONDAY THINGS BECOME QUIET AND COLD AGAIN WITH THE
SURFACE RIDGE BUILDING INTO THE AREA FROM THE NORTHWEST AND BRINGING
MAX TEMPS ONLY IN THE UPPER 30S AND 40S AGAIN. AFTER THE WARMER
TEMPERATURES ON SATURDAY DROPPING BACK INTO THE 30S IS GOING TO BE A
SHOCK- AGAIN.
TUESDAY AND TUESDAY NIGHT THE MODELS DIVERGE SIGNIFICANTLY. THE
ECMWF BRINGS A FAIRLY STRONG SHORTWAVE ACROSS THE SOUTHERN CONUS AS
COMPARED TO THE GFS. BOTH HAVE BEEN RELATIVELY CONSISTENT WITH THIS
SYSTEM...THOUGH THE ECMWF HAS BEEN ADJUSTING HOW FAR NORTH IT BRINGS
THE SYSTEM SOMEWHAT. THUS...HAVE GONE WITH A MIDDLE OF THE ROAD
FORECAST WITH SOME POPS ACROSS THE SOUTH AND COLDER THAN NORMAL
TEMPERATURES...AND WE WILL HAVE TO WAIT ANOTHER DAY OR TWO BEFORE
THE MODELS CONVERGE ON SOMETHING. ..LE..
&&
.AVIATION...
VFR WX WILL BE SEEN THROUGH 00Z/19 AND LIKELY THROUGH 12Z/19 WITH
ONLY MID AND HIGH LEVEL CLOUDS. CURRENT RUC TRENDS SUPPORT A THREAT
OF LLWS STARTING IN THE 04Z-07Z/18 TIME FRAME. A LOW LEVEL JET DVLPS
AFT 00Z/18 AND REACHES PEAK INTENSITY ARND 50 KTS 06Z-12Z/18. LLWS
WITH SHEAR VALUES ARND 30 KTS ARE EXPECTED TO DVLP IN THE 1.8-2.0KFT
AGL LAYER. SOUNDINGS SUGGEST A SUDDEN JUMP IN WIND SPEED IN THE
1.0-1.5KFT AGL LAYER BUT SHEAR VALUES SHOULD REMAIN UNDER 20 KTS.
INVERSION STARTS MIXING OUT AT 15Z/18 WITH LOW LVL TURBULENCE DVLPG.
..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
252 PM EST THU NOV 17 2011
.SYNOPSIS...
EASTBOUND COLD HIGH PRESSURE WILL PROVIDE CLEARING OVERNIGHT AND
SUNSHINE FRIDAY AND SATURDAY. A COLD FRONT, COMING EAST FROM THE
ROCKIES, WILL BRING SOME SHOWERS SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
PER RECENT RADAR, SATELLITE, AND SURFACE DATA AND HRRR MODEL
OUTPUT, EXPECT ISOLATED LIGHT SNOW SHOWERS TO REMAIN CONFINED TO
THE I-80 CORRIDOR AND MOUNTAINS THROUGH EVENING. THEN EXPECT SOME
CLEARING LATE TONIGHT.
NAM MODEL PROFILES SUGGEST SURFACE WINDS CAN GUST TO 30 TO 35
MPH, BEFORE DYING DOWN LATE.
LOWS TONIGHT CAN BE 7 TO 10 DEGREES COLDER THAN NORMAL, PER CONSENSUS
OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
BLEND OF RECENT SREF MODEL OUTPUT CONTINUES TO SHOW EASTBOUND HIGH
PRESSURE WILL PROVIDE DRY CONDITIONS AND MAINLY CLEAR SKIES
FRIDAY AND SATURDAY.
A COLD FRONT, COMING EAST FROM THE ROCKY MOUNTAINS, WILL BRING
SCATTERED SHOWERS THROUGH THE UPPER OHIO VALLEY MAINLY DURING THE DAYTIME
HOURS OF SUNDAY, AS RECENT OPERATIONAL MODELS SUCH AS THE GFS AND
NAM HAVE BEEN A COUPLE HOURS WITH THE ONSET OF THE SHOWERS.
PER RECENT BLEND OF GFS AND NAM MOS, FORECASTED LOWS THURSDAY
NIGHT AND HIGHS FRIDAY TO BE STILL A COUPLE DEGREES COLDER THAN
NORMAL. HIGHS SATURDAY ARE EXPECTED TO MODERATE TO PERHAPS A
COUPLE DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
LOWER THAN AVERAGE CONFIDENCE FOR THE EXTENDED FORECAST. ALTHOUGH
THE GFS AND ECMWF AGREE THAT SUNDAY/S COLD FRONT WILL STALL OUT
AFTER MOVING SOUTH OF THE MASON-DIXON LINE...THERE IS DISAGREEMENT
BETWEEN THE MODELS AS TO HOW THE FRONT WILL SHIFT OVER TIME AND
WHETHER ITS INFLUENCE WILL BE FELT NORTH OF THE PA-WV BORDER. AS A
RESULT...HAVE GENERALLY GONE WITH SLIGHT CHANCE POPS TO THE NORTH
AND CHANCE POPS TO THE SOUTH.
BY THE END OF THE PERIOD...THERE IS SOME MODEL CONSENSUS THAT THE
FRONT WILL PUSH OUT TO SEA AND BE REPLACED BY HIGH PRESSURE...
ALTHOUGH THE 00Z ECMWF BRINGS A MUCH STRONGER SYSTEM IN. HPC
STATES THAT THE ECMWF ENSEMBLE SHOWS THE DETERMINISTIC ECMWF
SOLUTION IS UNLIKELY.
INITIAL FORECAST FOR THANKSGIVING...PARTLY CLOUDY...DRY...AND HIGHS
IN THE 40S.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AS BREAKS APPEAR IN MID-LEVEL DECK THIS AFTERNOON...GUSTS UP TO 25
KTS WILL DEVELOP FROM WEST TO EAST. SOME GUIDANCE INDICATES THAT
THESE GUSTS COULD PERSIST INTO THE EVENING...BUT HAVE DECIDED TO END
MENTION OF GUSTS JUST AFTER SUNSET.
HAVE INCLUDED TEMPO FOR AFTERNOON SNOW SHOWERS AT FKL...BUT THINK
THAT MOST SNOW SHOWERS SHOULD REMAIN NORTH OF THE TERMINAL. LOW
CLOUDS MAY REMAIN OVERNIGHT NEAR INTERSTATE 80 AND THE
RIDGES...BUT THINK THAT OTHER LOCATIONS SHOULD CLEAR OUT.
CONDITIONS WILL BE TOO DRY FOR FOG DEVELOPMENT OVERNIGHT.
WINDS WILL SLOWLY BACK TO THE SOUTHWEST OVERNIGHT INTO FRIDAY
MORNING...WITH GUSTS TO 15 KT INCLUDED IN THE 30 HOUR PIT TAF.
OUTLOOK...FRIDAY THROUGH TUESDAY...
HIGH PRESSURE WILL KEEP VFR CONDITIONS IN THE FORECAST THROUGH
SATURDAY NIGHT. BY SUNDAY...A COLD FRONT WILL MOVE IN FROM THE
WEST...BRINGING THE POTENTIAL FOR RESTRICTIONS IN SHOWERS. WITH THE
FRONT STALLING NEAR THE REGION...UNSETTLED WEATHER IS EXPECTED TO
REMAIN POSSIBLE THROUGH TUESDAY.
PER RECENT SURFACE AND SATELLITE DATA, EXPECT VFR COLD-POOL
STRATOCUMULUS TO REMAIN ACROSS THE UPPER OHIO VALLEY INTO EARLY
EVENING. BRIEF MVFR RESTRICTIONS ARE POSSIBLE MAINLY AT KFKL AND
KDUJ DURING THIS AFTERNOON DUE TO SCATTERED LAKE EFFECT SNOW
SHOWERS. SURFACE WINDS CAN GUST TO 25 KTS.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
HIGH PRESSURE WILL BUILD AND PROVIDE VFR TO THE UPPER OHIO REGION
THROUGH SATURDAY. THEREAFTER...THE CHANCE FOR RAIN AND RESTRICTIONS
WILL INCREASE WITH THE APPROACH AND PASSAGE OF ANOTHER COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1152 AM EST THU NOV 17 2011
.SYNOPSIS...
COLD HIGH PRESSURE WILL MOVE ACROSS THE OHIO VALLEY TODAY AND
FRIDAY. ISOLATED LAKE EFFECT SNOW SHOWERS CAN OCCUR ACROSS
NORTHWEST PENNSYLVANIA AND THE APPALACHIAN MOUNTAINS INTO TONIGHT.
EXPECT MORE SUNSHINE FRIDAY AND SATURDAY. A PASSING MIDWEST COLD
FRONT WILL BRING SCATTERED RAIN SHOWERS LATE SATURDAY NIGHT AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
PER RECENT RADAR, SATELLITE, AND SURFACE DATA AND HRRR MODEL
OUTPUT, EXPECT MAINLY JUST ISOLATED LIGHT SNOW SHOWERS ACROSS THE
I-80 CORRIDOR AND MOUNTAINS THROUGH TONIGHT. ELSEWHERE MAINLY
SCATTERED CLOUDS THIS AFTERNOON INTO EVENING, WITH CLEARING LATE
TONIGHT.
NAM MODEL PROFILES SUGGEST SURFACE WINDS CAN GUST TO 30
TO 35 MPH.
COLD ADVECTION ALOFT WILL PREVENT TEMPERATURES FROM CLIMBING MUCH THIS
AFTERNOON. LOWS TONIGHT CAN BE 7 TO 10 DEGREES COLDER THAN NORMAL. SPECIFIC
VALUES FORECASTED USING CONSENSUS OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL DOMINATE FRIDAY INTO SATURDAY WITH A DRY
CONDITIONS AND A GRADUAL MODERATING OF TEMPERATURES ESPECIALLY
SATURDAY WHEN HIGHS WILL REACH ABOVE NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
PROGRESSIVE PATTERN IS FORECAST OVER THE GREAT LAKES AND UPPER
OHIO REGIONS FOR THE LONG TERM PERIOD WITH RIDGING OVER THE GULF
AND TROUGHING OVER THE PAC NW/WEST COAST. SHORTWAVES WITHIN THE
FAST FLOW WILL DEFINE THE SENSIBLE WEATHER FOR THE REGION...HENCE
WILL BE DIFFICULT TO TIME.
HAVE RAISED POPS TO LIKELY FOR SUNDAY FOR THE APPROACH AND
PASSAGE OF A COLD FRONT ASSOCIATED WITH LOW PRESSURE PROGGED TO
RACE ACROSS THE GREAT LAKES. THEREAFTER...FORECAST WAS BASED
GFS/ECMWF BLENDED-TIMING OF DISTURBANCES AND HPC TEMPERATURE
GUIDANCE WHICH IS REASONABLY AT...OR SLIGHTLY ABOVE THE SEASONAL
NORMALS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
PER RECENT SURFACE AND SATELLITE DATA, EXPECT VFR COLD-POOL STRATOCUMULUS
TO REMAIN ACROSS THE UPPER OHIO VALLEY INTO EARLY EVENING. BRIEF
MVFR RESTRICTIONS ARE POSSIBLE MAINLY AT KFKL AND KDUJ DURING
THIS AFTERNOON DUE TO SCATTERED LAKE EFFECT SNOW SHOWERS. SURFACE
WINDS CAN GUST TO 25 KTS.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
HIGH PRESSURE WILL BUILD AND PROVIDE VFR TO THE UPPER OHIO REGION
THROUGH SATURDAY. THEREAFTER...THE CHANCE FOR RAIN AND RESTRICTIONS
WILL INCREASE WITH THE APPROACH AND PASSAGE OF ANOTHER COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
315 PM EST THU NOV 17 2011
LATEST UPDATE...ALL BUT AVIATION...
.SYNOPSIS...(315 PM EST THU NOV 17 2011)
THE LAKE EFFECT SNOW SHOWERS WILL GRADUALLY DIMINISH THIS EVENING.
HIGH PRESSURE OVER THE MIDDLE MISSISSIPPI VALLEY WILL STRENGTHEN AS
IT BUILDS EAST INTO THE CENTRAL APPALACHIANS ON FRIDAY. A GUSTY
SOUTHWESTERLY FLOW WILL SETUP HERE IN LOWER MICHIGAN DURING THE DAY
AND PERSIST INTO SATURDAY. A COLD FRONT WILL SLIP SOUTHEASTWARD
THROUGH THE REGION SATURDAY NIGHT PRODUCING SOME RAIN SHOWERS.
COOLER AIR WILL THEN FILTER IN FOR THE REMAINDER OF THE WEEKEND.
&&
.SHORT TERM...(315 PM EST THU NOV 17 2011)
(TONIGHT THROUGH SATURDAY NIGHT)...
THE MAIN CHALLENGE IN THE SHORT TERM DEALS WITH THE WIND GUSTS ON
FRIDAY.
BUFKIT OVERVIEWS SHOW MIXING HEIGHTS TAPPING INTO THE 40
KNOT WIND RANGE ALONG THE LAKESHORE DURING THE DAY ON FRIDAY. ALSO
FSL RUC DATA SUGGESTS WINDS OVER 40 KNOTS MOVING INLAND DURING THE
DAY. PROFILER DATA FROM THE LOWER PLAINS SHOWS THE LOW
LEVEL JET FORMING AND IT IS ALREADY ABOUT 10 KNOTS STRONGER THAN
FORECASTED. WILL ISSUE A WIND ADVISORY FOR FRIDAY FROM 12Z TO 00Z.
MIXING HEIGHTS LOWER DURING THE EVENING AND THAT SHOULD ALLOW FOR
THE WIND TO DECREASE.
THE TIMING OF THE SHOWERS LATER SATURDAY INTO SATURDAY LOOKS GOOD.
I DID DELAY THE SHOWERS SLIGHTLY GIVEN THE SOMEWHAT SLOWER TREND OF
THE FRONTAL PASSAGE. AS A RESULT I TOOK OUT THE MENTION OF SHOWERS
PRIOR TO 18Z SAT.
A DECENT WARMUP IS IN STORE FOR THE REGION ON SATURDAY. LOW LEVEL
THERMAL PROFILES SUPPORT HIGHS TOPPING 50 DEGREES.
&&
.LONG TERM...(315 PM EST THU NOV 17 2011)
(SUNDAY THROUGH THANKSGIVING DAY)
THE LONG TERM PORTION OF THE FCST LOOKS RATHER TRANQUIL...ESPECIALLY
BY MID-LATE NOVEMBER STANDARDS FOR MICHIGAN. WE WILL HAVE TO WATCH A
POSSIBLE SYSTEM THAT COULD STILL IMPACT AT LEAST A PORTION OF THE
AREA TUE INTO TUE NIGHT.
FRONTAL SYSTEM MOVING THROUGH SAT/SAT NIGHT STILL APPEARS TO JUST
CLEAR THE CWFA BY 12Z SUN. DRY NE FLOW AROUND THE INCOMING SFC RIDGE
AND NOT SO COLD TEMPS /H850 TEMPS 0 TO -2C/ WILL BRING QUIET AND
SEASONABLE TEMPS TO THE AREA. WE ARE EXPECTING THIS HIGH TO RULE
ACROSS THE AREA AT LEAST THROUGH MON. FOR NOW...WE ARE DISCOUNTING
THE 12Z GFS BRINGING LIGHT PCPN TO THE AREA. IT SEEMS TO BE TRYING
TO PHASE SRN STREAM MOISTURE WITH A WEAK NRN STREAM TROUGH. THE
SETUP LOOKS OVERDONE WITH MOISTURE THIS FAR NORTH AND NOT FAVORABLE
FOR PCPN ON MON FOR NOW.
THE TRENDS IN THE MODELS ARE TO HAVE THE SYSTEM FOR TUE/WED A LITTLE
FURTHER NORTH THAN WAS EXPECTED 24 HOURS AGO. WE CAN NOT DISCOUNT
THIS IDEA EXPECTING IT MAY BE A LITTLE STRONGER THAN WHAT IS BEING
SAMPLED NOW. HOWEVER UNLESS THERE IS GOOD PHASING BETWEEN THE TWO
STREAMS...IT SHOULD CONTINUE TO MAINLY MISS THE AREA. THE 00Z EURO
WAS QUITE THE OUTLIER WITH A CLOSED NRN STREAM LOW PHASING WITH THE
SRN STREAM...AND BRINGING A LOT OF PCPN TO THE AREA TUE/WED. THE NEW
EURO HAS BACKED AWAY FROM THAT THINKING...AND IS CLOSER TO THE
ENSEMBLES. IN COORDINATION WITH SURROUNDING OFFICES...WE HAVE ADDED
A SMALL CHC OF PCPN TUE AND TUE NIGHT DOWN SOUTH FOR NOW...AND WILL
CONTINUE TO MONITOR THE TRENDS.
ALL OF THE MODELS HAVE A FAIRLY GOOD RIDGE THEN BUILDING OVER THE
AREA FOR WED AND THANKSGIVING DAY AS ANOTHER STRONG TROUGH TAKES
SHAPE ALONG THE WEST COAST. THIS SHOULD ALLOW FOR MORE SEASONABLE TO
SLIGHTLY ABOVE AVERAGE TEMPS FOR NOVEMBER ALONG WITH DRY CONDITIONS
FOR THE FIRST PART OF THE HOLIDAY TRAVEL PERIOD FOR MICHIGAN.
&&
.AVIATION...(1245 PM EST THU NOV 17 2011)
LAKE EFFECT TRENDS AND GUSTY WINDS ARE THE MAIN ITEMS OF INTEREST
WITH THIS SET OF FCSTS.
LAKE EFFECT FLURRIES/SNOW SHOWERS ARE AFFECTING MOST OF THE AREA
EARLY THIS AFTERNOON...HOWEVER THE IMPACTS ARE NOT SIGNIFICANT. MOST
OF THE CIGS AND VSBYS ARE REMAINING VFR WITH SOME ISOLATED MVFR
PRESENT. THE BEST SNOW SHOWERS ARE ACTUALLY DISPLACED INLAND
SOME...LIKELY DUE TO SOME DIURNAL ENHANCEMENT. CONDITIONS ARE
EXPECTED TO BEGIN TO IMPROVE IN THE NEXT 2-4 HOURS AS THE UPPER WAVE
BEGINS TO MOVE AWAY. GUSTS TO 25 KNOTS THIS AFTERNOON WILL DIMINISH
AROUND 23-01Z.
LAKE CLOUDS WILL LIKELY HANG ON THROUGH A GOOD PORTION OF THE
EVENING. RIDGING TAKES HOLD LATE THIS EVENING...AND A SURGE OF EVEN
DRIER AIR MOVES IN AT THAT TIME. CLOUDS WILL LIKELY DISSIPATE ACROSS
THE FAR EAST FIRST...AND WRN SITES WILL BE LAST TO CLEAR OUT DUE TO
THE PROXIMITY OF THE LAKE.
ONLY MID CLOUDS ARE EXPECTED THEN LATE TONIGHT AND ON FRI. WINDS
WILL PICK UP PRIOR TO DAYBREAK AT KMKG WITH BETTER MIXING OFF OF THE
LAKE. WINDS WILL INCREASE SOME AT KAZO AND KGRR PRIOR TO DAYBREAK.
SUSTAINED WINDS OF 20-25 KNOTS ARE LIKELY...WITH GUSTS TO 35 KNOTS
AS DIURNAL MIXING TAKES PLACE. SOME GUSTS TO 40 KNOTS ARE NOT OUT OF
THE QUESTION..
&&
.MARINE...(315 PM EST THU NOV 17 2011)
THE ARRIVAL OF A LOW LEVEL JET COUPLED WITH INCREASED MIXING ON
FRIDAY SUPPORTS KEEPING THE GALE WARNING FOR FRIDAY. MIXING
HEIGHTS SUGGEST THE NEARSHORE ZONES WILL REACH INTO THE 40 KNOT
RANGE OF WINDS FRIDAY. THE LOW LEVEL JET AND INCREASED MIXING
PERSISTS THROUGH 00Z SAT...THUS I WILL KEEP THE WARNING GOING
THROUGH MUCH OF THE NIGHT.
&&
.HYDROLOGY...(315 PM EST WED NOV 16 2011)
ANY QPF THROUGH THE PERIOD IS FORECASTED TO BE RELATIVELY LIGHT. AS
A RESULT... NO HYDRO ISSUES ANTICIPATED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY FOR THE LAKESHORE COUNTIES FRIDAY.
LM...SMALL CRAFT ADVISORY ALL NEARSHORE ZONES THROUGH TONIGHT.
GALE WARNING FRIDAY INTO FRIDAY NIGHT ALL NEARSHORE ZONES.
&&
$$
SYNOPSIS: MJS
SHORT TERM: MJS
LONG TERM: NJJ
AVIATION: NJJ
MARINE: MJS
HYDROLOGY: MJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1240 PM EST THU NOV 17 2011
UPDATED AVIATION DISCUSSION FOR 18Z TAFS
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM
HUDSON BAY S THRU THE MISSISSIPPI VALLEY. WELL UPSTREAM...A DEEP
MIDLEVEL LOW IS DROPPING DOWN THE BRITISH COLUMBIA COAST. OVER THE
NEXT COUPLE OF DAYS...THIS SYSTEM WILL AID TROF DEVELOPMENT OVER THE
WRN CONUS...RESULTING IN DOWNSTREAM FLOW BECOMING SW INTO THE GREAT
LAKES. CLOSER TO HOME...A SHORTWAVE IS SLOWLY MOVING ACROSS UPPER MI
ATTM...SUPPORTING INCREASING LES INTENSITY. JUST UPSTREAM...00Z KINL
SOUNDING SHOWED A FAVORABLE PROFILE FOR LES WITH DEEP MOISTURE UP TO
700MB AND 850MB TEMP OF -15C...RIGHT IN THE MIDDLE OF THE FAVORABLE
TEMP ZONE FOR DENDRITES. CANADIAN RADAR IMAGERY EARLIER IN THE NIGHT
SHOWED A VERY IMPRESSIVE DOMINANT BAND EXTENDING FROM LAKE NIPIGON
DOWN THE ERN SHORE OF LAKE SUPERIOR WHERE N/NE LAND BREEZE OFF
ONTARIO CONVERGED WITH STRONG W FLOW OVER THE LAKE. THAT BAND HAS
GIVEN WAY TO SEVERAL INTENSE SNOW BANDS OVER THE LAKE...AND RADAR
IMAGERY ALMOST SUGGESTS A MESO LOW DEVELOPING NE OF CARIBOU ISLAND.
CONVECTION IS DEEP AS KMQT RADAR CONTINUES TO INDICATE CLOUD TOPS
AROUND 20K FT. OVER THE W...AT LEAST A COUPLE OF DOMINANT BANDS HAVE
BEEN AFFECTING WRN UPPER MI. LAND BREEZE OFF NW WI HAS BEEN
SUPPORTING ONE BAND INTO THE AREA AROUND THE PORCUPINE MOUNTAINS E
TO BERGLAND PER KDLH RADAR. PUBLIC REPORT EARLIER IN THE NIGHT
INDICATED 3 INCHES OF SNOW...AND WEBCAM SUGGESTS POSSIBLY A FEW MORE
INCHES SINCE THEN. ANOTHER DOMINANT BAND HAD BEEN AFFECTING THE AREA
AROUND THE HOUGHTON COUNTY AIRPORT. AWAY FROM W WIND LES...
CLEAR/PARTLY CLOUDY SKIES HAVE BEEN THE RULE ACROSS MUCH OF THE
DOWNSLOPE AREAS OF THE CNTRL INTO ERN FCST AREA DURING THE NIGHT.
&&
.DISCUSSION...
LES SHOULD CONTINUE TO INCREASE OVER THE NEXT SEVERAL HRS GIVEN THE
FAVORABLE AIR MASS PROPERTIES AS INDICATED BY THE 00Z KINL SOUNDING.
SNOW RATES MAY BECOME FAIRLY IMPRESSIVE FOR A WHILE DURING THE
MORNING HRS...AND WILL NEED TO MONITOR FOR POSSIBLE SHORT TERM
UPGRADE OF ADVY TO WARNING OVER SOME PORTION OF THE W IF LOW-LEVEL
CONVERGENCE REMAINS FOCUSED AT ANY ONE LOCATION. TYPICALLY IN W WIND
REGIMES...LAND BREEZE OFF NW WI FORCES CONVERGENCE INTO AN AREA OF
FAR NRN ONTONAGON INTO ADJACENT HOUGHTON COUNTY...OFTEN AROUND TWIN
LAKES. HIGHER RES GUIDANCE SUGGESTS CONVERGENCE WILL REMAIN SET UP A
BIT FARTHER S AS HAS BEEN OCCURRING DURING THE NIGHT FROM THE
PORCUPINE MOUNTAINS TO BERGLAND. REGIONAL GEM AND ESPECIALLY THE
HIRES WRF-ARW HAVE DONE WELL DEPICTING SOME OF THE ACTIVITY OVER THE
WRN U.P. WILL THUS PAINT HIGHEST SNOW TOTALS IN ONTONAGON COUNTY AND
HOUGHTON COUNTY S OF TWIN LAKES. WILL PROBABLY FLIRT WITH 12HR-24HR
WARNING CRITERIA IN A FEW HIGHER TERRAIN LOCATIONS WHERE THE BEST
CONVERGENCE REMAINS NEARLY STATIONARY. TO THE E...W FLOW SO FAR
DURING THE NIGHT HAS KEPT MUCH OF THE LES OFFSHORE OF ERN ALGER/NRN
LUCE. LATEST RADAR TRENDS SHOW INCREASING LES INTENSITY/ORGANIZATION
OVER ERN LAKE SUPERIOR. AS WINDS VEER SLIGHTLY WITH PASSING
SHORTWAVE...ENHANCED CONVERGENCE ZONE SHOULD SHIFT S INTO NE
ALGER/NRN LUCE THIS MORNING. FAVORABLE INSTABILITY/MOISTURE AND
ONGOING HVY SNOW OVER NE/E LAKE SUPERIOR INDICATE POTENTIAL FOR
SIGNIFICANT LES OVER THE NEXT 12HRS. INTERESTING TO NOTE THAT THE
REGIONAL GEM REALLY ENHANCES THE N/NE LAND BREEZE OFF ONTARIO BEHIND
PASSING SHORTWAVE...ENOUGH SO THAT A LAKE NIPIGON ENHANCED HVY SNOW
BAND SHIFTS SW ALL THE WAY TO PICTURED ROCKS. HIGH RES WRF-ARW AND
LOCAL HIGH RES WRF HAVE A SIMILAR SCENARIO...BUT ONLY PUSH
CONVERGENCE ZONE AS FAR SW AS LUCE COUNTY TO POSSIBLY GRAND MARAIS.
STRONGLY FOCUSED CONVERGENCE/LAKE NIPIGON PRECONDITONING AND DEEP
CONVECTIVE/MOIST LAYER (KMQT RADAR INDICATES CLOUD TOPS TO 20K FT)
POINT TO INTENSE SNOWFALL RATES WHEN BANDS SHIFT SW INTO LUCE/NE
ALGER COUNTY. AT THIS POINT...LUCE COUNTY IS MOST LIKELY TO FALL
UNDER THE HEAVIER SNOW...SO WARNING LOOKS ON TRACK THERE. THERE IS
MORE UNCERTAINTY FOR ALGER SINCE BULK OF GUIDANCE DOES NOT SHIFT
CONVERGENCE ZONE AS FAR SW AS REGIONAL GEM/LOCAL HIGH RES WRF. FOR
NOW...WILL LEAVE ADVY FOR ALGER...BUT TRENDS WILL NEED TO MONITORED
CLOSELY THIS MORNING. AWAY FROM LES...EXPECT PARTLY TO MOSTLY CLOUDY
SKIES TODAY...THOUGH WHERE W WIND DOWNSLOPING IS MAXIMIZED IN CNTRL
UPPER MI...THERE MAY BE QUITE A BIT OF SUN THRU THE DAY.
LOW-LEVEL WINDS WILL BEGIN TO BACK LATE AFTN AND THRU TONIGHT...
SHIFTING LES N AND EVENTUALLY OUT OF UPPER MI. LAST OF THE LES
SHOULD PROBABLY EXIT UPPER MI AROUND 06Z TONIGHT. AHEAD OF THE
AMPLIFYING WRN CONUS TROF...A SHORTWAVE WILL STREAK E ALONG
U.S./CANADA BORDER TONIGHT/FRI. WAA REGIME AHEAD OF THE WAVE WILL
ALREADY BE SPREADING INTO THE UPPER GREAT LAKES OVERNIGHT. THERE
REMAINS UNCERTAINTY IN HOW FAR S SATURATION WILL OCCUR IN THE
WAA/STRONG ISENTROPIC REGIME. GIVEN THE STRENGTH OF ASCENT...AT
LEAST LOW POPS ACROSS THE N SEEM REASONABLE. AS WINDS BACK ACROSS
LAKE MICHIGAN...ADDITIONAL LOW-LEVEL MOISTENING SUPPORTS EXTENDING
POPS S ACROSS THE ERN FCST AREA AS WELL.
COLD FRONT ASSOCIATED WITH WAVE WILL DRIFT SE INTO UPPER MI FRI
NIGHT/EARLY SAT AND THEN BECOME STATIONARY AS SHORTWAVE EJECTS FROM
WRN TROF. MODELS CONTINUE TO SHOW GOOD CONTINUITY ON THIS SYSTEM. IF
ANYTHING...THERE APPEARS TO BE A SLIGHT OVERALL MODEL TREND TOWARD A
WEAKER/FLATTER WAVE OVER THE LAST SEVERAL MODEL RUNS. CLUSTERING OF
GUIDANCE IS GOOD WITH ALL INDICATING VERY SIMILAR TRACKS FROM KS
TO THE STRAITS AREA. SINCE SYSTEM WILL BE RELATIVELY FLAT/FAST
MOVING...THIS WILL MOST LIKELY BE AN ADVY TYPE SNOW EVENT SAT
AFTN/NIGHT OVER MUCH OF W AND CNTRL UPPER MI. RAIN/SNOW SHOULD
AFFECT MAINLY THE SCNTRL/SE FCST AREA. GLOBAL GEM HAS THE HEAVIEST
PCPN WITH TOTALS IN THE 0.75 TO 1 INCH RANGE ACROSS SCNTRL UPPER MI.
GFS/ECMWF MAX OUT AROUND A HALF INCH...THOUGH 00Z ECMWF HAS TRENDED
LESS. THERE WILL PROBABLY BE A BRIEF PERIOD OF LAKE ENHANCED SNOW
ACROSS THE W AND NCNTRL AS SYSTEM PASSES...LEADING TO GREATEST SNOW
ACCUMULATIONS IN THOSE AREAS.
A GENERALLY QUIET PERIOD OF WEATHER IS EXPECTED AFTER THE WEEKEND
SYSTEM. POLAR VORTEX SETTLING FROM THE NPOLE TO ALASKA WILL RESULT
IN INCREASING PACIFIC FLOW ACROSS THE CONUS...SPELLING A WARMING
TREND HERE NEXT WEEK. COULD BE UNSEASONABLY WARM BY THANKSGIVING AS
TROF SWINGING INTO THE WRN CONUS BACKS FLOW SW INTO THE GREAT LAKES.
ECMWF/GFS SHOW 850MB TEMPS PUSHING 8C FOR THANKSGIVING UNDER DRY
AIRMASS...SO IT COULD BE QUITE WARM FOR LATE NOV.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
COLD AIR MOVING ACROSS LAKE SUPERIOR WILL PRODUCE CLOUDS AND LAKE
EFFECT SNOW FOR THE WEST TO NORTHWEST WIND SNOW BELTS TODAY. THIS
WILL LARGELY AFFECT KCMX WITH MAINLY MVFR CIGS/VSBY. HEAVY SNOW
SHOWERS THAT FELL AT KCMX OVERNIGHT HAVE SHIFTED SOUTH OF THE
AIRPORT AS WINDS HAVE BECOME NORTHWEST. GOOD CHANCE THAT AS WINDS
BECOME WESTERLY THIS AFTERNOON COULD SEE ANOTHER ROUND OF HEAVIER
SNOW SHOWERS...BEFORE THE LK EFFECT SHUTS OFF AS WINDS BECOME
SOUTHWEST BY THE EVENING. WENT FOR IFR VSBY THIS AFTN...BUT
CONDITIONS MAY BRIEFLY FALL TO NEAR AIRPORT MINS IN THE HEAVIEST
SNOW SHOWERS.
SOME RISK THAT SOME SNOW SHOWERS MAY WORK INTO KIWD UNTIL WINDS
BECOME MORE SW LATER THIS AFTN. ONLY FLURRIES/MVFR CONDITIONS ARE
EXPECTED. VFR CONDITIONS CONTINUE FOR KSAW AS WRLY WINDS ARE NOT
FAVORABLE FOR ANY LK EFFECT.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
A WEAK TROUGH HANGS ON ACROSS EASTERN LK SUPERIOR MUCH OF TODAY WITH
A CONTINUED POTENTIAL FOR MARGINAL GALE GUSTS OVER SOUTH CENTRAL LK
SUPERIOR. WINDS SLIGHTLY DIMINISH LATER TONIGHT INTO FRIDAY AS WEAK
RIDGE TONIGHT IS FOLLOWED BY A WEST-TO-EAST ORIENTED TROUGH BY
FRIDAY AFTN. SINCE THE TROUGH IS MORE OVER THE LAKE INSTEAD OF TO
THE THE NORTH...WHICH LIMITS PRESSURE FALLS TO ENHANCE STRONGER
WINDS...GALE POTENTIAL FOR FRIDAY HAS LESSENED. LOW PRESSURE OVER
THE PLAINS STILL ON TRACK TO LIFT ACROSS UPR LAKES SATURDAY AFTN AND
SATURDAY EVENING. MODELS HAVE TRENDED WEAKER OVER TIME WITH THE LOW
AND WINDS. UNLESS THERE A FCST OF A DEEPER SYSTEM RETURNS...SEEMS
THERE IS ONLY A LOW RISK OF NORTHERLY GALES WITH THE SYSTEM. HIGH
PRESSURE BUILDS BACK IN FOR EARLY NEXT WEEK...LEADING TO LIGHTER
WINDS BY THAT TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
MIZ001>003-006-084.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ007.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...ROLFSON
DISCUSSION...ROLFSON
AVIATION...TITUS
MARINE...JLA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1031 AM CST THU NOV 17 2011
.DISCUSSION...
ONLY MAJOR CHANGE FOR THE MORNING UPDATE WAS TO PULL POPS FOR THIS
AFTERNOON OVER THE NORTHWESTERN COUNTIES. LATEST NAM AND HRRR RUNS
DO NOT HAVE ANY PRECIP MOVING IN UNTIL AFTER 00Z. A FEW LIGHT
RADAR RETURNS HAVE SHOWN UP IN WESTERN ND...BUT NOTHING HAS
REACHED THE GROUND SO FAR. THINK THAT ANY SNOW WILL HOLD OFF UNTIL
AFTER 00Z TONIGHT AS THE SFC LOW MOVES OUT INTO THE PLAINS. MADE A
FEW MINOR TWEAKS TO CLOUDS AND TEMPERATURES TO REFLECT CURRENT
TRENDS...BUT CONTINUED TO KEEP HIGHS IN THE LOW 20S UNDER THE SNOW
COVER WITH WARMER TEMPS ELSEWHERE.
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGHOUT THE PERIOD AS CIRRUS
INCREASES OVER THE REGION. LIGHT AND VARIABLE WINDS THIS MORNING
WILL BEGIN TO INCREASE OUT OF THE SOUTHEAST AT AROUND 12KTS BY
LATE AFTERNOON. WINDS WILL SHIFT TO THE WEST BY FRIDAY MORNING AS
LOW PRESSURE OVER NORTHERN CANADA MOVES EAST.
&&
.PREV DISCUSSION... /ISSUED 320 AM CST THU NOV 17 2011/
SHORT TERM...
THE MAIN CHALLENGE WILL BE SNOW ACCUMULATION POTENTIAL IN THE
SOUTH ON SATURDAY. MODELS ARE IN VERY GOOD AGREEMENT WITH THIS
SYSTEM...AND THE GFS HAS BEEN VERY CONSISTENT OF LATE SO WILL UTILIZE.
FOR TODAY...SFC HIGH PRESSURE WILL QUICKLY MOVE OVER THE REGION
AND SLIDE EAST BY THIS EVENING. WITH TEMPS STARTING OUT COLD AND
SOME SNOW COVER IN THE NORTH...TEMPS WILL REMAIN BELOW NORMAL WITH
INCREASING MID/HIGH CLOUDS BY AFTERNOON. THERE WILL BE SOME BETTER
SATURATION IN THE FAR NW LATE THIS AFTERNOON SO WILL MENTION SOME
LOW POPS FOR LIGHT SNOW HERE.
FOR TONIGHT AND FRI...SFC LOW PRESSURE WILL TRACK ALONG OR JUST
NORTH OF THE INTERNATIONAL BORDER. STRONG MID LEVEL WAA AND
ISENTROPIC LIFT SHOULD MEAN THE THREAT FOR SOME LIGHT SNOW IN THE
FAR NORTH. THERE WILL BE A FAIRLY DEEP DRY LAYER IN PLACE
INITIALLY...SO MUCH OF THE LIFT WILL GO INTO SATURATING THE
COLUMN. WILL MAINTAIN SOME LOW POPS TONIGHT AND AGAIN FRIDAY
AFTERNOON IN THE NW WITH SOME WRAPAROUND SNOW SHOWERS POSSIBLE
NEAR THE COLD FRONT.
ON SATURDAY...A COLORADO LOW WILL QUICKLY EJECT INTO IOWA WITH A
POSITIVELY TILTED UPPER TROUGH. THERE WILL BE STRONG DEEP LAYERED
LIFT IN THE SOUTHERN 1/3 OF THE REGION PER Q VECTOR AND OMEGA
FIELDS. PWATS WILL BE AROUND 0.4 IN THE SOUTH...SUFFICIENT FOR 2-4
INCHES OF SNOW IN THE FAR SOUTH...TAPERING TO AROUND AN INCH OR
LESS NEAR FARGO. FURTHER NORTH...EXPECT DRY CONDITIONS AND
INCREASING NORTH WINDS WITH COLD AIR SPILLING INTO THE REGION.
TEMPS MAY EVEN FALL ON SATURDAY AFTERNOON WITH -15C AIR AT 850MB
MOVING INTO THE NORTH. THERE SHOULD BE SOME BLOWING SNOW IN THE
SOUTH WITH ABOUT 25-30KT TO MIX FROM AROUND 900MB...AND FAVORABLE
NORTHERLY VALLEY COMPONENT FOR CHANNEL LING WINDS. WILL MENTION IN
THE HWO WITH ADVISORY TYPE CONDITIONS POSSIBLE.
FOR SAT NIGHT...WITH CLEARING AFTER THE DEPARTING LOW...AND A
VERY COLD AIRMASS FOR THIS TIME OF YEAR...EXPECT LOWS NEAR OR
PERHAPS A FEW DEGREES BELOW ZERO BY SUNDAY MORNING IN THE NW.
LONG TERM...SUNDAY THROUGH WEDNESDAY NIGHT
GFS/ECMWF IN GOOD AGREEMENT THROUGH 00 UTC MONDAY...DIVERGING
SOMEWHAT THEREAFTER WITH STRENGTH AND TIMING OF INDIVIDUAL SHORT-
WAVES IN NEAR ZONAL FLOW ALOFT. SURFACE PATTERN WILL BE DOMINATED
BY A 1028 HPA HIGH AS IT MOVES SLOWLY ACROSS THE NORTHERN PLAINS AND
WITH LITTLE MOISTURE TO WORK WITH...EXPECT DRY CONDITIONS FOR THE
FIRST HALF OF NEXT WEEK. BIGGEST CHANGE TO SENSIBLE WEATHER WILL BE
A NICE WARMING TREND. TEMPERATURES IN THE 925 TO 850 HPA LAYER
INCREASE FROM NEAR -12 C SUNDAY MORNING TO +5 C ON WEDNESDAY. AS A
RESULT...EXPECT TEMPERATURES TO INCREASE A BIT EACH DAY...NEARING
40 DEGREES FOR HIGHS BY WEDNESDAY AFTERNOON.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
JR