AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
405 PM EST Sun Jan 1 2012
...Significant freeze events developing for Monday and Tuesday
nights...
.SYNOPSIS...
20Z water vapor and H4 RUC analysis shows an amplifying upper level
pattern across the CONUS this afternoon with longwave ridging across
the west and longwave troughing across the east. The main feature
for our forecast will be the longwave trough digging into the
eastern half of the nation, and its evolution over the next 24 to 36
hours. Shortwave energy dropping out of central Canada tonight into
Monday will act to further amplify/sharpen this trough and help
propel a significant arctic cold front through our forecast area.
At the surface,
A cold front currently crossing central/southern AL will enter our
far western zones during the next hour or so, and then quickly cross
the forecast area this evening. Just a few sprinkles seen on
regional radar along this front, however this activity is fighting
and losing the battle against a fairly dry atmospheric column seen
in this morning`s KTLH sounding profile. Temperatures are very
pleasant this afternoon with the forecast area situated within the
thermal ridge ahead of the surface trough. Most locations have
reached the middle to even upper 70s this afternoon...although
locations along the immediate coast of Apalachee Bay are holding in
the 60s with the flow off the relatively cooler shelf waters.
&&
.SHORT TERM (Tonight through Tuesday Night)...
Tonight,
The cold front will move south of the forecast area during the
overnight hours with skies clearing from NW to SE. Still just a
slight chance of a few isolated sprinkles along the frontal boundary
itself...however moisture is really lacking to support measurable
rainfall. The last of these sprinkles should be exiting south of
Cross City by midnight. Thereafter, a cooler and drier airmass will
be arriving on NW flow. Not expecting any freezing temperatures
overnight. Low temperatures by sunrise will range from the mid/upper
30s north of the I-10 corridor, to the mid 40s along the coast and
down across the SE FL Big Bend zones. For those far northern zones
that do reach the middle 30s, the gradient will remain tight enough,
and the dewpoint depressions will be large enough to likely prevent
any frost potential.
Monday/Monday Night,
A dry and cool day on tap with abundant sunshine. We will be saying
goodbye to the 70s as the new post-frontal airmass only supports
high temperatures in the middle/upper 50s. Aloft, the mid/upper
level trough will continue to amplify through the day. A strong
shortwave impulse shown by the ECMWF/GFS will round the base of this
trough Monday evening pushing an arctic cold front through the
region. This secondary front will deliver a significant surge of
cold air to the region (likely the coldest air most of us have seen
so far this winter). The arriving airmass is really quite impressive
for this part of the country. The GFS is showing 850mb temps over
the area down to between -6C to -10C by sunrise Tuesday, and the
ECMWF is between -8 to -13C. The true arctic nature of this airmass
can be seen in the profile below 850mb where temps of -6C to -9C are
progged down to 925 and below. Have issued a freeze watch for the
entire forecast area Monday night with the anticipation of low
temperatures by sunrise in the middle 20s inland and upper 20s to
around 30 at the coast. In addition, NW winds will drop wind chills
down into the upper teens. Confidence is increasing that wind chill
advisories will become necessary with future forecast packages.
Tuesday/Tuesday night,
Arctic airmass will be fully entrenched across the forecast area.
Will see significant recovery of the temps at 850mb, however both
ECMWF/GFS show much slower recovery below this level (which again
shows the arctic nature of the airmass). This trend eventually ends
up with an inverted low level profile by the afternoon hours. This
profile will significantly hinder diurnal mixing, and Tuesday is
going to end up a COLD day. With morning CAA and the low sun angle,
would not be surprised to see some of our northern zones stay below
freezing into the later morning hours. Even after midday, high
temps are likely to struggle into the lower 40s north, and middle
40s south. Have undercut the MAV numbers by several degrees as
statistical guidance often has difficulty with the true degree of
shallow arctic air. In fact, would also not be surprised if a few
spots up toward Albany and Tifton struggle to get out to the 30s.
Add in a NW wind and wind chill values are likely to remain in the
mid 30s to near 40 for much of the day. Surface high pressure will
then settle directly overhead Tuesday night. This high position
along with very dry low level air...a cold start to the evening and
long nights will set up excellent radiational cooling conditions. A
long duration, widespread freeze (and likely hard freeze) seems
probable. Once again have undercut the MAV numbers by a few degrees.
Temperatures inland are forecast to reach the upper teens/low 20s,
with middle to upper 20s for the immediate coast and for more
urbanized inland centers (like downtown Tallahassee).
&&
.LONG TERM (Wednesday through next Sunday)...
The large scale upper level pattern will continue to be anchored by
a negative anomaly over Alaska and a large positive anomaly across
the eastern Pacific, and will evolve toward a mean trough extending
from Hudson Bay to the southwest U.S., and another over the western
Atlantic. A very vigorous short wave will be moving rapidly eastward
away from the east coast Tuesday night and Wednesday, to be followed
by another much weaker one on Thursday. The upper level flow then
rapidly flattens out across the eastern U.S. by the end of the week,
in between the mean troughs over the southwest U.S. and the western
Atlantic. A weak short wave is forecast to move rapidly eastward
across the southeast U.S. on Saturday, bringing increased clouds and
possibly a few showers. Think the GFS overdoes the moisture
associated with this weak system, and prefer the drier Euro
solution. Temperatures will start out much below normal, with a hard
freeze likely for most areas Wednesday morning, as a cold dry
airmass remains centered over the southeast. After another frosty
morning Thursday, temperatures will begin to moderate steadily.
Heights will rise across the southeast in response to a strong short
wave dropping into the bottom of the mean trough over the southwest,
while the low level flow becomes more southerly as surface high
pressure weakens and moves into the western Atlantic. By the
weekend, temperatures will rise to above normal most areas. A weak
front is forecast to lie somewhere near or just north of the
Tri-State Area by Saturday. Prefer the EURO solution keeping the
front to the north of the area through the weekend, because the GFS
looks too fast and progressive with the next short wave , given the
expected mean trough position over the southwest.
&&
.MARINE...
Northwest and northerly winds will increase to advisory levels from
west to east this evening behind a passing cold front. These winds
will build the seas to cautionary levels over the nearshore legs,
and advisory levels offshore by Monday morning. Winds may briefly
drop below advisory levels for a period Monday afternoon, but will
increase once again Monday evening with the passage of a secondary
cold front. High end advisory conditions are expected Monday night
into early Tuesday, with a period of near gale force gusts becoming
more likely. Winds and seas will then gradually diminish Tuesday
afternoon and night as high pressure builds over the Northeast Gulf
of Mexico.
&&
.AVIATION (through 18Z Monday)...
A very sharp and dry cold front is moving rapidly southeast through
central Alabama. Southwest winds with gusts up to 20kts is occurring
ahead of the front. Behind the front winds are 15kts gusting to
20-26kts. CIGS have risen to VFR across Southeast Alabama and the
Florida Panhandle/Big Bend at KDHN, KECP and KTLH. Further east,
KABY and KVLD just now climbed out of IFR to VFR/MVFR levels.
Expect periods of CIGS around 5 to 6kft ahead of the cold front this
afternoon. This evening, the cold front will clear the clouds out
with gusty northwesterly winds that taper off overnight. Tomorrow
afternoon, strong gusty winds from the northwest will reappear by
late morning.
&&
.FIRE WEATHER...
A cold front will cross the forecast area this evening bringing a
cooler and drier airmass in its wake. Relative humidity values will
drop into the upper teens to middle 20s across the area during
Monday afternoon, along with gusty northwest winds. A secondary
arctic cold front will cross the area Monday evening delivering even
colder and drier air for Tuesday. Those with outdoor activities
planned for early Tuesday morning should anticipate widespread
sub-freezing temperatures, with wind chill values in the teens. Wind
chill values are likely to not climb out of the 30s Tuesday
afternoon over much of the area. Despite high temperatures only in
the lower to middle 40s on Tuesday, very dry low level air will
still allow relative humidity values to fall into the middle and
upper teens for much of the region. Another long duration and
widespread freeze or hard freeze is anticipated for Tuesday night
into Wednesday morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 42 57 26 46 19 / 20 0 0 0 0
Panama City 43 58 32 48 28 / 20 0 0 0 0
Dothan 39 56 27 45 23 / 10 0 0 0 0
Albany 38 56 25 43 20 / 20 0 0 0 0
Valdosta 40 56 25 45 19 / 20 0 0 0 0
Cross City 43 59 27 47 18 / 20 0 0 0 0
Apalachicola 43 58 30 48 24 / 20 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...Freeze Watch from late Monday night through Tuesday morning for
Coffee-Dale-Geneva-Henry-Houston.
Fire Weather Watch from Monday morning through Monday afternoon
for Coffee-Dale-Geneva-Henry-Houston.
GA...Freeze Watch from late Monday night through Tuesday morning for
Baker-Ben Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-
Decatur-Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes-
Miller-Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas-
Tift-Turner-Worth.
Fire Weather Watch Monday afternoon for Baker-Ben Hill-Berrien-
Brooks-Calhoun-Clay-Colquitt-Cook-Decatur-Dougherty-Early-
Grady-Irwin-Lanier-Lee-Lowndes-Miller-Mitchell-Quitman-
Randolph-Seminole-Terrell-Thomas-Tift-Turner-Worth.
FL...Freeze Watch from late Monday night through Tuesday morning for
Calhoun-Central Walton-Coastal Bay-Coastal Dixie-Coastal
Franklin-Coastal Gulf-Coastal Jefferson-Coastal Taylor-
Coastal Wakulla-Gadsden-Holmes-Inland Bay-Inland Dixie-
Inland Franklin-Inland Gulf-Inland Jefferson-Inland Taylor-
Inland Wakulla-Inland Walton-Jackson-Lafayette-Leon-Liberty-
Madison-South Walton-Washington.
Fire Weather Watch Monday afternoon for Calhoun-Central Walton-
Coastal Bay-Coastal Dixie-Coastal Franklin-Coastal Gulf-
Coastal Jefferson-Coastal Taylor-Coastal Wakulla-Gadsden-
Holmes-Inland Bay-Inland Dixie-Inland Franklin-Inland Gulf-
Inland Jefferson-Inland Taylor-Inland Wakulla-Inland Walton-
Jackson-Lafayette-Leon-Liberty-Madison-South Walton-
Washington.
GM...Small Craft Advisory from 7 PM this evening to 10 AM EST Tuesday
for Apalachee Bay-Coastal waters From Ochlockonee River to
Apalachicola FL out to 20 NM-Coastal waters from Suwannee
River to Keaton Beach FL out 20 NM-Coastal waters from
Apalachicola to Destin FL out 20 NM-Waters from Suwannee
River to Apalachicola FL from 20 to 60 NM-Waters from
Apalachicola to Destin FL from 20 to 60 NM.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
AVIATION/FIRE WEATHER...LANIER/MROCZKA
LONG TERM...DUVAL
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1220 AM EST TUE JAN 3 2012
.SYNOPSIS...
MUCH COLDER AND DRIER AIR WILL FILTER INTO THE REGION THROUGH
TUESDAY AS A STRONG CANADIAN HIGH PRESSURE CENTER DIVES SOUTHEAST
TOWARDS THE REGION. MODERATING TEMPERATURES EXPECTED LATE WEEK
INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
01Z UPDATE...UPPER LEVEL TROUGH AXIS IS SWINGING SOUTH ACROSS THE
FORECAST AREA THIS EVENING. THIS CAN BE SEEN WITHIN THE IR
SATELLITE AS SCATTERED INSTABILITY CLOUDS ARE NOW SHIFTING ACROSS
NORTHERN GA AND NORTHERN AND CENTRAL SC. UPDATED THE SKY GRIDS TO
REFLECT SOME CLOUDS THIS EVENING THEN CLEARING OUT AGAIN AFTER THE
TROUGH AXIS SWINGS THROUGH. USED RUC GUIDANCE THEN MASSAGED TOWARD
SATELLITE TRENDS. ALSO SLOWED DOWN FALLING TEMPS THIS EVENING
BASED ON CURRENT OBS BUT LOWS ARE UNCHANGED.
PREVIOUS DISCUSSION...
UPPER LEVEL TROUGH CONTINUES TO DIG SOUTH ACROSS THE EASTERN HALF
OF THE COUNTRY. MODELS SHOW AXIS WILL PASS OVER FORECAST AREA
OVERNIGHT AND BE ALONG THE COAST BY MORNING. AT THE SURFACE A
TIGHT PRESSURE GRADIENT EXISTS ACROSS EASTERN THIRD OF THE COUNTY
BETWEEN LOW PRESSURE OVER QUEBEC CANADA AND STRONG HIGH PRESSURE
ACROSS THE CENTRAL PLAINS. STRONG COLD ADVECTION OCCURRING OVER
THE FORECAST AREA THROUGH TONIGHT UNDER NORTHWEST WINDS.
PRECIPITABLE WATER VALUES ARE BELOW A QUARTER INCH AND THIS VERY
DRY AIR MASS WILL PREVENT ANY PRECIPITATION. STILL EXPECT LOWS TO
FALL INTO THE MID 20S. LAKE WIND ADVISORY REMAINS IN EFFECT.
LATEST OBS FROM AREA LAKES REPORTING GUSTS 15 TO 25 KTS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
UPPER RIDGE TO OUR WEST...WITH DEEPENING UPPER TROUGH OVER THE
EASTERN CONUS. NW FLOW ALOFT BRINGING IN COLD AND DRIER AIR.
PREFER LOWER GFS MOS DEWPOINTS FOR TUESDAY GIVEN LOW LEVEL
NORTHWEST WINDS/DOWNSLOPE FLOW. SUFFICIENT BOUNDARY LAYER
WIND...COLD AIR ADVECTION...AND ENHANCED MIXING OVER MUCH WARMER
LAKE WATER TEMPS WILL PROVIDE BREEZY CONDITIONS CONTINUING ON AREA
LAKES MONDAY NIGHT THROUGH TUESDAY. HAVE EXTENDED THE LAKE WIND
ADVISORY THROUGH TUESDAY AFTERNOON SINCE 12Z MODELS SUGGEST A
LITTLE MORE WIND. HIGH PRESSURE CENTER TO BUILD INTO OUR REGION
TUESDAY NIGHT/WED...WITH APPEARANCE OF GOOD RADIATIONAL COOLING
CONDITIONS...CLEAR SKIES AND LIGHT WINDS. SINCE VERY DRY AIR IS
EXPECTED TO BE IN PLACE...WILL LEAN A LITTLE LOWER THAN MODEL
GUIDANCE ON MIN TEMPS FOR TUE NIGHT...IN LINE WITH LOCAL RADIATION
SCHEME WITH HIGH CONFIDENCE OF WIDESPREAD MINIMUM TEMPERATURES IN
THE TEENS. WARM ADVECTION DEVELOPING WEDNESDAY BUT AIR MASS MAY
NOT MODIFY TOO QUICKLY SO PREFER COOLER ENSEMBLE MEAN GUIDANCE AND
TEMPERATURES REMAINING MAINLY IN THE 40S.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
DID NOT MAKE ANY REAL SIGNIFICANT CHANGES IN THE LONG TERM.
TEMPERATURES WILL CLIMB TO NEAR NORMAL BY THURSDAY...THEN ABOVE
NORMAL AS WE HEAD INTO THE WEEKEND. THURSDAY INTO FRIDAY WILL SEE
THE FLATTENING OF THE UPPER FLOW...AND WEAK RIDGING AHEAD OF THE NEXT
SYSTEM. COLD FRONT WILL APPROACH THE REGION OVER THE WEEKEND WITH
INCREASING MOISTURE. LOW PRESSURE MAY DEVELOP ALONG THE FRONT
ACROSS THE LOWER MISSISSIPPI VALLEY/GULF COAST SUNDAY/MONDAY AND TRACK
TOWARD THE CAROLINAS INCREASING THE THREAT FOR RAIN. THIS IS
SUPPORTED BY THE ECMWF AND TO A LESSER EXTENT...GFS.
AN APPROACHING FRONT WILL HELP TO INCREASE ATMOSPHERIC MOISTURE BY
THE WEEKEND. CONTINUED WITH INCREASED POPS AND WARM TEMPS DUE TO
STRONG LOW LEVEL FLOW OVER THE WEEKEND AHEAD OF APPROACHING COLD
FRONT.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE 24 HOUR TAF PERIOD. BREEZY
CONDITIONS WILL CONTINUE OVERNIGHT AND TUESDAY. WINDS WILL
DIMINISH TUESDAY NIGHT AS A HIGH PRESSURE CENTER MOVES IN. AN UPPER
TROUGH CURRENTLY PUSHING THROUGH THE AREA WILL PROVIDE SOME MID
LEVEL CLOUDINESS EARLY IN THE TAF PERIOD...BUT NO SIGNIFICANT
PRECIPITATION EXPECTED DUE TO VERY DRY LOW LEVEL AIR. NO FOG DUE TO
DRY AIR.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.FIRE WEATHER...
MUCH COLDER AND DRIER AIR WILL CONTINUE TO FILTER INTO THE
REGION OVERNIGHT UNDER WEST TO NORTHWEST WINDS. RELATIVE HUMIDITY
VALUES FROM THIS AFTERNOON DROPPED TO AROUND 20 PERCENT. RH WILL
BE EVEN LOWER TUESDAY AFTERNOON...AROUND 15 PERCENT. WINDY CONDITIONS
ARE EXPECTED TONIGHT THROUGH TUESDAY. FUEL MOISTURE IS MARGINAL THOUGH
AND THE COLD TEMPERATURES ARE A LIMITING FACTOR FOR WILDFIRE
DEVELOPMENT. SPC FIRE GUIDANCE SUGGESTS GREATER THREAT REMAINS
SOUTH OF THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...LAKE WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR SCZ015-016-
018-020>022-025>031-035>038-041.
GA...LAKE WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR GAZ040-
063>065-077.
&&
$$
AVIATION...DCM
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
829 PM EST MON JAN 2 2012
.SYNOPSIS...
MUCH COLDER AND DRIER AIR WILL FILTER INTO THE REGION THROUGH
TUESDAY AS A STRONG CANADIAN HIGH PRESSURE CENTER DIVES SOUTHEAST TOWARDS
THE REGION. MODERATING TEMPERATURES EXPECTED LATE WEEK INTO THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
01Z UPDATE...UPPER LEVEL TROUGH AXIS IS SWINGING SOUTH ACROSS THE
FORECAST AREA THIS EVENING. THIS CAN BE SEEN WITHIN THE IR
SATELLITE AS SCATTERED INSTABILITY CLOUDS ARE NOW SHIFTING ACROSS
NORTHERN GA AND NORTHERN AND CENTRAL SC. UPDATED THE SKY GRIDS TO
REFLECT SOME CLOUDS THIS EVENING THEN CLEARING OUT AGAIN AFTER THE
TROUGH AXIS SWINGS THROUGH. USED RUC GUIDANCE THEN MASSAGED TOWARD
SATELLITE TRENDS. ALSO SLOWED DOWN FALLING TEMPS THIS EVENING
BASED ON CURRENT OBS BUT LOWS ARE UNCHANGED.
PREVIOUS DISCUSSION...
UPPER LEVEL TROUGH CONTINUES TO DIG SOUTH ACROSS THE EASTERN HALF
OF THE COUNTRY. MODELS SHOW AXIS WILL PASS OVER FORECAST AREA
OVERNIGHT AND BE ALONG THE COAST BY MORNING. AT THE SURFACE A
TIGHT PRESSURE GRADIENT EXISTS ACROSS EASTERN THIRD OF THE COUNTY
BETWEEN LOW PRESSURE OVER QUEBEC CANADA AND STRONG HIGH PRESSURE
ACROSS THE CENTRAL PLAINS. STRONG COLD ADVECTION OCCURRING OVER
THE FORECAST AREA THROUGH TONIGHT UNDER NORTHWEST WINDS.
PRECIPITABLE WATER VALUES ARE BELOW A QUARTER INCH AND THIS VERY
DRY AIR MASS WILL PREVENT ANY PRECIPITATION. STILL EXPECT LOWS TO
FALL INTO THE MID 20S. LAKE WIND ADVISORY REMAINS IN EFFECT.
LATEST OBS FROM AREA LAKES REPORTING GUSTS 15 TO 25 KTS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
UPPER RIDGE TO OUR WEST...WITH DEEPENING UPPER TROUGH OVER THE
EASTERN CONUS. NW FLOW ALOFT BRINGING IN COLD AND DRIER AIR.
PREFER LOWER GFS MOS DEWPOINTS FOR TUESDAY GIVEN LOW LEVEL
NORTHWEST WINDS/DOWNSLOPE FLOW. SUFFICIENT BOUNDARY LAYER
WIND...COLD AIR ADVECTION...AND ENHANCED MIXING OVER MUCH WARMER
LAKE WATER TEMPS WILL PROVIDE BREEZY CONDITIONS CONTINUING ON AREA
LAKES MONDAY NIGHT THROUGH TUESDAY. HAVE EXTENDED THE LAKE WIND
ADVISORY THROUGH TUESDAY AFTERNOON SINCE 12Z MODELS SUGGEST A
LITTLE MORE WIND. HIGH PRESSURE CENTER TO BUILD INTO OUR REGION
TUESDAY NIGHT/WED...WITH APPEARANCE OF GOOD RADIATIONAL COOLING
CONDITIONS...CLEAR SKIES AND LIGHT WINDS. SINCE VERY DRY AIR IS
EXPECTED TO BE IN PLACE...WILL LEAN A LITTLE LOWER THAN MODEL
GUIDANCE ON MIN TEMPS FOR TUE NIGHT...IN LINE WITH LOCAL RADIATION
SCHEME WITH HIGH CONFIDENCE OF WIDESPREAD MINIMUM TEMPERATURES IN
THE TEENS. WARM ADVECTION DEVELOPING WEDNESDAY BUT AIR MASS MAY
NOT MODIFY TOO QUICKLY SO PREFER COOLER ENSEMBLE MEAN GUIDANCE AND
TEMPERATURES REMAINING MAINLY IN THE 40S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
DID NOT MAKE ANY REAL SIGNIFICANT CHANGES IN THE LONG TERM.
TEMPERATURES WILL CLIMB TO NEAR NORMAL BY THURSDAY...THEN ABOVE
NORMAL AS WE HEAD INTO THE WEEKEND. THURSDAY INTO FRIDAY WILL SEE
THE FLATTENING OF THE UPPER FLOW...AND WEAK RIDGING AHEAD OF THE NEXT
SYSTEM. COLD FRONT WILL APPROACH THE REGION OVER THE WEEKEND WITH
INCREASING MOISTURE. LOW PRESSURE MAY DEVELOP ALONG THE FRONT
ACROSS THE LOWER MISSISSIPPI VALLEY/GULF COAST SUNDAY/MONDAY AND TRACK
TOWARD THE CAROLINAS INCREASING THE THREAT FOR RAIN. THIS IS
SUPPORTED BY THE ECMWF AND TO A LESSER EXTENT...GFS.
AN APPROACHING FRONT WILL HELP TO INCREASE ATMOSPHERIC MOISTURE BY
THE WEEKEND. CONTINUED WITH INCREASED POPS AND WARM TEMPS DUE TO
STRONG LOW LEVEL FLOW OVER THE WEEKEND AHEAD OF APPROACHING COLD
FRONT.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
EXPECT VFR CONDITIONS THROUGH THE TAF PERIOD. WINDS WILL BE THE
MAIN AVIATION CONCERN. WINDS WILL BE GUSTY AT TIMES BECAUSE OF
STRONG COLD ADVECTION TONIGHT AND INCREASED MIXING FROM HEATING AFTER
14Z. MODEL TIME-HEIGHT DISPLAYS SUPPORT GUSTS OF 20 TO 25 KNOTS.
THE DRY AIR MASS AND WIND SHOULD PREVENT FOG.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.FIRE WEATHER...
MUCH COLDER AND DRIER AIR WILL CONTINUE TO FILTER INTO THE
REGION OVERNIGHT UNDER WEST TO NORTHWEST WINDS. RELATIVE HUMIDITY
VALUES FROM THIS AFTERNOON DROPPED TO AROUND 20 PERCENT. RH WILL
BE EVEN LOWER TUESDAY AFTERNOON...AROUND 15 PERCENT. WINDY CONDITIONS
ARE EXPECTED TONIGHT THROUGH TUESDAY. FUEL MOISTURE IS MARGINAL THOUGH
AND THE COLD TEMPERATURES ARE A LIMITING FACTOR FOR WILDFIRE
DEVELOPMENT. SPC FIRE GUIDANCE SUGGESTS GREATER THREAT REMAINS
SOUTH OF THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...LAKE WIND ADVISORY UNTIL 6 PM EST TUESDAY FOR SCZ015-016-018-
020>022-025>031-035>038-041.
GA...LAKE WIND ADVISORY UNTIL 6 PM EST TUESDAY FOR GAZ040-063>065-
077.
&&
$$
NEAR TERM...SMITH
AVIATION...73
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1124 AM CST SUN JAN 1 2012
.DISCUSSION...
ISSUED 1020 AM CST SUN JAN 1 2012
COLD FRONT IS APPROACHING THE INDIANA/OHIO BORDER LATE THIS
MORNING. TRAILING STRATOCUMULUS DECK IS QUICKLY PUSHING THROUGH
THE CWA...AND IS CURRENTLY MAINLY CLEAR WEST OF I-57. REMAINING
CLOUD COVER FROM THIS DECK WILL MOVE OUT SHORTLY. HOWEVER...SOME
MORE DIURNAL CUMULUS IS QUICKLY DROPPING SOUTH OUT OF
WISCONSIN/NORTHEAST IOWA. AREAS NORTH OF I-74 MOST LIKELY TO BE
IMPACTED BY THOSE CLOUDS BY EARLY AFTERNOON. SOME SNOW SHOWERS
CURRENTLY APPEARING ON RADAR MOSAICS ACROSS WESTERN WISCONSIN.
LATEST HRRR APPEARS TO HAVE A GOOD HANDLE ON IT...AND TRACKS THESE
JUST TO OUR NORTHEAST THIS AFTERNOON...SO WILL NOT ADD ANY TO OUR
GRIDS AT THIS TIME. HOWEVER...CANNOT RULE OUT A STRAY FLURRY.
HAVE KEPT WIND ADVISORY GOING...ALTHOUGH WE ARE SEEING A FEW LULLS
IN SOME AREAS AT THE MOMENT. BUFKIT MOMENTUM TRANSFER OFF THE
LATEST NAM STILL SHOWING AROUND 45 KNOTS AROUND 900 MB...WHICH
SHOULD BE MIXED DOWN WITH THE ABUNDANT SUNSHINE. WITH THIS
SUNSHINE...HAVE UPDATED HOURLY TEMPERATURE TRENDS TO KEEP THINGS
STEADY OR RISING A COUPLE DEGREES THROUGH MIDDAY...BEFORE FALLING
THIS AFTERNOON AS 850 MB TEMPERATURES DROP TO NEAR -10C ACROSS THE
NORTHERN CWA.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 1123 AM CST SUN JAN 1 2012
LINGERING MVFR CEILINGS AT KCMI HAVE MOVED EASTWARD. WILL SEE A
COUPLE MORE HOURS OF CLEAR SKIES AT MOST OF THE TAF SITES...BEFORE
AN AREA OF CEILINGS AROUND 4000 FEET DROPS SOUTHWARD. AWIPS
TIME-OF-ARRIVAL TOOL HAS THIS ARRIVING FROM KPIA-KCMI IN THE 21Z
TIME FRAME. CYCLONIC CIRCULATION OVER THE GREAT LAKES WILL KEEP
PERIODS OF VFR CEILINGS LINGERING INTO MONDAY IN THESE
AREAS...WITH MAINLY SCATTERED CLOUDS FURTHER SOUTH. WIND-WISE...
STILL WILL SEE SOME 30-40 KNOT WIND GUSTS FOR A FEW MORE
HOURS...BEFORE SOME DIMINISHING TAKES PLACE LATER THIS AFTERNOON
AND OVERNIGHT. HOWEVER...WE WILL LIKELY SEE GUSTS AGAIN OVER 30
KNOTS ON MONDAY MORNING.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 325 AM CST SUN JAN 1 2012
BIGGEST FORECAST CONCERN IS HOW STRONG WINDS GET TODAY AND HOW
LONG TO HAVE WIND ADVISORY. STRONG WINDS TODAY DUE TO 1000 MB LOW
PRESSURE OVER FAR NW IL DEEPENS AS IT MOVES NE ACROSS THE CENTRAL
GREAT LAKES REGION AND INTO FAR EASTERN ONTARIO BY 00Z/6 PM. MUCH
COLDER AIR TO USHER INTO IL ON STRONG WNW BEHIND A COLD FRONT
TODAY. 00Z MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND USED A
BLEND. QUIET WEATHER EXPECTED FROM TONIGHT THROUGH FRIDAY AS COLD
TEMPERATURES EARLY THIS WEEK MODERATE BACK ABOVE NORMAL DURING THE
SECOND HALF OF THE WORK WEEK.
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
09Z/3 AM SURFACE MAP SHOWS 1000 MB LOW PRESSURE OVER FAR NW IL
WITH ITS COLD FRONT THROUGH WESTERN IL INTO SE MO AND EASTERN AR.
SSW WINDS AHEAD OF COLD FRONT TURN WNW BEHIND THE FRONT. WIND
GUSTS AHEAD OF COLD FRONT GENERALLY 20 TO 32 MPH AND INCREASE TO
25 TO 37 MPH BEHIND THE COLD FRONT. NARROW BAND OF POST FRONTAL RAIN
SHOWERS NEAR THE IA/IL MS RIVER BORDER AND A FEW MORE RAIN SHOWERS
BETWEEN ST LOUIS AND JACKSONVILLE MOVING EAST. MILD TEMPS IN THE
40S OVER CENTRAL AND SE IL EARLY THIS MORNING. DEWPOINTS WERE IN
THE MID TO UPPER 30S. WILL CARRY A 20-40% CHANCE OF RAIN SHOWERS
OVER CENTRAL IL THIS MORNING AND COULD MIX WITH LIGHT SNOW BUT NO
ACCUMULATIONS. KEEPING IN DRY IN FAR SE IL BY LAWRENCEVILLE TODAY.
MODELS SWEEP COLD FRONT QUICKLY EAST TOWARD THE IL/IN BORDER BY
12Z/6 AM THIS MORNING WITH 1000 MB LOW PRESSURE OVER NW IL
DEEPENING NE TO 995 MB OVER FAR NW LOWER MI BY 18Z/NOON AND TO 990
MB OVER FAR EASTERN ONTARIO BY 00Z/6 PM. MEANWHILE 1037 MB HIGH
PRESSURE OVER THE ROCKIES TO STRENGTHEN TO 1042 MB INTO THE HIGH
PLAINS BY EARLY EVENING. THIS TO GENERATE A VERY TIGHT PRESSURE
GRADIENT OVER IL BEHIND THE COLD FRONT TODAY WITH MIXING UP TO
5-6K FT AS SKIES BECOME PARTLY TO MOSTLY SUNNY FOR A TIME AND WNW
WINDS OF 20 TO 30 MPH AND GUSTS OF 40 TO 50 MPH FROM LATE MORNING
INTO THE AFTERNOON. EARLY MORNING HIGHS TO RANGE FROM THE UPPER
30S AND LOWER 40S...WITH MID 40S ALONG THE WABASH RIVER. TEMPS
COOL INTO THE LOW TO MID 30S BY SUPPER TIME TODAY.
WILL CONTINUE THE WIND ADVISORY TODAY AND THIS EVENING ACROSS
CENTRAL AND SE IL WITH STRONGEST WINDS EXPECTED LATE MORNING AND
AFTERNOON. INCREASED WIND SPEEDS MONDAY WITH PRESSURE GRADIENT
REMAINING QUITE STRONG WITH WINDS GUSTS OF 30 TO 40 MPH EXPECTED.
ALSO INCREASE CLOUD COVER ESPECIALLY OVER EASTERN IL WITH STRONG
UPPER LEVEL TROF DIGGING OVER THE EASTERN STATES LATE TONIGHT AND
MONDAY AND THEN SHIFTING EASTWARD MONDAY NIGHT AS SURFACE RIDGE
SETTLES EAST INTO THE MS RIVER VALLEY BY DAWN TUE. LOW CLOUDS AND
WINDS TO DECREASE FROM WEST TO EAST DURING MONDAY NIGHT. LOWS
TONIGHT MOSTLY IN THE LOWER 20S WITH SUBFREEZING HIGHS MON OF 25
TO 30F. LOWS MONDAY NIGHT IN THE LOW TO MID TEENS WITH SUBFREEZING
HIGHS AGAIN ON TUE IN THE UPPER 20S TO AROUND 30F. HIGH PRESSURE
RIDGE SHIFTING EAST OF IL BY TUE EVENING TO START MODERATING TEMPS
WITH SOUTHERLY FLOW SETTING UP FOR A FEW DAYS. A NORTHERN STREAM
SHORT WAVE TO MOVE ACROSS NORTHERN IL OVERNIGHT TUE NIGHT KEEPING
ITS LIGHT PRECIPITATION AND MORE CLOUDS NORTH IN THE GREAT LAKES
REGION. MOSTLY SUNNY SKIES EXPECTED TUE AND WED WITH HIGHS
MODERATING ABOUT 10 DEGREES TO UPPER 30S AND LOWER 40S WED.
LONG TERM...THURSDAY THROUGH SATURDAY NIGHT
DRY CONDITIONS GENERALLY EXPECTED LATE THIS WEEK WITH ABOVE NORMAL
TEMPERATURES WITH MILDEST READINGS ON FRIDAY WITH LOWER 50S. THIS
DUE TO UPPER LEVEL RIDGING INTO THE MS VALLEY AND WEATHER
DISTURBANCES PASSING NORTH OF IL ALONG THE US/CANADIAN BORDER AND
SOUTH OF IL TOO IN A SPLIT UPPER LEVEL FLOW.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR ILZ027>031-036>038-
040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1021 AM CST SUN JAN 1 2012
.DISCUSSION...
ISSUED 1020 AM CST SUN JAN 1 2012
COLD FRONT IS APPROACHING THE INDIANA/OHIO BORDER LATE THIS
MORNING. TRAILING STRATOCUMULUS DECK IS QUICKLY PUSHING THROUGH
THE CWA...AND IS CURRENTLY MAINLY CLEAR WEST OF I-57. REMAINING
CLOUD COVER FROM THIS DECK WILL MOVE OUT SHORTLY. HOWEVER...SOME
MORE DIURNAL CUMULUS IS QUICKLY DROPPING SOUTH OUT OF
WISCONSIN/NORTHEAST IOWA. AREAS NORTH OF I-74 MOST LIKELY TO BE
IMPACTED BY THOSE CLOUDS BY EARLY AFTERNOON. SOME SNOW SHOWERS
CURRENTLY APPEARING ON RADAR MOSAICS ACROSS WESTERN WISCONSIN.
LATEST HRRR APPEARS TO HAVE A GOOD HANDLE ON IT...AND TRACKS THESE
JUST TO OUR NORTHEAST THIS AFTERNOON...SO WILL NOT ADD ANY TO OUR
GRIDS AT THIS TIME. HOWEVER...CANNOT RULE OUT A STRAY FLURRY.
HAVE KEPT WIND ADVISORY GOING...ALTHOUGH WE ARE SEEING A FEW LULLS
IN SOME AREAS AT THE MOMENT. BUFKIT MOMENTUM TRANSFER OFF THE
LATEST NAM STILL SHOWING AROUND 45 KNOTS AROUND 900 MB...WHICH
SHOULD BE MIXED DOWN WITH THE ABUNDANT SUNSHINE. WITH THIS
SUNSHINE...HAVE UPDATED HOURLY TEMPERATURE TRENDS TO KEEP THINGS
STEADY OR RISING A COUPLE DEGREES THROUGH MIDDAY...BEFORE FALLING
THIS AFTERNOON AS 850 MB TEMPERATURES DROP TO NEAR -10C ACROSS THE
NORTHERN CWA.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 520 AM CST SUN JAN 1 2012
STRONG WINDS THE MAIN CONCERN THIS FORECAST PERIOD WITH A
SECONDARY CONCERN BEING THE DURATION OF THE MVFR AND LOCAL
IFR CIGS THIS MORNING JUST BEHIND THE COLD FRONT. STRONG
LOW PRESSURE OVER SOUTHEAST WISCONSIN WILL SHIFT WELL OFF
TO OUR EAST TODAY BUT THE TIGHT PRESSURE GRADIENT ASSOCIATED
WITH THE STORM SYSTEM WILL PRODUCE THE GUSTY WEST TO NORTHWEST
WINDS INTO TONIGHT. WIND GUSTS AS HIGH AS 45 KTS WILL BE
POSSIBLE AT TIMES TODAY...WITH ONLY A GRADUAL DECREASE IN
SPEEDS EXPECTED TONIGHT. BASED ON CURRENT TRENDS IN SATELLITE
IT APPEARS THE INITIAL BAND OF MVFR/IFR CIGS WILL PUSH INTO
EAST CENTRAL IL BY 16Z...WITH VFR CONDITIONS INTO EARLY THIS
AFTN...FOLLOWED BY ANOTHER BAND OF LOW VFR CIGS FOR THIS
AFTN AND THIS EVENING AS THE STRONGER PUSH OF COLD AIR SHIFTS
SOUTHEAST INTO OUR AREA. A NARROW BAND OF RAIN WITH A FEW
REPORTS OF SLEET WEST OF PIA WILL TRACK QUICKLY ACRS THE
TAF SITES THIS MORNING. HAVE EVEN HAD SOME LIGHTNING WITH
THE BAND OF SHOWERS PUSHING EAST OF I-57. MOST OF THE PRECIP
SHOULD PUSH EAST OF THE AREA BY 15Z.
SMITH
&&
.PREV DISCUSSION...
ISSUED 325 AM CST SUN JAN 1 2012
BIGGEST FORECAST CONCERN IS HOW STRONG WINDS GET TODAY AND HOW
LONG TO HAVE WIND ADVISORY. STRONG WINDS TODAY DUE TO 1000 MB LOW
PRESSURE OVER FAR NW IL DEEPENS AS IT MOVES NE ACROSS THE CENTRAL
GREAT LAKES REGION AND INTO FAR EASTERN ONTARIO BY 00Z/6 PM. MUCH
COLDER AIR TO USHER INTO IL ON STRONG WNW BEHIND A COLD FRONT
TODAY. 00Z MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND USED A
BLEND. QUIET WEATHER EXPECTED FROM TONIGHT THROUGH FRIDAY AS COLD
TEMPERATURES EARLY THIS WEEK MODERATE BACK ABOVE NORMAL DURING THE
SECOND HALF OF THE WORK WEEK.
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
09Z/3 AM SURFACE MAP SHOWS 1000 MB LOW PRESSURE OVER FAR NW IL
WITH ITS COLD FRONT THROUGH WESTERN IL INTO SE MO AND EASTERN AR.
SSW WINDS AHEAD OF COLD FRONT TURN WNW BEHIND THE FRONT. WIND
GUSTS AHEAD OF COLD FRONT GENERALLY 20 TO 32 MPH AND INCREASE TO
25 TO 37 MPH BEHIND THE COLD FRONT. NARROW BAND OF POST FRONTAL RAIN
SHOWERS NEAR THE IA/IL MS RIVER BORDER AND A FEW MORE RAIN SHOWERS
BETWEEN ST LOUIS AND JACKSONVILLE MOVING EAST. MILD TEMPS IN THE
40S OVER CENTRAL AND SE IL EARLY THIS MORNING. DEWPOINTS WERE IN
THE MID TO UPPER 30S. WILL CARRY A 20-40% CHANCE OF RAIN SHOWERS
OVER CENTRAL IL THIS MORNING AND COULD MIX WITH LIGHT SNOW BUT NO
ACCUMULATIONS. KEEPING IN DRY IN FAR SE IL BY LAWERNCEVILLE TODAY.
MODELS SWEEP COLD FRONT QUICKLY EAST TOWARD THE IL/IN BORDER BY
12Z/6 AM THIS MORNING WITH 1000 MB LOW PRESSURE OVER NW IL
DEEPENING NE TO 995 MB OVER FAR NW LOWER MI BY 18Z/NOON AND TO 990
MB OVER FAR EASTERN ONTARIO BY 00Z/6 PM. MEANWHILE 1037 MB HIGH
PRESSURE OVER THE ROCKIES TO STRENGHTHEN TO 1042 MB INTO THE HIGH
PLAINS BY EARLY EVENING. THIS TO GENERATE A VERY TIGHT PRESSURE
GRADIENT OVER IL BEHIND THE COLD FRONT TODAY WITH MIXING UP TO
5-6K FT AS SKIES BECOME PARTLY TO MOSTLY SUNNY FOR A TIME AND WNW
WINDS OF 20 TO 30 MPH AND GUSTS OF 40 TO 50 MPH FROM LATE MORNING
INTO THE AFTERNOON. EARLY MORNING HIGHS TO RANGE FROM THE UPPER
30S AND LOWER 40S...WITH MID 40S ALONG THE WABASH RIVER. TEMPS
COOL INTO THE LOW TO MID 30S BY SUPPER TIME TODAY.
WILL CONTINUE THE WIND ADVISORY TODAY AND THIS EVENING ACROSS
CENTRAL AND SE IL WITH STRONGEST WINDS EXPECTED LATE MORNING AND
AFTERNOON. INCREASED WIND SPEEDS MONDAY WITH PRESSURE GRADIENT
REMAINING QUITE STRONG WITH WINDS GUSTS OF 30 TO 40 MPH EXPECTED.
ALSO INCREASE CLOUD COVER ESPECIALLY OVER EASTERN IL WITH STRONG
UPPER LEVEL TROF DIGGING OVER THE EASTERN STATES LATE TONIGHT AND
MONDAY AND THEN SHIFTING EASTWARD MONDAY NIGHT AS SURFACE RIDGE
SETTLES EAST INTO THE MS RIVER VALLEY BY DAWN TUE. LOW CLOUDS AND
WINDS TO DECREASE FROM WEST TO EAST DURING MONDAY NIGHT. LOWS
TONIGHT MOSTLY IN THE LOWER 20S WITH SUBFREEZING HIGHS MON OF 25
TO 30F. LOWS MONDAY NIGHT IN THE LOW TO MID TEENS WITH SUBFREEZING
HIGHS AGAIN ON TUE IN THE UPPER 20S TO AROUND 30F. HIGH PRESSURE
RIDGE SHIFTING EAST OF IL BY TUE EVENING TO START MODERATING TEMPS
WITH SOUTHERLY FLOW SETTING UP FOR A FEW DAYS. A NORTHERN STREAM
SHORT WAVE TO MOVE ACROSS NORTHERN IL OVERNIGHT TUE NIGHT KEEPING
ITS LIGHT PRECIPITATION AND MORE CLOUDS NORTH IN THE GREAT LAKES
REGION. MOSTLY SUNNY SKIES EXPECTED TUE AND WED WITH HIGHS
MODERATING ABOUT 10 DEGREES TO UPPER 30S AND LOWER 40S WED.
LONG TERM...THURSDAY THROUGH SATURDAY NIGHT
DRY CONDITIONS GENERALLY EXPECTED LATE THIS WEEK WITH ABOVE NORMAL
TEMPERATURES WITH MILDEST READINGS ON FRIDAY WITH LOWER 50S. THIS
DUE TO UPPER LEVEL RIDGING INTO THE MS VALLEY AND WEATHER
DISTURBANCES PASSING NORTH OF IL ALONG THE US/CANADIAN BORDER AND
SOUTH OF IL TOO IN A SPLIT UPPER LEVEL FLOW.
HUETTL
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR ILZ027>031-036>038-
040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
348 AM EST TUE JAN 3 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
SNOW SHOWERS WILL END OVER NORTHEASTERN PORTIONS OF CENTRAL INDIANA
BY MIDDAY AS HIGH PRESSURE BUILDS INTO THE REGION. TEMPERATURES WILL
REMAIN COLD TODAY WITH MANY LOCATIONS REMAINING IN THE 20S. UPPER
LEVEL RIDGING WILL EXPAND INTO THE OHIO VALLEY DURING THE SECOND
HALF OF THE WEEK...BRINGING WARMER TEMPERATURES AND DRY CONDITIONS
THROUGH THE UPCOMING WEEKEND.
&&
.NEAR TERM /TODAY/...
SKIES HAVE BEEN CLEAR FOR MUCH OF THE OVERNIGHT ACROSS ALL BUT
NORTHEAST SECTIONS OF THE FORECAST AREA WHERE THE VEERING LOW LEVEL
FLOW HAS ENABLED EDGES OF THE LAKE EFFECT BANDS TO REACH DOWN INTO
AREAS EAST OF KOKOMO AND ANDERSON. WINDS HAVE STEADILY WEAKENED OVER
THE LAST SEVERAL HOURS WITH MAX GUSTS GENERALLY NO HIGHER THAN
20MPH. TEMPERATURES AT 08Z WERE IN THE TEENS AND LOWER 20S.
FOCUS REMAINS ON THE CONTINUATION OF SNOW SHOWERS AND FLURRIES OVER
NORTHEAST COUNTIES BEFORE FAVORABLE LOW LEVEL FLOW COLLAPSES BY
MIDDAY. HAVE RELIED ON HRRR AND RUC INITIALLY THIS MORNING WITH
RESPECT TO LOCATION OF SNOW BANDS.
RADAR MOSAIC OVER THE REGION HAS SHOWN A SLOW DECLINE IN SNOW BAND
INTENSITY ACROSS NORTHERN INDIANA AS BOUNDARY LAYER WINDS WEAKEN.
THIS TREND SHOULD CONTINUE THROUGH THE NEXT SEVERAL HOURS AS WIND
SPEEDS BETWEEN 925MB AND 800MB DROP TO 15-20MPH. THIS WILL MAKE IT
INCREASING MORE DIFFICULT FOR THE STEADIER BANDS TO MAKE IT INTO
NORTHEAST COUNTIES AND A NOTED DECREASE IN SNOWFALL INTENSITY AND
COVERAGE SHOULD OCCUR OVER THE NEXT 3-5 HOURS. AS THE MORNING
PROGRESSES...ARRIVAL OF THE HIGH PRESSURE RIDGE WILL FURTHER WEAKEN
LOW LEVEL FLOW WITH WINDS BACKING TO A MORE W/NW DIRECTION BY EARLY
AFTERNOON. WILL CARRY SCATTERED SNOW SHOWERS AND FLURRIES EAST OF A
KOKOMO-ANDERSON-NEW CASTLE LINE THROUGH MIDDAY WITH ANY LEFTOVER
FLURRIES SHIFTING NORTH OF THE FORECAST AREA THEREAFTER AS WINDS
BACK. ISOLATED ACCUMULATIONS OF A COUPLE TENTHS OF AN INCH CANNOT BE
RULED OUT EARLY THIS MORNING...ESPECIALLY OVER DELAWARE AND RANDOLPH
COUNTIES. WILL FRESHEN SPS TO HIGHLIGHT.
DRY WEATHER IS EXPECTED OVER THE REMAINDER OF THE FORECAST AREA WITH
THE EXPANSION OF SAID HIGH PRESSURE RIDGE INTO THE REGION. RUC/NAM
BOTH SUGGESTIVE OF SOME DIURNAL CU DEVELOPMENT THIS MORNING WITH LOW
LEVEL THERMAL TROUGH ALIGNED JUST EAST OF THE REGION. HOWEVER AS
WINDS BACK AND DRIER AIR ADVECTS INTO THE REGION FROM THE WEST
SHOULD SEE SKIES BECOME MAINLY SUNNY FOR THE AFTERNOON. EXCEPTION
WILL BE OVER NORTHEAST COUNTIES WHERE COLDEST BOUNDARY LAYER
CONDITIONS MAY ENABLE CLOUDS TO LINGER THROUGH MID AFTERNOON BEFORE
DIMINISHING.
TEMPS...DESPITE THE POTENTIAL FOR PLENTY OF SUNSHINE TODAY...WARM
ADVECTION DOES NOT REALLY COMMENCES UNTIL LATE DAY. COMBINED WITH
POOR MIXING LEVELS TO ONLY ABOUT 2KFT THIS AFTERNOON...MANY
LOCATIONS WILL BE HARD PRESSED TO CLIMB OUT OF THE 20S. TRENDED MUCH
CLOSER TO COOLER MAVMOS GUIDANCE.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON TEMPS AND CLOUDS IN AN OTHERWISE BENIGN
PERIOD. MODEL GUIDANCE IS SIMILAR ON MAIN FEATURES THROUGH THE SHORT
TERM AND HAVE TAKEN A BLEND.
SURFACE HIGH PRESSURE THROUGH THE PERIOD AND THE EXPANSION OF A
BROAD UPPER RIDGE BY THURSDAY INTO THE OHIO VALLEY WILL BOTH BE KEY
FEATURES IN KEEPING WEATHER DRY OVER CENTRAL INDIANA WITH A
TEMPERATURE RECOVERY BACK TO ABOVE NORMAL LEVELS BY THE END OF THE
PERIOD. TWO WEAK UPPER LEVEL DISTURBANCES WILL PASS NORTH OF THE
REGION EARLY WEDNESDAY MORNING AND AGAIN WEDNESDAY NIGHT. BOTH OF
THESE FEATURES WILL BRING A PERIOD OF INCREASED MID AND HIGH LEVEL
CLOUDINESS OVER MAINLY NORTHERN SECTIONS OF THE FORECAST AREA.
POTENTIAL FOR SOME STRATOCU DEVELOPMENT WEDNESDAY AS QUICK SHOT OF
COLD ADVECTION FOLLOWS IN WAKE OF THE INITIAL SHORTWAVE PASSAGE
ALOFT. THE EXPANSION OF THE UPPER RIDGE INTO THE REGION BY THURSDAY
WILL ENABLE A MORE SUBSTANTIAL PUSH OF MILDER AIR INTO CENTRAL
INDIANA ALONG WITH INCREASING SUNSHINE BY THURSDAY AFTERNOON. DRY
WEATHER WITH MOSTLY CLEAR SKIES WILL CONTINUE THURSDAY NIGHT AS MID
LEVEL HEIGHTS FURTHER RISE OVER THE REGION.
TEMPS...LOWS TONIGHT WILL BE REACHED DURING THE EVENING AS WARM
ADVECTION AHEAD OF THE INITIAL SHORTWAVE ENABLES STEADY OR SLOWLY
RISING TEMPS THROUGH THE 20S THE REMAINDER OF THE NIGHT. TRENDED
TOWARDS COOLER MET GUIDANCE WEDNESDAY AS POTENTIAL FOR STRATOCU
DEVELOPMENT MENTIONED ABOVE MAY STUNT TEMP RISES A BIT. LEANED
TOWARDS MAVMOS GUIDANCE THROUGH THE REMAINDER OF THE SHORT TERM WITH
HIGH TEMPERATURES CLIMBING INTO THE 40S THURSDAY AS LOW LEVEL
SOUTHWESTERLY FLOW PUMPS WARMER AIR INTO THE OHIO VALLEY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS ARE STILL SUPPORTING A DRY EXTENDED FORECAST. A LOW PRESSURE
SYSTEM AND ASSOCIATED COLD FRONT ARE STILL PROGGED TO MOVE ACROSS
THE GREAT LAKES REGION ON SATURDAY...BUT MOISTURE CONTINUES TO BE
LACKING. PLUS...THE ONLY GULF MOISTURE THAT WILL BE ADVECTED AHEAD
OF THE FRONT WILL BE AFTER IT/S THROUGH CENTRAL INDIANA. SO...REMOVED
MENTION OF POPS ACROSS THE SOUTHEAST QUADRANT OF FORECAST AREA ON
SATURDAY. BEYOND THAT...MODELS HAVE FALLEN OUT OF AGREEMENT IN
REGARD TO A LOW PRESSURE SYSTEM ON MONDAY AND TUESDAY.
ORIGINALLY...THEY BOTH INDICATED A TRACK ACROSS THE DEEP SOUTH.
HOWEVER...THE EURO IS PULLING IT MUCH FURTHER SOUTH NOW...WHILE THE
GFS IS SHOWING A VERY BROAD UPPER LEVEL TROUGH OVER MUCH OF THE OHIO
AND TENNESSEE VALLEYS...AND DOWN INTO THE DEEP SOUTH. AS A
RESULT...WILL NOT DEVIATE FROM DRY INITIALIZATION NUMBERS WITH THIS
MUCH INCONSISTENCY.
TEMPS...TRENDED FRIDAY/S HIGHS ON THE WARMER SIDE WITH DECENT
SOUTHWEST FLOW AHEAD OF AFOREMENTIONED COLD FRONT...AND BUMPED UP
FRIDAY NIGHT/S LOWS A FEW DEGREES AS WELL TO ACCOUNT FOR INCREASED
CLOUD COVER. OTHERWISE...STUCK WITH INITIALIZATION NUMBERS FOR THE
REMAINDER OF EXTENDED PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 03/09Z TAF UPDATE/...
UPDATE...
NO CHANGES.
PREVIOUS DISCUSSION...
FINALLY...AS EXPECTED THE MAJORITY OF THE SCATTERED SNOW SHOWER
ACTIVITY HAS ABATED. SNOW SHOWERS MAY IMPACT THE NE CORRIDOR OF
THE FORECAST AREA...THANKS TO SOME LAKE EFFECT ACTION...BUT THIS
SHOULD STAY NORTHEAST OF THE FORECAST TERMINALS. THIS LAKE EFFECT
ACTIVITY SHOULD BE MONITORED IN THE RARE CASE IS MATRICULATES
DOWN TOWARD KIND. OTHERWISE...BKN-OVC MID LVL CLOUDS WILL BEGIN TO
SCATTERED OUT LATER THIS MORNING. PRESSURE GRADIENT WILL
GRADUALLY DECREASE OVERNIGHT AND WINDS BY LATER THIS MORNING WILL
BE 10 KNOTS OR LESS AT ALL SITES.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....TDUD
AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
930 AM EST SUN JAN 1 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS CENTRAL INDIANA THIS
MORNING...USHERING IN MUCH COLDER ARCTIC AIR FOR THE FIRST FEW DAYS
OF THE NEW YEAR ALONG WITH STRONG WINDS. SOME LIGHT PRECIPITATION
MAY ACCOMPANY THE FRONTAL PASSAGE. CHANCES FOR FLURRIES AND LIGHT
SNOW SHOWERS COME MONDAY INTO EARLY TUESDAY ACROSS NORTHERN AND
EASTERN PORTIONS OF THE FORECAST AREA AS A STRONG UPPER LEVEL
DISTURBANCE OVER THE GREAT LAKES PULLS AWAY SLOWLY. HIGH PRESSURE
WILL RETURN ON TUESDAY BRINGING DRY COLD WEATHER. A SLOW WARMING
TREND DURING THE SECOND HALF OF THE WEEK WILL BRING TEMPERATURES
BACK TO ABOVE NORMAL LEVELS BY FRIDAY.
&&
.NEAR TERM /TODAY/...
SURFACE ANALYSIS AS OF 08Z PLACES LOW PRESSURE OVER FAR EASTERN IOWA
WITH A COLD FRONT EXTENDING SOUTH THROUGH CENTRAL ILLINOIS. WARM
ADVECTION AND ISENTROPIC LIFT AHEAD OF THE FRONT HAD ENABLED
STRATOCU TO FORM OVER THE EASTERN HALF OF THE FORECAST AREA.
TEMPERATURES HAVE WARMED STEADILY SINCE MIDNIGHT IN THE WARM
ADVECTION...WITH MUCH OF THE FORECAST AREA IN THE 40S.
FOCUS FOR TODAY IS ON TEMPS AND WIND GUSTS AS THE FRONT SWEEPS
ACROSS THE REGION THIS MORNING. EXTRAPOLATION TO CURRENT OBS BRINGS
THE FRONT ACROSS THE STATE LINE AND INTO THE WABASH VALLEY AROUND
1130-12Z...PROGRESSING EASTWARD ACROSS THE FORECAST AREA THROUGHOUT
THE MORNING. STRONGER GUSTS ARE POST-FRONTAL AND WITH THAT IN
MIND...WILL BE DELAYING THE START TIME OF THE WIND ADVISORY ACROSS
THE WABASH VALLEY BACK TO 12Z TO MATCH UP WITH THE REST OF THE
HEADLINE ACROSS CENTRAL INDIANA. SEEING LIGHT PRECIP EARLY THIS
MORNING ACROSS CENTRAL MISSOURI WITHIN AREA OF DEEPER MOISTURE RIGHT
BEHIND THE FRONT. SHORT RANGE MODEL GUIDANCE FAIRLY CONSISTENT IN
BRINGING THIS AREA OF MOISTURE ACROSS THE FORECAST AREA THROUGH
18Z...WITH POTENTIAL FOR LIGHT RAIN OR SPRINKLES. AS THE COLDER AIR
STEADILY SPILLS INTO THE REGION...MAY SEE A FEW SNOWFLAKES MIX IN
WITH THE RAIN BEFORE THE PRECIP CHANCES END. WILL CONTINUE TO CARRY
LOW CHANCE POPS ACROSS NORTHERN HALF OF THE FORECAST AREA THROUGH
18Z WHERE DEEPEST MOISTURE WILL RESIDE.
MUCH GREATER FOCUS WILL BE ON THE GUSTY WINDS...ESPECIALLY BY THIS
AFTERNOON AS LOW LEVEL MIXING MAY EXTEND ALL THE WAY UP TO AROUND
5-6KFT AS COLD ADVECTION INTENSIFIES INTO THE REGION. THINK POTENTIAL
FOR STRONGEST WIND GUSTS WITHIN THE ADVISORY CATEGORY WILL TAKE
PLACE AFTER 16Z...PARTICULARLY IF CLOUDS CAN SCATTER FOR A PERIOD OF
TIME WHICH WOULD ENHANCE THE MIXING HEIGHTS INTO THE BOUNDARY LAYER.
THIS SEEMS PLAUSIBLE AS THE DRIER ARCTIC AIRMASS SURGES INTO THE
FORECAST AREA THIS AFTERNOON AND MODEL SOUNDINGS ARE SUPPORTIVE OF A
FEW HOURS WITH PARTLY CLOUDY OR POSSIBLY EVEN MOSTLY SUNNY SKIES.
POTENTIAL CONTINUES FOR WESTERLY SUSTAINEDS AT 20-30MPH WITH MAX
WIND GUSTS AROUND 50MPH.
TEMPS...HIGHS WILL TAKE PLACE DURING THE MORNING PRIOR TO FRONTAL
PASSAGE. UTILIZED RUC GUIDANCE TO GET THE NON-DIURNAL TREND FOR THE
DAY AND CAPTURE TEMPS THIS MORNING AHEAD OF THE FRONT. ENDED UP
SEVERAL DEGREES ABOVE GUIDANCE FOR HIGHS AS MOST LOCATIONS SHOULD BE
IN THE MID AND UPPER 40S BEFORE THE FRONT PASSES. MORE SUBSTANTIAL
TEMP FALLS INTO THE LOWER AND MID 30S SHOULD HOLD OFF UNTIL THE
AFTERNOON AS STRONGER COLD ADVECTION ARRIVES.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON POTENTIAL FOR FLURRIES/LIGHT SNOW
SHOWERS THROUGH EARLY TUESDAY AS UPPER TROUGH DEEPENS OVER THE GREAT
LAKES AND MOVES ONLY SLOWLY OFF TO THE EAST.
WINDS WILL CONTINUE TO HOWL THIS EVENING WITH THE UPPER LEVELS
AMPLIFYING AS ADDITIONAL ENERGY DIVES INTO THE TROUGH. MODEL
SOUNDINGS CONTINUE TO SHOW MODEST MIXING THROUGH THE LOWER LEVELS
WELL INTO THE EVENING...WITH STRONGER WINDS WITHIN THE BOUNDARY
LAYER NOT SHIFTING EAST OF THE REGION UNTIL CLOSER TO MIDNIGHT. HAVE
THEREFORE CHOSEN TO EXTEND THE WIND ADVISORY THROUGH 03Z AS MAX
GUSTS MAY LINGER NEAR ADVISORY CRITERIA. GUSTS SHOULD SLOWLY WEAKEN
TO CLOSER TO 30-35MPH AFTER MIDNIGHT AS THE MIXING LEVEL DROPS. THE
AMPLIFICATION OF THE TROUGH ALOFT WILL ENABLE DEEPER LOW LEVEL
MOISTURE TO SPILL BACK SOUTH INTO THE FORECAST AREA WITH STRATOCU
EXPANDING ACROSS THE NORTHERN HALF OF THE FORECAST AREA.
PERSISTENT FORCING WITHIN THE MID LEVELS WILL FURTHER AMPLIFY THE
UPPER TROUGH INTO CENTRAL INDIANA ON MONDAY...BRINGING A VERY COLD
BLUSTERY DAY WITH AN ABUNDANCE OF CLOUD COVER. LOW LEVEL FLOW
LARGELY OUT OF THE W/NW SHOULD KEEP MORE PERSISTENT SNOW SHOWERS
CONFINED TO JUST FAR NORTHEAST COUNTIES OR POSSIBLY EVEN COMPLETELY
NORTH OF THE FORECAST AREA FOR MUCH OF THE DAY. WILL MAINTAIN
MENTION OF SCATTERED FLURRIES BACK WEST TO NEAR THE I-65 CORRIDOR
WITH THE FORCING ALOFT PRESENT. LOW LEVEL FLOW DOES VEER TO A MORE
NW DIRECTION MONDAY NIGHT...BUT OVERALL WIND PROFILES ARE NOT AS
FAVORABLE AS PREVIOUS MODEL GUIDANCE INDICATED IN BRINGING MORE
PERSISTENT SNOW SHOWERS INTO A LARGER PORTION OF THE FORECAST AREA.
MODELS CONTINUE TO ADVERTISE THE DEVELOPMENT OF A SINGLE DOMINANT
BAND OFF LAKE MICHIGAN MONDAY NIGHT/EARLY TUESDAY. LOW LEVEL WIND
TRAJECTORIES SUGGESTIVE OF BRINGING REMNANTS OF THE BAND INTO
DELAWARE/MADISON/RANDOLPH COUNTIES AND WILL CONTINUE WITH LOW CHANCE
POPS THROUGH TUESDAY MORNING IN THESE AREAS. AM NOT AS CONFIDENT IN
WESTERN EXTENT TO FLURRIES/LIGHT SNOW SHOWERS WITH TRAJECTORIES NOT
AS VEERED. WHILE PRESENCE OF THE FORCING ALOFT AND BACK SIDE UPPER
JET DIVING INTO THE TROUGH COULD BOTH BE FACTORS IN KEEPING FLURRIES
GOING FOR MUCH OF THE NIGHT ALL THE WAY BACK TO THE I-65 CORRIDOR...
HAVE ELECTED TO KEEP ANY MENTION OF PRECIP TO THE NORTHEAST OF THE
INDY METRO AND LAFAYETTE AREAS AT THIS TIME.
HIGH PRESSURE RIDGE FINALLY BUILDS IN TUESDAY WITH LOW LEVEL FLOW
BACKING AND WEAKENING. THIS WILL END ANY FLURRIES AND ALLOW LOW
CLOUDS TO SCATTER BY TUESDAY AFTERNOON. MAINLY CLEAR SKIES WILL
CONTINUE INTO TUESDAY EVENING BEFORE CLOUDS RETURN AS A WEAK
DISTURBANCE ALOFT MOVES INTO THE GREAT LAKES. NOT EXPECTING ANY
PRECIPITATION WITH THIS FEATURE AS FORCING REMAINS CONFINED WELL
NORTH OF THE REGION.
TEMPS...LEANED TOWARDS MET GUIDANCE THROUGH MONDAY NIGHT AS NAM
TRADITIONALLY SAMPLES ARCTIC AIRMASS BETTER THAN OTHER MODELS.
LEANED TOWARDS COOLER MOS FOR HIGHS ON TUESDAY AS TEMPS WILL LIKELY
HOLD IN THE MID 20S ACROSS MUCH OF THE REGION. TEMPS NOT LIKELY TO
FALL MUCH LOWER THAN 20 DEGREES TUESDAY NIGHT AS INCREASING CLOUDS
AND WARM ADVECTION TAKES ROOT AHEAD OF THE UPPER LEVEL DISTURBANCE
MOVING INTO THE GREAT LAKES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
STRONG RIDGING ALOFT WILL DOMINATE THE MAJORITY OF THE EXTENDED
FORECAST. AS A RESULT...DRY CONDITIONS WILL PREVAIL FROM WEDNESDAY
THROUGH FRIDAY. THE NEXT CHANCE FOR ANY PRECIP WILL BE AT THE END
OF THE LONG TERM PERIOD WHEN A SYSTEM TRACKS ACROSS THE GREAT LAKES
REGION. HOWEVER...MODELS ARE STILL KEEPING THE BEST LIFT AND PRECIP
NORTH OF CENTRAL INDIANA. INITIALIZATION IS ONLY SHOWING SLIGHT
CHANCE POPS ON SATURDAY...WHICH STILL LOOKS REASONABLE. FURTHER
OUT...THE NEXT SYSTEM TO WATCH WILL BE COMING OUT OF THE PLAINS ON
SUNDAY. AT THIS TIME...INITIALIZATION NUMBERS ARE FAVORING THE GFS.
THE EURO IS NOT EVEN HINTING AT A DISTURBANCE AT THIS TIME AND
CONTINUES WITH ZONAL FLOW UNTIL DAY 9.
TEMPS WILL CLIMB BACK TO ABOVE NORMAL AND REMAIN THAT WAY FOR THE
DURATION OF THE EXTENDED PERIOD. HIGHS WILL TOP OFF IN THE 40S...AND
EVEN LOW 50S BY FRIDAY. OVERNIGHT LOWS WILL ALSO BE ABOVE NORMAL
WITH READINGS IN THE UPPER 20S/LOW 30S.
&&
.AVIATION /DISCUSSION FOR THE 01/15Z KIND TAF UPDATE/...
MINOR TWEEKS MADE IN KIND TAF PER OBSERVATIONS. OTHERWISE...NO OTHER
CHANGES NEEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION FOLLOW...
THE MAIN CONCERN OF TAF PERIOD CONTINUES TO BE THE STRONG WINDS.
CONDITIONS WILL GENERALLY BE VFR CATEGORY FOR ENTIRE PERIOD EXCEPT
FOR SOME BRIEF MVFR CEILINGS THIS MORNING WITH FRONTAL PASSAGE.
SO...FOCUS TURNS TO THE GUSTY WINDS. WINDS ARE VEERING TO THE WEST
AT THIS TIME AS COLD FRONT APPROACHES KLAF...AND WILL REMAIN
WESTERLY FOR DURATION OF TAF PERIOD. WINDS WILL REALLY RAMP UP BY
MID MORNING AND WILL BE THE STRONGEST THROUGH THIS AFTERNOON WITH
SUSTAINED SPEEDS OF 24 TO 28 KTS AND GUSTS AS HIGH AS 40 KTS.
THERE COULD STILL BE SOME WIND SHEAR ISSUES AT FIRST...BUT THIS
SHOULD BE PRETTY SHORT-LIVED AS SURFACE WINDS INCREASE QUICKLY.
WINDS WILL WEAKEN A TAD THIS EVENING...BUT WILL REMAIN STRONG
THROUGH TOMORROW MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....TDUD
AVIATION...TDUD/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
639 AM EST SUN JAN 1 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP ACROSS CENTRAL INDIANA THIS
MORNING...USHERING IN MUCH COLDER ARCTIC AIR FOR THE FIRST FEW DAYS
OF THE NEW YEAR ALONG WITH STRONG WINDS. SOME LIGHT PRECIPITATION
MAY ACCOMPANY THE FRONTAL PASSAGE. CHANCES FOR FLURRIES AND LIGHT
SNOW SHOWERS COME MONDAY INTO EARLY TUESDAY ACROSS NORTHERN AND
EASTERN PORTIONS OF THE FORECAST AREA AS A STRONG UPPER LEVEL
DISTURBANCE OVER THE GREAT LAKES PULLS AWAY SLOWLY. HIGH PRESSURE
WILL RETURN ON TUESDAY BRINGING DRY COLD WEATHER. A SLOW WARMING
TREND DURING THE SECOND HALF OF THE WEEK WILL BRING TEMPERATURES
BACK TO ABOVE NORMAL LEVELS BY FRIDAY.
&&
.NEAR TERM /TODAY/...
SURFACE ANALYSIS AS OF 08Z PLACES LOW PRESSURE OVER FAR EASTERN IOWA
WITH A COLD FRONT EXTENDING SOUTH THROUGH CENTRAL ILLINOIS. WARM
ADVECTION AND ISENTROPIC LIFT AHEAD OF THE FRONT HAD ENABLED
STRATOCU TO FORM OVER THE EASTERN HALF OF THE FORECAST AREA.
TEMPERATURES HAVE WARMED STEADILY SINCE MIDNIGHT IN THE WARM
ADVECTION...WITH MUCH OF THE FORECAST AREA IN THE 40S.
FOCUS FOR TODAY IS ON TEMPS AND WIND GUSTS AS THE FRONT SWEEPS
ACROSS THE REGION THIS MORNING. EXTRAPOLATION TO CURRENT OBS BRINGS
THE FRONT ACROSS THE STATE LINE AND INTO THE WABASH VALLEY AROUND
1130-12Z...PROGRESSING EASTWARD ACROSS THE FORECAST AREA THROUGHOUT
THE MORNING. STRONGER GUSTS ARE POST-FRONTAL AND WITH THAT IN
MIND...WILL BE DELAYING THE START TIME OF THE WIND ADVISORY ACROSS
THE WABASH VALLEY BACK TO 12Z TO MATCH UP WITH THE REST OF THE
HEADLINE ACROSS CENTRAL INDIANA. SEEING LIGHT PRECIP EARLY THIS
MORNING ACROSS CENTRAL MISSOURI WITHIN AREA OF DEEPER MOISTURE RIGHT
BEHIND THE FRONT. SHORT RANGE MODEL GUIDANCE FAIRLY CONSISTENT IN
BRINGING THIS AREA OF MOISTURE ACROSS THE FORECAST AREA THROUGH
18Z...WITH POTENTIAL FOR LIGHT RAIN OR SPRINKLES. AS THE COLDER AIR
STEADILY SPILLS INTO THE REGION...MAY SEE A FEW SNOWFLAKES MIX IN
WITH THE RAIN BEFORE THE PRECIP CHANCES END. WILL CONTINUE TO CARRY
LOW CHANCE POPS ACROSS NORTHERN HALF OF THE FORECAST AREA THROUGH
18Z WHERE DEEPEST MOISTURE WILL RESIDE.
MUCH GREATER FOCUS WILL BE ON THE GUSTY WINDS...ESPECIALLY BY THIS
AFTERNOON AS LOW LEVEL MIXING MAY EXTEND ALL THE WAY UP TO AROUND
5-6KFT AS COLD ADVECTION INTENSIFIES INTO THE REGION. THINK POTENTIAL
FOR STRONGEST WIND GUSTS WITHIN THE ADVISORY CATEGORY WILL TAKE
PLACE AFTER 16Z...PARTICULARLY IF CLOUDS CAN SCATTER FOR A PERIOD OF
TIME WHICH WOULD ENHANCE THE MIXING HEIGHTS INTO THE BOUNDARY LAYER.
THIS SEEMS PLAUSIBLE AS THE DRIER ARCTIC AIRMASS SURGES INTO THE
FORECAST AREA THIS AFTERNOON AND MODEL SOUNDINGS ARE SUPPORTIVE OF A
FEW HOURS WITH PARTLY CLOUDY OR POSSIBLY EVEN MOSTLY SUNNY SKIES.
POTENTIAL CONTINUES FOR WESTERLY SUSTAINEDS AT 20-30MPH WITH MAX
WIND GUSTS AROUND 50MPH.
TEMPS...HIGHS WILL TAKE PLACE DURING THE MORNING PRIOR TO FRONTAL
PASSAGE. UTILIZED RUC GUIDANCE TO GET THE NON-DIURNAL TREND FOR THE
DAY AND CAPTURE TEMPS THIS MORNING AHEAD OF THE FRONT. ENDED UP
SEVERAL DEGREES ABOVE GUIDANCE FOR HIGHS AS MOST LOCATIONS SHOULD BE
IN THE MID AND UPPER 40S BEFORE THE FRONT PASSES. MORE SUBSTANTIAL
TEMP FALLS INTO THE LOWER AND MID 30S SHOULD HOLD OFF UNTIL THE
AFTERNOON AS STRONGER COLD ADVECTION ARRIVES.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON POTENTIAL FOR FLURRIES/LIGHT SNOW
SHOWERS THROUGH EARLY TUESDAY AS UPPER TROUGH DEEPENS OVER THE GREAT
LAKES AND MOVES ONLY SLOWLY OFF TO THE EAST.
WINDS WILL CONTINUE TO HOWL THIS EVENING WITH THE UPPER LEVELS
AMPLIFYING AS ADDITIONAL ENERGY DIVES INTO THE TROUGH. MODEL
SOUNDINGS CONTINUE TO SHOW MODEST MIXING THROUGH THE LOWER LEVELS
WELL INTO THE EVENING...WITH STRONGER WINDS WITHIN THE BOUNDARY
LAYER NOT SHIFTING EAST OF THE REGION UNTIL CLOSER TO MIDNIGHT. HAVE
THEREFORE CHOSEN TO EXTEND THE WIND ADVISORY THROUGH 03Z AS MAX
GUSTS MAY LINGER NEAR ADVISORY CRITERIA. GUSTS SHOULD SLOWLY WEAKEN
TO CLOSER TO 30-35MPH AFTER MIDNIGHT AS THE MIXING LEVEL DROPS. THE
AMPLIFICATION OF THE TROUGH ALOFT WILL ENABLE DEEPER LOW LEVEL
MOISTURE TO SPILL BACK SOUTH INTO THE FORECAST AREA WITH STRATOCU
EXPANDING ACROSS THE NORTHERN HALF OF THE FORECAST AREA.
PERSISTENT FORCING WITHIN THE MID LEVELS WILL FURTHER AMPLIFY THE
UPPER TROUGH INTO CENTRAL INDIANA ON MONDAY...BRINGING A VERY COLD
BLUSTERY DAY WITH AN ABUNDANCE OF CLOUD COVER. LOW LEVEL FLOW
LARGELY OUT OF THE W/NW SHOULD KEEP MORE PERSISTENT SNOW SHOWERS
CONFINED TO JUST FAR NORTHEAST COUNTIES OR POSSIBLY EVEN COMPLETELY
NORTH OF THE FORECAST AREA FOR MUCH OF THE DAY. WILL MAINTAIN
MENTION OF SCATTERED FLURRIES BACK WEST TO NEAR THE I-65 CORRIDOR
WITH THE FORCING ALOFT PRESENT. LOW LEVEL FLOW DOES VEER TO A MORE
NW DIRECTION MONDAY NIGHT...BUT OVERALL WIND PROFILES ARE NOT AS
FAVORABLE AS PREVIOUS MODEL GUIDANCE INDICATED IN BRINGING MORE
PERSISTENT SNOW SHOWERS INTO A LARGER PORTION OF THE FORECAST AREA.
MODELS CONTINUE TO ADVERTISE THE DEVELOPMENT OF A SINGLE DOMINANT
BAND OFF LAKE MICHIGAN MONDAY NIGHT/EARLY TUESDAY. LOW LEVEL WIND
TRAJECTORIES SUGGESTIVE OF BRINGING REMNANTS OF THE BAND INTO
DELAWARE/MADISON/RANDOLPH COUNTIES AND WILL CONTINUE WITH LOW CHANCE
POPS THROUGH TUESDAY MORNING IN THESE AREAS. AM NOT AS CONFIDENT IN
WESTERN EXTENT TO FLURRIES/LIGHT SNOW SHOWERS WITH TRAJECTORIES NOT
AS VEERED. WHILE PRESENCE OF THE FORCING ALOFT AND BACK SIDE UPPER
JET DIVING INTO THE TROUGH COULD BOTH BE FACTORS IN KEEPING FLURRIES
GOING FOR MUCH OF THE NIGHT ALL THE WAY BACK TO THE I-65 CORRIDOR...
HAVE ELECTED TO KEEP ANY MENTION OF PRECIP TO THE NORTHEAST OF THE
INDY METRO AND LAFAYETTE AREAS AT THIS TIME.
HIGH PRESSURE RIDGE FINALLY BUILDS IN TUESDAY WITH LOW LEVEL FLOW
BACKING AND WEAKENING. THIS WILL END ANY FLURRIES AND ALLOW LOW
CLOUDS TO SCATTER BY TUESDAY AFTERNOON. MAINLY CLEAR SKIES WILL
CONTINUE INTO TUESDAY EVENING BEFORE CLOUDS RETURN AS A WEAK
DISTURBANCE ALOFT MOVES INTO THE GREAT LAKES. NOT EXPECTING ANY
PRECIPITATION WITH THIS FEATURE AS FORCING REMAINS CONFINED WELL
NORTH OF THE REGION.
TEMPS...LEANED TOWARDS MET GUIDANCE THROUGH MONDAY NIGHT AS NAM
TRADITIONALLY SAMPLES ARCTIC AIRMASS BETTER THAN OTHER MODELS.
LEANED TOWARDS COOLER MOS FOR HIGHS ON TUESDAY AS TEMPS WILL LIKELY
HOLD IN THE MID 20S ACROSS MUCH OF THE REGION. TEMPS NOT LIKELY TO
FALL MUCH LOWER THAN 20 DEGREES TUESDAY NIGHT AS INCREASING CLOUDS
AND WARM ADVECTION TAKES ROOT AHEAD OF THE UPPER LEVEL DISTURBANCE
MOVING INTO THE GREAT LAKES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
STRONG RIDGING ALOFT WILL DOMINATE THE MAJORITY OF THE EXTENDED
FORECAST. AS A RESULT...DRY CONDITIONS WILL PREVAIL FROM WEDNESDAY
THROUGH FRIDAY. THE NEXT CHANCE FOR ANY PRECIP WILL BE AT THE END
OF THE LONG TERM PERIOD WHEN A SYSTEM TRACKS ACROSS THE GREAT LAKES
REGION. HOWEVER...MODELS ARE STILL KEEPING THE BEST LIFT AND PRECIP
NORTH OF CENTRAL INDIANA. INITIALIZATION IS ONLY SHOWING SLIGHT
CHANCE POPS ON SATURDAY...WHICH STILL LOOKS REASONABLE. FURTHER
OUT...THE NEXT SYSTEM TO WATCH WILL BE COMING OUT OF THE PLAINS ON
SUNDAY. AT THIS TIME...INITIALIZATION NUMBERS ARE FAVORING THE GFS.
THE EURO IS NOT EVEN HINTING AT A DISTURBANCE AT THIS TIME AND
CONTINUES WITH ZONAL FLOW UNTIL DAY 9.
TEMPS WILL CLIMB BACK TO ABOVE NORMAL AND REMAIN THAT WAY FOR THE
DURATION OF THE EXTENDED PERIOD. HIGHS WILL TOP OFF IN THE 40S...AND
EVEN LOW 50S BY FRIDAY. OVERNIGHT LOWS WILL ALSO BE ABOVE NORMAL
WITH READINGS IN THE UPPER 20S/LOW 30S.
&&
.AVIATION /DISCUSSION FOR THE 01/12Z TAF ISSUANCE/...
THE MAIN CONCERN OF TAF PERIOD CONTINUES TO BE THE STRONG WINDS.
CONDITIONS WILL GENERALLY BE VFR CATEGORY FOR ENTIRE PERIOD EXCEPT
FOR SOME BRIEF MVFR CEILINGS THIS MORNING WITH FRONTAL PASSAGE.
SO...FOCUS TURNS TO THE GUSTY WINDS. WINDS ARE VEERING TO THE WEST
AT THIS TIME AS COLD FRONT APPROACHES KLAF...AND WILL REMAIN
WESTERLY FOR DURATION OF TAF PERIOD. WINDS WILL REALLY RAMP UP BY
MID MORNING AND WILL BE THE STRONGEST THROUGH THIS AFTERNOON WITH
SUSTAINED SPEEDS OF 24 TO 28 KTS AND GUSTS AS HIGH AS 40 KTS.
THERE COULD STILL BE SOME WIND SHEAR ISSUES AT FIRST...BUT THIS
SHOULD BE PRETTY SHORT-LIVED AS SURFACE WINDS INCREASE QUICKLY.
WINDS WILL WEAKEN A TAD THIS EVENING...BUT WILL REMAIN STRONG
THROUGH TOMORROW MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....TDUD
AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1112 AM CST SUN JAN 1 2012
.UPDATE...
STRONG SHORT WAVE OVER MN IN CYCLONIC FLOW ALOFT...AS SEEN ON WATER
VAPOR...DROPPING ACROSS THE AREA THIS AFTERNOON SUPPORTS POTENTIAL
FOR FLURRIES OVER NORTHERN PORTIONS OF THE CWFA THROUGH 00Z.
WITH RESPECT TO WINDS...PEAK MIXING ONGOING NOW. MAIN QUESTION FOR
THE AFTERNOON AND EVENING WILL BE DURATION OF STRONG WINDS. NAM
AND RUC TROP PRESSURE FIELDS INDICATE TROP FOLD TO CROSS NORTHERN
ILLINOIS THIS AFTERNOON AND PEAK WINDS EXPECTED IN NORTHWEST
ILLINOIS COUNTIES BETWEEN 18Z AND 22Z. CURRENT THINKING IS THAT
WHILE SUSTAINED WINDS CONTINUE...ENCROACHING CLOUDS WILL TEMPER
MIXING AND THUS THE INTENSITY OF THE GUSTS BY LATE AFTERNOON AND
SIMILARLY WITH THE LOSS OF HEATING THIS EVENING.
WIND HEADLINES WILL CONTINUE FOR THE AFTERNOON WITH ADJUSTMENTS
POSSIBLE FOR THIS EVENING AND OVERNIGHT DEPENDING ON HOW THE
AFTERNOON EVOLVES.
&&
.AVIATION...
A STRONG STORM SYSTEM CROSSING THE MIDWEST HAS LIFTED INTO THE
GREAT LAKES. IN ITS WAKE...STRONG NORTHWESTERLY LOW LEVEL WINDS
ARE BATTERING THE ENTIRE UPPER MIDWEST. IN EASTERN IOWA AND
WESTERN ILLINOIS...SUSTAINED WINDS OF 30 TO 40 MPH WILL CONTINUE THROUGH
THE DAY WITH PEAK WINDS EXPECTED TO OCCUR THIS AFTERNOON WITH
GUSTS IN SOME SPOTS TOPPING 50 MPH. GUSTS WILL DIMINISH AFTER
SUNSET...ALTHOUGH SUSTAINED WINDS WILL REMAIN HIGH THROUGH THE
NIGHT AND BEGIN TO GRADUALLY DIMINISH MONDAY. WITH DAYTIME HEATING...WIND
GUSTS WILL RETURN MONDAY ALTHOUGH NOT AS STRONG AS TODAY.
OTHERWISE...AN AREA OF MVFR CIGS WILL OVERSPREAD THE AREA FROM
THE NORTH THIS AFTERNOON AND LINGER INTO THE EVENING BEFORE
SHIFTING OFF TO THE EAST OVERNIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLINTON-DES MOINES-
JACKSON-LEE-SCOTT.
HIGH WIND WARNING UNTIL MIDNIGHT CST TONIGHT FOR BENTON-BUCHANAN-
CEDAR-DELAWARE-DUBUQUE-HENRY IA-IOWA-JEFFERSON-JOHNSON-
JONES-KEOKUK-LINN-LOUISA-MUSCATINE-VAN BUREN-WASHINGTON.
IL...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLARK-SCOTLAND.
&&
$$
DMD/SHEETS/DMD
AREA FORECAST DISCUSSION
NWS GRAY ME
942 PM EST MON JAN 2 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH NEW ENGLAND TONIGHT USHERING MUCH
COLDER AIR INTO THE REGION ON GUSTY NORTHWEST WINDS. THE COLD
BLUSTERY WEATHER WILL LAST THROUGH WEDNESDAY. HIGH PRESSURE WILL
CREST OVER THE REGION WEDNESDAY ALLOWING TEMPERATURES TO BEGIN
TO MODERATE. PRECIPITATION WILL RETURN TO THE FORECAST THURSDAY
AND FRIDAY AS AN UPPER LEVEL DISTURBANCE PASSES OVERHEAD.
&&
.NEAR TERM /THROUGH TONIGHT/...
940 PM UPDATE...TWEAKED POPS...WINDS...AND TEMPS BASED ON LATEST
TRENDS IN DATA. AS OF 930 PM...ARCTIC COLD FRONT WAS MOVING ACROSS
THE WESTERN MAINE AND NORTHERN NEW HAMPSHIRE MOUNTAINS. THIS FRONT
IS ACCOMPNAIED BY A LINE OF SNOW SQUALLS WITH VSBYS AROUND 1/4 MILE
AND BRIEF WIND GUSTS TO AROUND 30 MPH. THE HRRR MODEL IS DOING A
FINE JOB OF CAPTURING THIS FEATURE. WE HAVE USED SPECIAL WEATHER
STATEMENTS TO COVER THIS. THIS LINE OF SQUALLS SHOULD WEAKEN AS IT
APPROACHES THE COASTAL PLAIN DUE TO THE EFFECTS OF DOWNSLOPING AND
DRIER BOUNDARY LAYER AIR...HOWEVER...WILL CONTINUE TO WATCH IT/S
PROGRESS.
700 PM UPDATE...FORECAST REMAINS ON TRACK. OCCASIONAL SNOW SHOWERS
CONTINUE ACROSS NORTHERN ZONES AND THESE SHOULD CONTINUE FOR THE
NEXT SEVERAL HOURS BEFORE THE ARCTIC FRONT MOVES THROUGH.
OTHERWISE...JUST A FEW TWEAKS TO WINDS...SKY...AND TEMPS.
PREV DISC...
AN IMPRESSIVE NEGATIVELY TILTED UPPER LEVEL TROUGH IS NOW
DOMINATING MUCH OF THE EASTERN CONUS. SHORT WAVE ENERGY ROTATING
AROUND THE EASTERN PERIPHERY OF THE TROUGH ALONG WITH LAKE EFFECT
PROCESSES HAVE BEEN PRODUCING RAIN AND SNOW SHOWERS FROM NEW YORK
EASTWARD INTO MAINE TODAY. THIS TREND WILL CONTINUE TONIGHT AND
THE WHITE MOUNTAINS WILL SEE ANOTHER 1-3 INCHES OVERNIGHT. THE
HRRR MODEL DIMINISHES...BUT DOES NOT END...THE SHOWER ACTIVITY
TOWARDS MORNING AND HAVE FOLLOWED THIS TREND. COLD FRONT PUSHES
OFFSHORE OVERNIGHT WITH GUSTY WESTERLY WINDS VEERING TOWARDS
DAYBREAK. LOWS WILL RANGE FROM THE SINGLE DIGITS ACROSS THE NORTH
TO THE 20S IN THE SOUTH.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
GUSTY NW WINDS WILL DEVELOP BEHIND THE FRONT WITH A COLD ARCTIC
AIRMASS SLOWLY SEEPING INTO THE NORTHEAST THROUGHOUT THE DAY.
TEMPERATURES MAY RISE A FEW DEGREES AT FIRST BUT WILL DROP
QUICKLY FROM MID MORNING ON. HIGHS TOMORROW WILL BE AROUND +10
DEGREES ACROSS THE NORTH TO THE LOWER 20S IN THE SOUTH. UPSLOPE
SHOWERS WILL CONTINUE BUT WILL BE WANING WITH PERHAPS ANOTHER INCH
FALLING ACROSS THE HIGHER TERRAIN. TOMORROW NIGHT ZERO DEGREES
WILL BE COMMON ALONG THE COAST WITH -10F AND LOWER ACROSS THE
FOOTHILLS AND MOUNTAINS. WINDS WILL BE RELAXING BY THIS POINT BUT
A WIND CHILL ADVISORY WILL LIKELY BE REQUIRED.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
LARGE UPPER TROUGH EXITS TO THE EAST AND IS QUICKLY REPLACED BY
ANOTHER TROUGH. WEAK SURFACE HIGH PRESSURE MOVES ACROSS THE AREA
ON WEDNESDAY WITH COLD BUT MODERATING TEMPERATURES. ANOTHER COLD
FRONT PUSHES COLD AIR BACK INTO THE AREA THURSDAY. BY THIS TIME...
FLOW ALOFT BECOMES MORE ZONAL WITH WEAK IMPULSES PASSING THROUGH
THE FLOW. WARM FRONT CROSSES THE AREA FRIDAY INTO FRIDAY NIGHT...
WITH SOME LIGHT SNOW POSSIBLE IN THE WARM ADVECTION PATTERN.
WARMER AIR RETURNS ON SATURDAY... WITH HIGHS IN SOUTHERN AREAS
REACHING THE 40S AND MOST EVERYONE RISING ABOVE FREEZING FOR THE
FIRST TIME THIS WEEK. ANOTHER COLD FRONT PUSHES INTO THE AREA ON
SUNDAY BRINGING COLDER AIR BACK IN.
OVERALL DRY AND COLD... WITH A POTENTIAL WARM UP LATE IN THE WEEK.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
SHORT TERM...GUSTY WESTERLY WINDS WILL DIMINISH SOME TONIGHT
BEFORE VEERING TOMORROW MORNING BEHIND A COLD FRONT. EXPECT GUSTY
NW WINDS THROUGHOUT THE DAY. MOST SITES WILL REMAIN VFR BUT KHIE
AND KLEB MAY SEE BRIEF MVFR IN SNOW SHOWERS.
LONG TERM...VFR CONDITIONS THROUGH MUCH OF THE WEEK. MAY SEE BRIEF
MVFR CONDITIONS ON THURSDAY AS ANOTHER FRONT PUSHES THROUGH. AND
FRIDAY MAY HAVE MVFR OR IFR CONDITIONS AS A WARM FRONT MOVES
NORTHWARD AND SPREADS CLOUDS AND LIGHT SNOW INTO THE REGION.
&&
.MARINE...
SHORT TERM...SMALL CRAFT ISSUED. GALE HAS EXPIRED. A COLD FRONT WILL
MOVE THROUGH TOWARDS DAYBREAK AND THIS COULD CONTRIBUTE SOME GUSTS
UP TO 30 KT. WAVES WILL DECREASE FROM 5 TO 8 FT TO 3 TO 5 FT TOWARDS
MORNING.
LONG TERM...GENERALLY QUIET CONDITIONS EXPECTED OVER THE WATERS.
LOW PRESSURE DEVELOPS OFFSHORE ON TUESDAY BUT TRACKS WELL TO THE
SOUTHEAST OF THE GULF OF MAINE. GENERALLY LIGHT WINDS EXPECTED BUT
WINDS MAY REACH 25 KT AS A COLD FRONT MOVES THROUGH ON THURSDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ153.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ150>152-154.
&&
$$
NEAR TERM...EKSTER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1159 AM EST SUN JAN 1 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD BRIEFLY ACROSS THE REGION TODAY. AN OCCLUDED
FRONT WILL APPROACH FROM THE WEST THIS EVENING AND CROSS THE
REGION EARLY MONDAY MORNING...FOLLOWED BY A STRONG ARCTIC FRONT
LATE MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...LOW CLOUDS ARE HANGING TOUGH ACROSS MUCH OF THE FORECAST
AREA...AND IN FACT STRATOCUMULUS HAVE REDEVELOPED ACROSS PORTIONS
OF DOWNEAST MAINE THAT HAD CLEARED EARLIER. HAVE THEREFORE
INCREASED CLOUD COVER THROUGH MUCH OF THIS AFTERNOON AND THEN
BEGIN TO CLEAR THINGS OUT LATE. OTHERWISE NO OTHER CHANGES NEEDED.
PREVIOUS DISCUSSION...CLOUDS HANGING ON ACROSS MUCH OF
THE CWA THIS MORNING AS EVIDENT FROM THE LATEST IR SATL IMAGERY.
MOISTURE HANGING ON BELOW 925MBS W/AIRMASS DRY ABOVE THIS LAYER.
INVERSION IS IN PLACE AND IS SHOWN TO HANG ON FOR A WHILE THIS
MORNING PER THE LATEST RUC SOUNDINGS WHICH IS SUPPORT BY THE 00Z
NAM. A W FLOW TAKES OVER LATER THIS MORNING HELPING TO ERODE
CLOUDS ACROSS THE CENTRAL AND DOWNEAST REGION. ACROSS THE NORTH
AND WEST, CLOUDS COULD HANG ON LONGER W/INVERSION HANGING AS SHOWN
BY THE SOUNDINGS SHOWING MOISTURE STAYING TRAPPED AT AROUND
900MBS. DECIDED TO HANG ON TO SOME CLOUDS LONGER ACROSS THE
NORTHERN AND WESTERN AREAS INTO EARLY AFTERNOON W/MORE SUN ACROSS
THE CENTRAL AND DOWNEAST AREAS. OBVIOUSLY THIS WILL PLAY INTO THE
MAX TEMPERATURE FCST TODAY. ADJUSTED THE DAYCREW/S MAXES FOR TODAY
UPWARD ACROSS THE CWA W/UPPER 20S TO LOWER 30S ACROSS THE NORTH
AND WEST AND UPPER 30S TO LOWER 40S FOR CENTRAL AND DOWNEAST
AREAS.
TONIGHT COULD BE INTERESTING AS AN OCCLUDED FRONT APCHS FROM THE W
LATER TONIGHT W/PRECIP MOVING IN LATER TONIGHT. LATEST MDL
SOUNDINGS SHOW TEMPERATURES TO BE WARM ENOUGH ACROSS THE CENTRAL
AND DOWNEAST AREAS FOR MAINLY RAIN. ACROSS THE NORTHERN AND
WESTERN AREAS, THINGS LOOK TO BE DIFFERENT AS TEMPERATURES COOL
OFF EARLY TONIGHT AND THEN LEVEL OFF BEFORE RISING WELL AFTER
MIDNIGHT. WX ELEMENT IN THESE AREAS WILL BE IN THE FORM OF SOME
SNOW BUT A TRANSITION TO FREEZING PRECIP IS POSSIBLE. THE NAM AND GFS
BOTH SHOW A WARM LAYER SETTING UP AGAIN FROM 925-850MBS W/A COLD
LAYER AT THE SFC. THIS WILL SET THE STAGE FOR ANOTHER FRZA EVENT.
THE TIMING LOOKS TO BE BRIEF W/FZRA/FZDZ. THERE ALSO LOOKS TO BE A
PERIOD OF SLEET POSSIBLE. BEST SNOW ACCUMULATION WILL BE ACROSS
THE FAR NORTH AND WEST MAINLY NORTH AND WEST OF CAR,PQI & HUL. THE
PRECIP FROM THICKNESS TOOL WAS USED FOR THE WX ELEMENT. QPF IS A
BLEND OF HPC/GFS AND THE NAM WHICH SHOWS THE HIGHEST AREAS ACROSS
DOWNEAST AND AND EASTERN SECTIONS. ADDED SOME ICE ACCUMULATION
MAINLY FOR THE NORTH AND WEST W/<.10". DECIDED TO HOLD OFF ON ANY
WINTER WEATHER ADVISORIES AS THIS LOOKS TO BE LATE 2ND PERIOD INTO
THE 3RD PERIOD. THE DAYCREW CAN ASSESS THIS FURTHER W/LATER MODEL
RUNS. THE HWO WILL ADDRESS THIS POTENTIAL.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
THE OCCLUDED FRONT MOVES EAST EARLY MONDAY MORNING WITH STEADY
PRECIPITATION ENDING EARLY. EXPECT MAX TEMPERATURES TO OCCUR EARLY
IN THE DAY BEFORE FALLING A FEW DEGREES DURING THE AFTERNOON AS
SLIGHTLY COOLER FILTERS IN BEHIND THE OCCLUSION. ONCE THE STEADY
PRECIPITATION ENDS MONDAY MORNING IT WILL REMAIN MOSTLY CLOUDY. AN
ARCTIC COLD FRONT WILL APPROACH LATER MONDAY AFTERNOON AND THEN
SWEEP EAST ACROSS THE FA MONDAY NIGHT. THERE WILL BE THE CHANCE
FOR SNOW SHOWERS ACROSS NORTHERN PORTIONS OF THE FA WITH THE
PASSAGE OF THE ARCTIC BOUNDARY...HOWEVER THE BIG STORY WILL BE
THE STRONG COLD ADVECTION LATER MONDAY NIGHT AND TUESDAY.
TEMPERATURES WILL FALL TO ZERO TO 5 ABOVE ZERO ACROSS MUCH OF
NORTHERN MAINE AND LOW TO MID TEENS ACROSS MOST OF DOWNEAST MAINE
BY EARLY TUESDAY MORNING. TEMPERATURES ON TUESDAY WILL NOT RECOVER
MUCH FROM THE EARLY MORNING LOWS WITH HIGHS ONLY EXPECTED TO BE IN
THE SINGLE DIGITS ABOVE ZERO TO AROUND 10 ABOVE NORTH AND 15 TO 20
DOWNEAST. ALONG WITH THE COLD TEMPERATURES WILL COME THE CHANCE
FOR SOME SNOW SHOWERS OR FLURRIES ACROSS THE NORTH WITH PARTLY
CLOUDY SKIES DOWNEAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
IT STILL LOOKS RELATIVELY QUIET THROUGH THE LONG TERM WITH NO BIG
STORMS IN SIGHT. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH
MUCH OF THE PERIOD. BRISK NORTHWEST FLOW WILL CONTINUE TUESDAY
NIGHT AND WEDNESDAY WITH MAINLY DRY CONDITIONS AS HIGH PRESSURE
MOVES EAST. A WEAK DISTURBANCE WILL CROSS THE REGION THURSDAY
FOLLOWED BY HIGH PRESSURE THURSDAY NIGHT. A CLIPPER TYPE SYSTEM
COULD BRING SOME SNOW SHOWERS TO THE REGION BY THE END OF THE
PERIOD.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: IFR/MVFR CONDITIONS WILL GO TO VFR LATER THIS MORNING
W/THE NORTHERN TERMINALS HANGING ONTO MVFR CIGS A WHILE LONGER
W/THE INVERSION. VFR THIS EVENING DROPPING BACK TO MVFR LATER
TONIGHT ACROSS THE NORTHERN TERMINALS W/IFR CONDITIONS FOR BGR AND
BHB NEAR OR AFTER 06Z.
SHORT TERM: MVFR CONDITIONS POSSIBLE IN ANY SCATTERED SNOW SHOWERS
MAINLY ACROSS NORTHERN SECTIONS MONDAY AND TUESDAY OTHERWISE
MAINLY VFR.
&&
.MARINE...
NEAR TERM: DECIDED TO GO TO A GALE WARNING STARTING AFTER 06Z AND
CONTINUING INTO MONDAY AS LLVL JET OF 45-50KT HITS THE WATERS.
GUSTS TO HIT 35KTS. WINDS WILL BE TOUGH TO MIX DOWN W/WAA INITIALLY
AND THEN AS THE OCCLUSION MOVES THROUGH SW WINDS WILL HAVE A CHC
TO MIX DOWN AS LLVLS BEGIN TO COOL. DAYCREW/S WAVE HEIGHTS WERE
MATCHING CLOSE THE LATEST SWAN AND WNAWAVE AND DECIDED TO STAY
CLOSE THE CURRENT FCST OF SEAS BUILDING TO 3-6 FT.
SHORT TERM: GALE FORCE CONDITIONS MONDAY INTO MONDAY NIGHT THEN
SCA CONDITIONS ARE EXPECTED TUESDAY INTO WEDNESDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...GALE WARNING FROM 3 AM TO 7 PM EST MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
913 AM EST SUN JAN 1 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD BRIEFLY ACROSS THE REGION TODAY. AN OCCLUDED
FRONT WILL APPROACH FROM THE WEST THIS EVENING AND CROSS THE
REGION EARLY MONDAY MORNING...FOLLOWED BY A STRONG ARCTIC FRONT
LATE MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...NO MAJOR CHANGES NEEDED FOR THIS UPDATE. HAVE ADJUSTED
SKY COVER A BIT FOR CURRENT CONDITIONS BUT NO OTHER CHANGES
NEEDED.
PREVIOUS DISCUSSION...CLOUDS HANGING ON ACROSS MUCH OF THE CWA
THIS MORNING AS EVIDENT FROM THE LATEST IR SATL IMAGERY. MOISTURE
HANGING ON BELOW 925MBS W/AIRMASS DRY ABOVE THIS LAYER. INVERSION
IS IN PLACE AND IS SHOWN TO HANG ON FOR A WHILE THIS MORNING PER
THE LATEST RUC SOUNDINGS WHICH IS SUPPORT BY THE 00Z NAM. A W FLOW
TAKES OVER LATER THIS MORNING HELPING TO ERODE CLOUDS ACROSS THE
CENTRAL AND DOWNEAST REGION. ACROSS THE NORTH AND WEST, CLOUDS
COULD HANG ON LONGER W/INVERSION HANGING AS SHOWN BY THE SOUNDINGS
SHOWING MOISTURE STAYING TRAPPED AT AROUND 900MBS. DECIDED TO HANG
ON TO SOME CLOUDS LONGER ACROSS THE NORTHERN AND WESTERN AREAS
INTO EARLY AFTERNOON W/MORE SUN ACROSS THE CENTRAL AND DOWNEAST
AREAS. OBVIOUSLY THIS WILL PLAY INTO THE MAX TEMPERATURE FCST
TODAY. ADJUSTED THE DAYCREW/S MAXES FOR TODAY UPWARD ACROSS THE
CWA W/UPPER 20S TO LOWER 30S ACROSS THE NORTH AND WEST AND UPPER
30S TO LOWER 40S FOR CENTRAL AND DOWNEAST AREAS.
TONIGHT COULD BE INTERESTING AS AN OCCLUDED FRONT APCHS FROM THE W
LATER TONIGHT W/PRECIP MOVING IN LATER TONIGHT. LATEST MDL
SOUNDINGS SHOW TEMPERATURES TO BE WARM ENOUGH ACROSS THE CENTRAL
AND DOWNEAST AREAS FOR MAINLY RAIN. ACROSS THE NORTHERN AND
WESTERN AREAS, THINGS LOOK TO BE DIFFERENT AS TEMPERATURES COOL
OFF EARLY TONIGHT AND THEN LEVEL OFF BEFORE RISING WELL AFTER
MIDNIGHT. WX ELEMENT IN THESE AREAS WILL BE IN THE FORM OF SOME
SNOW BUT A TRANSITION TO FREEZING PRECIP IS POSSIBLE. THE NAM AND GFS
BOTH SHOW A WARM LAYER SETTING UP AGAIN FROM 925-850MBS W/A COLD
LAYER AT THE SFC. THIS WILL SET THE STAGE FOR ANOTHER FRZA EVENT.
THE TIMING LOOKS TO BE BRIEF W/FZRA/FZDZ. THERE ALSO LOOKS TO BE A
PERIOD OF SLEET POSSIBLE. BEST SNOW ACCUMULATION WILL BE ACROSS
THE FAR NORTH AND WEST MAINLY NORTH AND WEST OF CAR,PQI & HUL. THE
PRECIP FROM THICKNESS TOOL WAS USED FOR THE WX ELEMENT. QPF IS A
BLEND OF HPC/GFS AND THE NAM WHICH SHOWS THE HIGHEST AREAS ACROSS
DOWNEAST AND AND EASTERN SECTIONS. ADDED SOME ICE ACCUMULATION
MAINLY FOR THE NORTH AND WEST W/<.10". DECIDED TO HOLD OFF ON ANY
WINTER WEATHER ADVISORIES AS THIS LOOKS TO BE LATE 2ND PERIOD INTO
THE 3RD PERIOD. THE DAYCREW CAN ASSESS THIS FURTHER W/LATER MODEL
RUNS. THE HWO WILL ADDRESS THIS POTENTIAL.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
THE OCCLUDED FRONT MOVES EAST EARLY MONDAY MORNING WITH STEADY
PRECIPITATION ENDING EARLY. EXPECT MAX TEMPERATURES TO OCCUR EARLY
IN THE DAY BEFORE FALLING A FEW DEGREES DURING THE AFTERNOON AS
SLIGHTLY COOLER FILTERS IN BEHIND THE OCCLUSION. ONCE THE STEADY
PRECIPITATION ENDS MONDAY MORNING IT WILL REMAIN MOSTLY CLOUDY. AN
ARCTIC COLD FRONT WILL APPROACH LATER MONDAY AFTERNOON AND THEN
SWEEP EAST ACROSS THE FA MONDAY NIGHT. THERE WILL BE THE CHANCE
FOR SNOW SHOWERS ACROSS NORTHERN PORTIONS OF THE FA WITH THE
PASSAGE OF THE ARCTIC BOUNDARY...HOWEVER THE BIG STORY WILL BE
THE STRONG COLD ADVECTION LATER MONDAY NIGHT AND TUESDAY.
TEMPERATURES WILL FALL TO ZERO TO 5 ABOVE ZERO ACROSS MUCH OF
NORTHERN MAINE AND LOW TO MID TEENS ACROSS MOST OF DOWNEAST MAINE
BY EARLY TUESDAY MORNING. TEMPERATURES ON TUESDAY WILL NOT RECOVER
MUCH FROM THE EARLY MORNING LOWS WITH HIGHS ONLY EXPECTED TO BE IN
THE SINGLE DIGITS ABOVE ZERO TO AROUND 10 ABOVE NORTH AND 15 TO 20
DOWNEAST. ALONG WITH THE COLD TEMPERATURES WILL COME THE CHANCE
FOR SOME SNOW SHOWERS OR FLURRIES ACROSS THE NORTH WITH PARTLY
CLOUDY SKIES DOWNEAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
IT STILL LOOKS RELATIVELY QUIET THROUGH THE LONG TERM WITH NO BIG
STORMS IN SIGHT. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH
MUCH OF THE PERIOD. BRISK NORTHWEST FLOW WILL CONTINUE TUESDAY
NIGHT AND WEDNESDAY WITH MAINLY DRY CONDITIONS AS HIGH PRESSURE
MOVES EAST. A WEAK DISTURBANCE WILL CROSS THE REGION THURSDAY
FOLLOWED BY HIGH PRESSURE THURSDAY NIGHT. A CLIPPER TYPE SYSTEM
COULD BRING SOME SNOW SHOWERS TO THE REGION BY THE END OF THE
PERIOD.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: IFR/MVFR CONDITIONS WILL GO TO VFR LATER THIS MORNING
W/THE NORTHERN TERMINALS HANGING ONTO MVFR CIGS A WHILE LONGER
W/THE INVERSION. VFR THIS EVENING DROPPING BACK TO MVFR LATER
TONIGHT ACROSS THE NORTHERN TERMINALS W/IFR CONDITIONS FOR BGR AND
BHB NEAR OR AFTER 06Z.
SHORT TERM: MVFR CONDITIONS POSSIBLE IN ANY SCATTERED SNOW SHOWERS
MAINLY ACROSS NORTHERN SECTIONS MONDAY AND TUESDAY OTHERWISE
MAINLY VFR.
&&
.MARINE...
NEAR TERM: DECIDED TO GO TO A GALE WARNING STARTING AFTER 06Z AND
CONTINUING INTO MONDAY AS LLVL JET OF 45-50KT HITS THE WATERS.
GUSTS TO HIT 35KTS. WINDS WILL BE TOUGH TO MIX DOWN W/WAA INITIALLY
AND THEN AS THE OCCLUSION MOVES THROUGH SW WINDS WILL HAVE A CHC
TO MIX DOWN AS LLVLS BEGIN TO COOL. DAYCREW/S WAVE HEIGHTS WERE
MATCHING CLOSE THE LATEST SWAN AND WNAWAVE AND DECIDED TO STAY
CLOSE THE CURRENT FCST OF SEAS BUILDING TO 3-6 FT.
SHORT TERM: GALE FORCE CONDITIONS MONDAY INTO MONDAY NIGHT THEN
SCA CONDITIONS ARE EXPECTED TUESDAY INTO WEDNESDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...GALE WARNING FROM 3 AM TO 7 PM EST MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HASTINGS/HEWITT
MARINE...HASTINGS/HEWITT/DUDA
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
610 PM EST MON JAN 2 2012
.SYNOPSIS...
COLD NORTHWEST WINDS ACROSS THE GREAT LAKES WILL BRING SNOW
SHOWERS THROUGH TUESDAY ALONG WITH LOW WIND CHILLS.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LATEST UPDATE. AFTER EXAMINING RECENT MODEL RUNS, PARTICULARLY THE
LATEST HRRR AND HIRES NMM-WRF, THERE ARE STRONG INDICATIONS THE A
STRONGER SNOW BAND WILL BEGIN TO SET UP LATER TONIGHT. THIS SEEMS
REASONABLE AND HAVE SEEN THIS IN THE PAST. AS WINDS AT ALL LEVELS
BECOME NORTHWEST, BEHIND THE UL TROUGH, CONDITIONS WILL BE OPTIMAL
FOR A STRONGER AND LARGER LES BAND TO FORM. ADDITIONALLY, THIS
WIND DIRECTION WILL ALSO ALLOW FOR A LAKE HURON INFLUENCE. IN
LATEST UPDATE, WILL ATTEMPT TO PINPOINT WHERE BAND WILL LIKELY
FORM AND ALSO INCREASE THE SNOW AMOUNTS UNDER THE BAND. WILL
EXPAND THE CURRENT ADVISORY SOUTHWARD TO INCLUDE ALLEGHENY,
BEAVER, COLUMBIANA AND HANCOCK COUNTIES AND THE LOW LANDS OF
WESTMO AND FAYETTE. THE WAY THESE BANDS HAVE WORKED IN THE PAST,
THE HIGHEST SNOW AMOUNTS WILL NOT COVER THE WHOLE COUNTY, BUT WILL
BE LIMITED TO LOCATIONS WHICH FALL UNDER THE BAND.
UPPER LEVEL TROUGH AXIS WILL SWING THROUGH THE UPPER OHIO VALLEY
EARLY TONIGHT. FLOW WILL GRADUALLY BECOME MORE NORTHWEST BY EARLY
TONIGHT WITH UPSLOPE FLOW PERSISTING THROUGH TUESDAY. 850MB
TEMPERATURES WILL CHILL TO AROUND -18C OVER NORTHWEST PA BY 12Z
TUESDAY...WITH THE -20C ISOTHERM SLIDING ACROSS THE FORECAST AREA
DURING THE DAY. SNOW SHOWERS WILL CONTINUE INTO EARLY TUESDAY
AFTERNOON WITH HEAVIEST ACCUMULATIONS INITIALLY ALONG THE I-80
CORRIDOR SHIFTING MORE TO THE RIDGES AND WV/MD MOUNTAINS OVERNIGHT
AND TUESDAY MORNING. ADDITIONAL FETCH ACROSS LAKE HURON WILL HELP
TO SET UP A FEW ENHANCED SNOW BANDS WEST OF THE RIDGES AS WELL.
WIND GUSTS TO 30 MPH WILL CAUSE SOME BLOWING AND DRIFTING SNOW.
WITH SUSTAINED WINDS OF AROUND 15 MPH WIND CHILLS TONIGHT WILL FALL
BELOW ZERO IN THE RIDGES BUT BELIEVE READINGS WILL STAY ABOVE -10
THRESHOLD. SO NO WIND CHILL ADVISORY PLANNED. WIND CHILLS ELSEWHERE
IN THE SINGLE DIGITS TONIGHT.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
SNOW SHOWER COVERAGE AND INTENSITY SHOULD DIMINISH BY LATE TUESDAY
AS SURFACE RIDGE BEGINS TO WORK INTO REGION AND INVERSION LOWERS.
WIND CHILLS TUESDAY NIGHT WILL HOVER IN THE SINGLE DIGITS WEST OF
THE RIDGES WITH READINGS IN THE HIGHER ELEVATIONS BETWEEN -5 AND -10.
LATER SHIFTS SHOULD REVIEW NEED FOR ANY WIND CHILL ADVISORIES.
ON WEDNESDAY AND WEDNESDAY NIGHT...A SHORTWAVE TROUGH WILL
QUICKLY SWING SOUTHEAST ACROSS THE UPPER OH VALLEY BRINGING LOW
CHANCES FOR SNOW SHOWERS AS BEST DYNAMICS AND MOISTURE REMAIN
NORTH OF REGION. THURSDAY SHOULD BE MAINLY DRY AS A WEAK RIDGE
MOVES OVER THE REGION. TEMPERATURES WILL RECOVER WELL INTO THE 30S
TO NEAR 40 THURSDAY AFTERNOON.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LATEST MODELS SHOW CLIPPER MOVING ACROSS THE GREAT LAKES THURSDAY
NIGHT AND FRIDAY REMAINING FARTHER NORTH THAN PREVIOUS RUNS...SO
HAVE GONE WITH A DRY FORECAST. WEAK FRONT WILL ARRIVE FRIDAY
NIGHT...WITH BEST CHANCE OF SHOWERS ON SATURDAY. SOME MODEL
DISAGREEMENT FOR SUNDAY INTO MONDAY...WITH DETERMINISTIC MODELS
INDICATING A CYCLONE DEVELOPING ACROSS THE SOUTHEASTERN UNITED
STATES (AND CLIPPING OUR SOUTHERN COUNTIES)...WHILE ENSEMBLES
GENERALLY KEEP CONDITIONS DRY. WITH MODELS STILL SHOWING SOME
INDICATION OF PRECIP...HAVE DECIDED TO KEEP SLIGHT CHANCE POPS FOR
THE SOUTHERN COUNTIES. HAVE ALSO ADDED SOME POPS NORTH FOR LAKE
EFFECT. TEMPERATURES SHOULD BE ABOVE NORMAL FRIDAY AND
SATURDAY...THEN MODERATING FOR SUNDAY AND MONDAY.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
NOW SHOWERS WILL CONTINUE THROUGHOUT THE TAF PERIOD...ALTHOUGH SOME
IMPROVEMENT IS INDICATED LATE TMRRW. IN GENERAL...MVFR STRATCU WL
BE DETERIORATED TO IFR IN THE SHSN AND TAFS WL FEATURE TEMPO
MENTIONS OF THAT POTENTIAL THIS EVE. PROB30 GROUPS WERE ALSO
INCLUDED FOR THE NR DAWN PD AS MDLS ARE IN AGREEMENT IN PROGS OF
BAND FORMATION IN THE DEEPENING NW FLOW BEHIND MID LVL TROUGH THAT
IS CROSSING THE UPR OH VALLEY THIS EVE.
SFC WND WL ALSO RMN AN ISSUE AS DIRECTION BACKED TO THE W/SW THIS
AFTN IN ADVN OF TROUGH. THAT WND WL VEER QUICKLY TO THE NW WITH
PASSAGE OF THAT FEATURE THIS EVE AND GUSTS OF 20 TO 25 KT CAN ALSO
BE EXPECTED.
OUTLOOK...TUESDAY THROUGH SATURDAY...
IMPROVEMENT TO VFR IS EXPECTED TUESDAY NIGHT AS WIND BACKS TO THE SW
WITH BUILDING HIGH PRESSURE. ANOTHER LOW MOVING ACROSS THE GREAT
LAKES COULD BRING SOME RESTRICTIONS IN SNOW SHOWERS WEDNESDAY...BUT
PRIMARILY NORTH OF PITTSBURGH. VFR CONDITIONS ARE THEN EXPECTED AT
ALL SITES THURSDAY THROUGH FRIDAY NIGHT. A FRONT COULD BRING SOME
SCATTERED RESTRICTIONS IN SHOWERS ON SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING UNTIL 4 PM EST TUESDAY FOR MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 4 PM EST TUESDAY FOR OHZ041.
PA...WINTER WEATHER ADVISORY UNTIL 4 PM EST TUESDAY FOR PAZ013>016-
020>023-073-075.
LAKE EFFECT SNOW WARNING UNTIL 4 PM EST TUESDAY FOR PAZ007>009.
WINTER STORM WARNING UNTIL 4 PM EST TUESDAY FOR PAZ074-076.
WV...WINTER WEATHER ADVISORY UNTIL 4 PM EST TUESDAY FOR WVZ001.
WINTER STORM WARNING UNTIL 4 PM EST TUESDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1109 AM EST SUN JAN 1 2012
.SYNOPSIS...
AN INTENSIFYING LOW PRESSURE SYSTEM WILL PUSH INTO THE GREAT LAKES
THIS AFTERNOON, BRINGING A STRONG COLD FRONT AND GUSTY WINDS ACROSS
THE UPPER OHIO VALLEY. THE COLDEST AIR OF THE SEASON WILL PUSH IN
BEHIND THE FRONT WITH SNOW SHOWERS EXPECTED TONIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE INCLUDES MINOR ADJUSTMENTS TO TEMPERATURES...AS WELL AS TIMING
OF PRECIPITATION AND CLOUD COVER OVER EASTERN SECTIONS BASED ON
RADAR/SATELLITE TRENDS. PREVIOUS DISCUSSION FOLLOWS.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH AXIS
EXTENDING FROM THE UPPER MIDWEST INTO THE MISSOURI VALLEY. AHEAD OF
THIS FEATURE, A WEAK RIDGE IS SHIFTING EAST OF THE UPPER OHIO
VALLEY. A DEEP LAYER OF DRY AIR IS IN PLACE, WITH STRATOCUMULUS
ASSOCIATED WITH A 1000-900MB LAYER MOISTURE PUSHING NORTHEAST OF
THE AREA. AT THE SURFACE, AS 1000MB LOW IS CENTERED ACROSS
NORTHERN ILLINOIS. WITH A 1021MB SURFACE HIGH CENTERED OFF THE
CAROLINA COAST, THE PRESSURE GRADIENT IS TIGHTENING ACROSS THE
OHIO VALLEY. IN ADDITION, A COLD FRONT EXTENDS SOUTHWARD OF THE
LOW ACROSS THE MISSOURI VALLEY.
TODAY...THE TROUGH WILL DIG INTO THE OHIO VALLEY AND THE SURFACE LOW
WILL MOVE NORTHEASTWARD ACROSS THE LP OF MICHIGAN, SWINGING THE
FRONT ACROSS THE UPPER OHIO VALLEY AND TIGHTENING THE PRESSURE
GRADIENT ACROSS THE AREA. THE FRONT WILL MOSTLY BE DRY WITH ITS
PASSAGE, ALTHOUGH WITH A TIGHT THERMAL GRADIENT AND HIRES MODELS
INDICATING SUFFICIENT FORCING, CHANCE POPS ARE FORECAST WITH ITS
PASSAGE.
THE MAIN WEATHER IMPACT TODAY WILL BE GUSTY WINDS WITH THE
FRONTAL PASSAGE AND DIURNAL MIXING IN CAA IN THE WAKE OF THE FRONT.
NAM/WRF-NMM SOLUTIONS SUPPORT SUSTAINED WINDS OF 20-25KTS WITH GUSTS
OF 35-40KTS AND THE ONGOING WIND ADVISORY. EXPECT THE GUSTS TO PICK
UP LATE THIS MORNING ACROSS EASTERN OHIO AND ACROSS THE REST OF THE
AREA BY EARLY AFTERNOON. FOR TEMPS, HIGHS WILL BE REACHED MOSTLY BY
18Z, AS CAA KICKS IN. TEMPS ARE A MAV/MET BLEND, RANGING FROM NEAR
50 ACROSS NORTHERN WV AND SOUTHWEST PA TO THE MID 40S FOR AREAS
NORTHWEST OF PITTSBURGH AND ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THERE IS NAM/GFS AGREEMENT THAT THE MID-LEVEL TROUGH WILL DEEPEN AND
BECOME MORE AMPLIFIED AS IT MOVES ACROSS THE OHIO VALLEY TO THE EAST
COAST SUNDAY NIGHT THROUGH TUESDAY.
SUNDAY NIGHT...THE MID-LEVEL TROUGH WILL INSTIGATE SHOWERS ACROSS
THE AREA WITH LOW-LEVEL THICKNESSES QUICKLY DECREASING AND TURNING
PRECIPITATION OVER TO ALL SNOW SHOWERS. THE SURFACE LOW WILL PUSH
NORTHEAST INTO ONTARIO WITH GUSTS WEAKENING WITH THE DECREASE OF
MIXING WITH THE LOSS OF DIURNAL HEATING. WITH A TIGHTENED PRESSURE
GRADIENT, WINDS WILL STILL GUST AT 20-30KTS OVERNIGHT. FOR LOWS,
ONGOING CAA WILL BE IN PLACE, ALTHOUGH CLOUD COVERAGE WILL SERVE TO
COUNTER COLDER AIR ALOFT. LOWS WILL RANGE FROM THE LOWER 20S ACROSS
THE EASTERN RIDGES TO THE MID 20S ELSEWHERE. A LOW-LEVEL FLOW OUT OF
290 DEGREES WILL LIMIT LAKE EFFECT INITIALLY WITH AN INCH
FORECAST OVERNIGHT FOR THE I-80 CORRIDOR.
MONDAY AND MONDAY NIGHT...850MB FLOW WILL SHIFT TO
WEST-NORTHWESTERLY BY 18Z MONDAY AND TAP INTO A HURON FETCH AS IT
SHIFTS TO NORTHWESTERLY BY 00Z TUESDAY. THIS WILL ALLOW FOR LAKE
EFFECT SNOW SHOWERS AND UPSLOPING EVENT TO BEGIN IN EARNEST. WITH
850MB TEMPS NEAR -13C AND A WARM LAKE ERIE WITH TEMPS NEAR 4C, THE
TEMP DIFFERENTIAL WILL BE SUFFICIENT ALONG WITH A DEEP ISOTHERMAL
PROFILE. THUS, ACCUMULATIONS ARE FORECAST OF 4 TO 8 INCHES WITH BANDING OF
SNOWFALL ACROSS THE LAKE EFFECT ZONES AND UPSLOPING FOR THE
RIDGES. EXPECT 2 TO 4 INCHES SOUTH OF I-80 AND NORTH OF PITTSBURGH
WITH 1 TO 3 INCHES FOR AREAS SOUTH AND WEST OF PITTSBURGH.
TUESDAY...ONGOING LAKE EFFECT SNOW EVENT WILL BEGIN TO WIND DOWN
AS A SURFACE HIGH AND LOW-LEVEL RIDGING BUILD INTO THE UPPER OHIO
VALLEY. A LOWERING SUBSIDENCE INVERSION WILL MOSTLY DIMINISH THE
MORE PERSISTENT ACCUMULATING SNOW SHOWERS FOR THE RIDGES AND I-80
CORRIDOR BY THE AFTERNOON HOURS WITH SNOW SHOWERS COMING TO AN END
ELSEWHERE. THE CORE OF THE COLDEST AIR WILL HAVE BUILT IN, WITH
HIGHS STRUGGLING TO REACH THE LOWER 20S ACROSS MUCH OF THE AREA.
GUSTY WINDS OF 20-25KTS ALONG WILL YIELD WIND CHILLS IN THE
SINGLE DIGITS ACROSS THE LOWLANDS AND BELOW ZERO ACROSS THE HIGHER
ELEVATIONS MONDAY THROUGH TUESDAY.
BY THE END OF THIS EVENT, STORM TOTAL ACCUMULATIONS OF 8 TO 12
INCHES WILL BE POSSIBLE FOR THE RIDGES WITH THE I-80 CORRIDOR
GETTING 6 TO 10 INCHES. THUS, LAKE EFFECT SNOW AND WINTER STORM
WATCHES HAVE BEEN UPGRADED TO WARNINGS. THE NEXT TIER OF COUNTIES
SOUTH OF I-80 AND NORTH OF PITTSBURGH MAY NEED ADVISORIES, HOWEVER
AT THIS TIME, CONFIDENCE IN ACCUMULATIONS REACHING 12-HOUR/24-HOUR
CRITERIA IS TOO LOW THERE. THUS, THE WINTER STORM WATCH FOR
JEFFERSON AND CLARION COUNTIES REMAINS IN EFFECT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THERE IS REASONABLE NAEFS/ECMWF MEAN AGREEMENT THAT HIGH PRESSURE WILL
CROSS THE AREA ON TUESDAY NIGHT, BRINGING A DRY FORECAST AND A
RESPITE FROM SNOW SHOWERS. WITH THE COLDEST AIR OF THE SEASON SET IN
AND RADIATIONAL COOLING POSSIBLE, LOWS TUESDAY NIGHT WILL RANGE FROM
THE SINGLE DIGITS ACROSS THE EASTERN RIDGES TO THE LOWER TEENS
ACROSS THE REMAINDER OF THE AREA.
GFSE/ECMWF BLEND WAS USED FOR THE REMAINDER OF THE PERIOD. A ZONAL
MID-LEVEL FLOW WILL BE IN PLACE FOR WEDNESDAY WITH THE SLIGHT CHANCE
OF SNOW SHOWERS. A SHORT WAVE WILL CROSS THE AREA ON WEDNESDAY NIGHT
INTO THURSDAY BRINGING A BETTER CHANCE OF SNOW SHOWERS. WEAK SURFACE
RIDGING IS PROGGED TO DRY THE FORECAST OUT FOR THURSDAY NIGHT INTO
FRIDAY. A FRONT IS THEN PROGGED TO CROSS THE UPPER OHIO VALLEY FOR
THE EARLY WEEKEND. TEMPS WILL BE PROGRESSIVELY WARMER MID-WEEK INTO
THE WEEKEND, AT AROUND 5 DEGREES BELOW NORMAL ON WEDNESDAY AND
WARMING EACH DAY TO 10 DEGREES ABOVE NORMAL BY FRIDAY AND SATURDAY.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
BKN-OVC SKIES SHOULD PREVAIL IN ADVANCE OF AN APPROACHING COLD
FRONT...WITH SITES BOUNCING BETWEEN MVFR/VFR DUE TO CEILINGS VARYING
BETWEEN 2500 AND 3500 FT. LOW LEVEL WIND SHEAR IS ALSO PRESENT AT
TAF SITES. ALTHOUGH SOME SHOWERS HAVE MOVED THROUGH AHEAD OF THE
COLD FRONT (NEAR THE INDIANA-OHIO BORDER AROUND 11AM)...ADDITIONAL
SHOWERS AND A SHARP RISE IN WINDS CAN BE EXPECTED WHEN THE FRONT
MOVES THROUGH. HAVE CONTINUED TO AMEND TAFS TO TRY AND BETTER
HIGHLIGHT TIMING OF FRONT...WITH WINDS SHIFTING FROM SOUTHERLY TO
WESTERLY AND GUSTS UP TO 40 KTS. EXPECT GENERAL MVFR CIGS BEHIND THE
FRONT. STRONG COLD ADVECTION WILL BRING LIGHT SNOW SHOWERS LATE
AFTERNOON OR EVENING AND CONTINUE INTO THE OVERNIGHT WITH WEST WINDS
REMAINING GUSTY.
OUTLOOK...MONDAY THROUGH THURSDAY
GUSTY WINDS WILL REMAIN MONDAY AND TURN NORTHWEST WITH IFR
RESTRICTIONS POSSIBLE WITH SNOW SHOWERS MONDAY THROUGH TUESDAY
NIGHT. VFR CONDITIONS WILL RETURN WEDNESDAY BEFORE THE NEXT
DISTURBANCE BRINGS THE CHANCE OF SNOW SHOWERS WITH RESTRICTIONS ON
THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR MDZ001.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
MDZ001.
OH...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
PAZ074-076.
LAKE EFFECT SNOW WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY
FOR PAZ007>009.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR PAZ015-016.
WV...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ001>004-012.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR WVZ021>023-041.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1028 AM EST SUN JAN 1 2012
.SYNOPSIS...
A STRONG COLD FRONT IN THE OHIO VALLEY WILL MOVE EAST TODAY AND
CROSS THE REGION LATE THIS AFTERNOON AND THIS EVENING. BEHIND THE
FRONT HIGH PRESSURE WILL BUILD BRINGING GUSTY NORTHWESTERLY WINDS
AND COLDER TEMPERATURES ON MONDAY AND TUESDAY...WITH SOME OF THE
COLDEST READINGS OF THE SEASON EXPECTED TUESDAY NIGHT. HIGH
PRESSURE CROSSES THE REGION ON WEDNESDAY...WITH MODERATING
TEMPERATURES EXPECTED FOR THE LATTER PORTION OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
CLEAR SKIES ATTM ACROSS THE CWA AT 14Z WITH WEAK HIGH PRESSURE
ACROSS THE REGION. VSBL SATL IMAGERY SHOWS EXTENSIVE AREA OF
CLOUDS JUST TO THE WEST HEADING EAST. SOME DISSIPATION OF CLOUD
COVER IS EXPECTED AS THE AREA CROSSES THE MOUNTAINS...BUT HAVE
KEPT SOME CLOUDS IN FOR THIS AFTN.
WATER VAPOR IMAGERY SHOWING INTENSE SHRTWV TROUGH EXTENDING FROM
CNTRL IN INTO THE WRN TN. A DECENT 50 HPA SPEED MAX OF NEARLY 100
KT EXTENDS JUST EAST OF THE TROUGH AXIS. THIS WILL ALLOW DECENT
WAA TO OCCUR THIS AFTERNOON ACROSS THE CWA...WHICH IS REFLECTED
IN UNSEASONABLY WARM TEMPS IN THE GRIDS OF MID 50S TO LWR 60S. 12Z
LWX SOUNDING SUPPORTS AROUND 60F IN DC/BALT METRO REGION THIS AFTN.
HI RES MDL GUIDANCE SHOWING QUITE A SPREAD IN PRECIP CHANCE ACROSS
THE CWA THIS AFTERNOON. THE INITIAL BAND OF REFLECTIVITY THAT WAS
LOCATED ACROSS ERN OH-WRN PA AND CNTRL WV IS BREAKING UP AS IT
MOVES EAST. THE MDLS SEEM TO HAVE A HANDLE ON THAT.
ANOTHER AREA OF PRECIP HAS BROKEN OUT ACROSS CNTRL TN-KY THIS
MORNING. THE 00Z NCEP-HIRES 4KM NMM WRF MODEL ACTUALLY SHOWS THIS
BETTER THAN THE 00Z NCEP-HIRES 4KM ARW WRF...AND LATER RUNS OF
THE 3KM HRRR FROM 11Z SUPPORT THE NMM-WRF SOLN. BOTH THE NCEP 4KM
WRF-NMM AND GSD EXPERIMENTAL 3KM HRRR RUNS SUGGEST SCATTERED COVERAGE
OF SHOWERS ACROSS MAINLY THE NRN PORTION OF THE CWA BETWEEN 18Z
AND 00Z/2ND. THE 4KM WRF-ARW IS DRY THOUGH FOR THIS SAME PERIOD.
OUR LOCAL 4KM WRF NMM AND ARW RUNS ARE SIMILAR TO THE NCEP RUNS.
WITH THE STEEPENED LAPSE RATES EXPECTED LATER THIS AFTERNOON...SOME
SHOWERS COULD PRODUCE GUSTY WINDS OF 30-35 KT AND SMALL HAIL...
SOMETHING THAT WAS REPORTED EARLIER IN INDIANAPOLIS AS THE SYSTEM
MOVED THROUGH THERE. WILL KEEP EYE ON THIS POTENTIAL...SINCE SPCL
MARINE WARNINGS COULD BE NEEDED LATE THIS AFTERNOON/EARLY EVENING.
ATTM...DO NOT THINK THERE IS SUFFICIENT INSTABILITY FOR THUNDER WITH
THIS ACTIVITY.
WILL CONTINUE TO EVALUATE NEED FOR WIND ADVSRY. ATTM...AM NOT
CONFIDENT OF THE AREA...BUT EXPECT SOMETHING MIGHT BE NEEDED FOR
THE WESTERN 5 COUNTIES FOR TONIGHT.
FOR THE WESTERN 5 UPSLOPE COUNTIES...AM STILL THINKING THE TRANSITION
FROM RAIN TO SNOW SHOWER ACTIVITY WILL BE BETWEEN 21Z AND 00Z.
INITIAL SNOW ACCUM TONIGHT WILL DEPEND ON HOW MUCH SNOW CAN FALL
BEFORE DRYING TAKES PLACE. INSTABILITY IS PRETTY INTENSE STARTING
THIS EVENING OUT WEST...SO INTENSE SNOW SHOWER ACTIVITY AFTER 00Z
COULD PRODUCE A QUICK SEVERAL INCHES IN AN HOUR OR SO BEFORE
DRYING WINS OUT. OTHERWISE...HEADLINES REMAIN AS IS FOR NOW.
PREVIOUS DISCUSSIONS FOLLOW.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
ERY WK WX WILL BE DOMINATED BY INTENSE CAA IN STRONG NW FLOW.
MID-ATLC WILL RESIDE BENEATH DEEP UPR TROF AND BTWN LOPRES OVR
CANADIAN MARITIMES AND HIPRES BUILDING IN FROM MS VLY. COOLER...
YET STILL SEASONABLE...TEMPS ARE XPCD MON/MON NGT BEFORE H8 TEMPS
PLUMMET TO AOB -15C TUE...TRANSLATING TO MAXIMA RNGG FROM TEENS AT
HIGHER ELEVATIONS TO M30S CENTRAL FOOTHILLS/PIEDMONT AND SRN MD.
MINIMA TUE NGT SHUD BE COLDEST OF SEASON THUS FAR...TEENS MOST
LOCATIONS.
STEEP LLVL LAPSE RATES/GOOD INSTABILITY...DEEP MOIST LYR...AND
UPSLOPE FLOW SHUD LEAD TO SIGNIFICANT SNOWFALL IN FAVORED AREAS...
AND WSW IN EFFECT THRU TUE WHERE ACCUMS IN EXCESS OF 6IN/12HR AND
8IN/24HR LIKELY. E OF ALLEGHENY FRONT...DOWNSLOPING WILL RESTRICT
PRECIP TO SCATTERED -SNSH ACRS THE POTOMAC HIGHLANDS...WITH ONLY
FLURRIES ACRS SHENANDOAH VLY AND BLUE RIDGE. ELSEWHERE...BKN/OVC
CONDS IN SC. UPSLOPE SN SHUD TAPER OFF LATE TUE AS MOIST LYR
BECOMES QUITE SHALLOW AND WINDS BCM MORE WLY.
GUSTY NW WINDS MON/TUE...AT LEAST 35 KTS ACRS MTNS...WILL CREATE
BLOWING/DRIFTING SN IN WRNG AREA...AND NEAR BLIZZARD CONDS/ZERO VSBY
PSBL. WIND CHILL VALUES ALSO OF CONCERN...XPCD TO DROP TO AS LOW AS
-10F ON HIGHER RIDGES. WIND CHILLS IN TEENS/SOME SINGLE DIGITS/
FCST FOR REMAINDER OF CWA...WITH LOWEST VALUES MON NGT AND ERY
TUE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
SFC RDG PASSES S OF RGN ON WED...WITH CONTD BLW-NRML TEMPS FOR
MID-ATLC. WED NGT/THU...SHRTWV TROF PASSES N OF RGN...PROVIDING
ANOTHER OPPORTUNITY FOR UPSLOPE SNSH...MOSTLY LGT...ACRS WRN
ZONES. ZONAL FLOW ESTABLISHES FOR THU THRU SAT...ALLOWING TEMPS TO
MODERATE AND RISE TO ABV NRML. NEXT SHRTWV TROF/CDFNT POISED TO
IMPACT RGN NEXT WKEND.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
CLEAR SKIES WILL GIVE WAY TO MORE SCT CLOUDS THIS AFTERNOON.
SOUTHERN WINDS INCREASE AS WELL WITH GUSTS IN THE L20 KT RANGE
STARTING 17-18Z ACRS DC/BALT TAF SITES. SCT SHOWER ACTIVITY LATE
THIS AFTERNOON...WITH A FEW SHOWERS CAPABLE OF PRODUCING BRIEF
GUSTS TO 35KT AND BREIF MVFR CIGS.
FOR TONIGHT...AT DCA-BWI-IAD...EXPECT SCT-BKN CIGS 040-060
THROUGH 04Z...THEN SOME CLEARING. BKN040 HANGS MOST OF THE NIGHT
AT MRB. VFR CONDS SHUD PREVAIL MUCH OF THE WEEK. GUSTY NW WINDS...IN
EXCESS OF 30 KTS AT TIMES...FCST FOR MON/TUE...BEFORE HI PRESSURE BUILDS
IN WED...BRINGING LIGHTER WINDS.
&&
.MARINE...
EXPECT GUSTY WINDS TO COMMENCE AROUND NOON TIME FROM THE SOUTH.
WILL CONTINUE SCA.
SHWRS EXPECTED FROM LATE THIS AFTN ESPECIALLY ACROSS THE NORTHERN
THIRD OF THE WATERS. GIVEN DYNAMIC WIND FIELD ALOFT...ANY SHWRS MAY BE
ACCOMPANIED BY GUSTS IN EXCESS OF 34 KT. IF SHWRS FORM AND APRCH
THE WATERS...SPCL MARINE WRNGS MAY BE NEEDED.
ADZY EXTDD FOR WATER THRU MON AS TIGHT PRES GRADIENT WILL SUPPORT 25
KT GUSTS. GUSTS AT LEAST AS INTENSE WILL CONT INTO TUE NGT AND SCA
WILL BE NECESSARY DURG THIS PERIOD. RISK FOR GALES INCR OVNGT MON
AND TUE...AND MAY PERSIST INTO TUE NGT. HIPRES BUILDS IN
WED...LEADING TO DIMINISHED WINDS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WINTER STORM WARNING FROM 1 AM MONDAY TO 5 PM EST TUESDAY FOR
MDZ501.
VA...WINTER STORM WARNING FROM 1 AM MONDAY TO 5 PM EST TUESDAY FOR
VAZ503.
WV...WINTER STORM WARNING FROM 1 AM MONDAY TO 5 PM EST TUESDAY FOR
WVZ501-503-505.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ530>543.
&&
$$
SYNOPSIS...SMZ
NEAR TERM...SMZ
SHORT TERM...MRK
LONG TERM...SBK
AVIATION...CJL/SMZ
MARINE...SMZ/MRK
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
731 AM EST SUN JAN 1 2012
.SYNOPSIS...
AN INTENSIFYING LOW PRESSURE SYSTEM WILL PUSH INTO THE GREAT LAKES
TODAY, BRINGING A STRONG COLD FRONT AND GUSTY WINDS ACROSS THE
UPPER OHIO VALLEY. THE COLDEST AIR OF THE SEASON WILL PUSH IN
BEHIND THE FRONT WITH SNOW SHOWERS EXPECTED TONIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH 730AM UPDATE...MADE SOME MINOR TWEAKS TO CLOUD COVER AND
TIMING OF PRECIPITATION BASED ON RADAR/SATELLITE TRENDS...WHICH
SLIGHTLY SPEEDS UP ARRIVAL OF SHOWERS. OTHERWISE...GOING FORECAST
LOOKS GOOD. PREVIOUS DISCUSSION FOLLOWS.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH AXIS
EXTENDING FROM THE UPPER MIDWEST INTO THE MISSOURI VALLEY. AHEAD OF
THIS FEATURE, A WEAK RIDGE IS SHIFTING EAST OF THE UPPER OHIO
VALLEY. A DEEP LAYER OF DRY AIR IS IN PLACE, WITH STRATOCUMULUS
ASSOCIATED WITH A 1000-900MB LAYER MOISTURE PUSHING NORTHEAST OF
THE AREA. AT THE SURFACE, AS 1000MB LOW IS CENTERED ACROSS
NORTHERN ILLINOIS. WITH A 1021MB SURFACE HIGH CENTERED OFF THE
CAROLINA COAST, THE PRESSURE GRADIENT IS TIGHTENING ACROSS THE
OHIO VALLEY. IN ADDITION, A COLD FRONT EXTENDS SOUTHWARD OF THE
LOW ACROSS THE MISSOURI VALLEY.
TODAY...THE TROUGH WILL DIG INTO THE OHIO VALLEY AND THE SURFACE LOW
WILL MOVE NORTHEASTWARD ACROSS THE LP OF MICHIGAN, SWINGING THE
FRONT ACROSS THE UPPER OHIO VALLEY AND TIGHTENING THE PRESSURE
GRADIENT ACROSS THE AREA. THE FRONT WILL MOSTLY BE DRY WITH ITS
PASSAGE, ALTHOUGH WITH A TIGHT THERMAL GRADIENT AND HIRES MODELS
INDICATING SUFFICIENT FORCING, CHANCE POPS ARE FORECAST WITH ITS
PASSAGE.
THE MAIN WEATHER IMPACT TODAY WILL BE GUSTY WINDS WITH THE
FRONTAL PASSAGE AND DIURNAL MIXING IN CAA IN THE WAKE OF THE FRONT.
NAM/WRF-NMM SOLUTIONS SUPPORT SUSTAINED WINDS OF 20-25KTS WITH GUSTS
OF 35-40KTS AND THE ONGOING WIND ADVISORY. EXPECT THE GUSTS TO PICK
UP LATE THIS MORNING ACROSS EASTERN OHIO AND ACROSS THE REST OF THE
AREA BY EARLY AFTERNOON. FOR TEMPS, HIGHS WILL BE REACHED MOSTLY BY
18Z, AS CAA KICKS IN. TEMPS ARE A MAV/MET BLEND, RANGING FROM NEAR
50 ACROSS NORTHERN WV AND SOUTHWEST PA TO THE MID 40S FOR AREAS
NORTHWEST OF PITTSBURGH AND ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THERE IS NAM/GFS AGREEMENT THAT THE MID-LEVEL TROUGH WILL DEEPEN AND
BECOME MORE AMPLIFIED AS IT MOVES ACROSS THE OHIO VALLEY TO THE EAST
COAST SUNDAY NIGHT THROUGH TUESDAY.
SUNDAY NIGHT...THE MID-LEVEL TROUGH WILL INSTIGATE SHOWERS ACROSS
THE AREA WITH LOW-LEVEL THICKNESSES QUICKLY DECREASING AND TURNING
PRECIPITATION OVER TO ALL SNOW SHOWERS. THE SURFACE LOW WILL PUSH
NORTHEAST INTO ONTARIO WITH GUSTS WEAKENING WITH THE DECREASE OF
MIXING WITH THE LOSS OF DIURNAL HEATING. WITH A TIGHTENED PRESSURE
GRADIENT, WINDS WILL STILL GUST AT 20-30KTS OVERNIGHT. FOR LOWS,
ONGOING CAA WILL BE IN PLACE, ALTHOUGH CLOUD COVERAGE WILL SERVE TO
COUNTER COLDER AIR ALOFT. LOWS WILL RANGE FROM THE LOWER 20S ACROSS
THE EASTERN RIDGES TO THE MID 20S ELSEWHERE. A LOW-LEVEL FLOW OUT OF
290 DEGREES WILL LIMIT LAKE EFFECT INITIALLY WITH AN INCH
FORECAST OVERNIGHT FOR THE I-80 CORRIDOR.
MONDAY AND MONDAY NIGHT...850MB FLOW WILL SHIFT TO
WEST-NORTHWESTERLY BY 18Z MONDAY AND TAP INTO A HURON FETCH AS IT
SHIFTS TO NORTHWESTERLY BY 00Z TUESDAY. THIS WILL ALLOW FOR LAKE
EFFECT SNOW SHOWERS AND UPSLOPING EVENT TO BEGIN IN EARNEST. WITH
850MB TEMPS NEAR -13C AND A WARM LAKE ERIE WITH TEMPS NEAR 4C, THE
TEMP DIFFERENTIAL WILL BE SUFFICIENT ALONG WITH A DEEP ISOTHERMAL
PROFILE. THUS, ACCUMULATIONS ARE FORECAST OF 4 TO 8 INCHES WITH BANDING OF
SNOWFALL ACROSS THE LAKE EFFECT ZONES AND UPSLOPING FOR THE
RIDGES. EXPECT 2 TO 4 INCHES SOUTH OF I-80 AND NORTH OF PITTSBURGH
WITH 1 TO 3 INCHES FOR AREAS SOUTH AND WEST OF PITTSBURGH.
TUESDAY...ONGOING LAKE EFFECT SNOW EVENT WILL BEGIN TO WIND DOWN
AS A SURFACE HIGH AND LOW-LEVEL RIDGING BUILD INTO THE UPPER OHIO
VALLEY. A LOWERING SUBSIDENCE INVERSION WILL MOSTLY DIMINISH THE
MORE PERSISTENT ACCUMULATING SNOW SHOWERS FOR THE RIDGES AND I-80
CORRIDOR BY THE AFTERNOON HOURS WITH SNOW SHOWERS COMING TO AN END
ELSEWHERE. THE CORE OF THE COLDEST AIR WILL HAVE BUILT IN, WITH
HIGHS STRUGGLING TO REACH THE LOWER 20S ACROSS MUCH OF THE AREA.
GUSTY WINDS OF 20-25KTS ALONG WILL YIELD WIND CHILLS IN THE
SINGLE DIGITS ACROSS THE LOWLANDS AND BELOW ZERO ACROSS THE HIGHER
ELEVATIONS MONDAY THROUGH TUESDAY.
BY THE END OF THIS EVENT, STORM TOTAL ACCUMULATIONS OF 8 TO 12
INCHES WILL BE POSSIBLE FOR THE RIDGES WITH THE I-80 CORRIDOR
GETTING 6 TO 10 INCHES. THUS, LAKE EFFECT SNOW AND WINTER STORM
WATCHES HAVE BEEN UPGRADED TO WARNINGS. THE NEXT TIER OF COUNTIES
SOUTH OF I-80 AND NORTH OF PITTSBURGH MAY NEED ADVISORIES, HOWEVER
AT THIS TIME, CONFIDENCE IN ACCUMULATIONS REACHING 12-HOUR/24-HOUR
CRITERIA IS TOO LOW THERE. THUS, THE WINTER STORM WATCH FOR
JEFFERSON AND CLARION COUNTIES REMAINS IN EFFECT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THERE IS REASONABLE NAEFS/ECMWF MEAN AGREEMENT THAT HIGH PRESSURE WILL
CROSS THE AREA ON TUESDAY NIGHT, BRINGING A DRY FORECAST AND A
RESPITE FROM SNOW SHOWERS. WITH THE COLDEST AIR OF THE SEASON SET IN
AND RADIATIONAL COOLING POSSIBLE, LOWS TUESDAY NIGHT WILL RANGE FROM
THE SINGLE DIGITS ACROSS THE EASTERN RIDGES TO THE LOWER TEENS
ACROSS THE REMAINDER OF THE AREA.
GFSE/ECMWF BLEND WAS USED FOR THE REMAINDER OF THE PERIOD. A ZONAL
MID-LEVEL FLOW WILL BE IN PLACE FOR WEDNESDAY WITH THE SLIGHT CHANCE
OF SNOW SHOWERS. A SHORT WAVE WILL CROSS THE AREA ON WEDNESDAY NIGHT
INTO THURSDAY BRINGING A BETTER CHANCE OF SNOW SHOWERS. WEAK SURFACE
RIDGING IS PROGGED TO DRY THE FORECAST OUT FOR THURSDAY NIGHT INTO
FRIDAY. A FRONT IS THEN PROGGED TO CROSS THE UPPER OHIO VALLEY FOR
THE EARLY WEEKEND. TEMPS WILL BE PROGRESSIVELY WARMER MID-WEEK INTO
THE WEEKEND, AT AROUND 5 DEGREES BELOW NORMAL ON WEDNESDAY AND
WARMING EACH DAY TO 10 DEGREES ABOVE NORMAL BY FRIDAY AND SATURDAY.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
SKIES WILL BE CLEAR EARLY THIS MORNING AHEAD OF A STRONG COLD
FRONT APPROACHING FROM THE GREAT LAKES. VFR CIGS WITH SHOWERS
AHEAD OF AND BEHIND THE FRONT. PRESSURE GRADIENT WILL TIGHTEN
SIGNIFICANTLY AHEAD OF THE FRONT WITH WINDS SHIFTING FROM SOUTH TO
SOUTHWEST AND GUSTS OVER 30KTS. AS UPPER LEVEL TROUGH ADVANCES
EAST FROM THE GREAT LAKES THIS AFTERNOON EXPECT GENERAL MVFR CIGS
WITH A FEW LIGHT SHOWERS AND WINDS BECOMING WEST AND GUSTING
30-35KTS. STRONG COLD ADVECTION WILL BRING LIGHT SNOW SHOWERS
LATE AFTERNOON OR EVENING AND CONTINUE INTO THE OVERNIGHT WITH
WEST WINDS REMAINING GUSTY.
OUTLOOK...MONDAY THROUGH THURSDAY
GUSTY WINDS WILL REMAIN MONDAY AND TURN NORTHWEST WITH IFR
RESTRICTIONS POSSIBLE WITH SNOW SHOWERS MONDAY THROUGH TUESDAY
NIGHT. VFR CONDITIONS WILL RETURN WEDNESDAY BEFORE THE NEXT
DISTURBANCE BRINGS THE CHANCE OF SNOW SHOWERS WITH RESTRICTIONS ON
THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR MDZ001.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
MDZ001.
OH...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR PAZ007>009-013>016-020>023-029-031-073>076.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
PAZ074-076.
LAKE EFFECT SNOW WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY
FOR PAZ007>009.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR PAZ015-016.
WV...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ001>004-012.
WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR WVZ021>023-041.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
634 AM EST SUN JAN 1 2012
.SYNOPSIS...
AN INTENSIFYING LOW PRESSURE SYSTEM WILL PUSH INTO THE GREAT LAKES
TODAY, BRINGING A STRONG COLD FRONT AND GUSTY WINDS ACROSS THE
UPPER OHIO VALLEY. THE COLDEST AIR OF THE SEASON WILL PUSH IN
BEHIND THE FRONT WITH SNOW SHOWERS EXPECTED TONIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB TROUGH AXIS
EXTENDING FROM THE UPPER MIDWEST INTO THE MISSOURI VALLEY. AHEAD OF
THIS FEATURE, A WEAK RIDGE IS SHIFTING EAST OF THE UPPER OHIO
VALLEY. A DEEP LAYER OF DRY AIR IS IN PLACE, WITH STRATOCUMULUS
ASSOCIATED WITH A 1000-900MB LAYER MOISTURE PUSHING NORTHEAST OF
THE AREA. AT THE SURFACE, AS 1000MB LOW IS CENTERED ACROSS
NORTHERN ILLINOIS. WITH A 1021MB SURFACE HIGH CENTERED OFF THE
CAROLINA COAST, THE PRESSURE GRADIENT IS TIGHTENING ACROSS THE
OHIO VALLEY. IN ADDITION, A COLD FRONT EXTENDS SOUTHWARD OF THE
LOW ACROSS THE MISSOURI VALLEY.
TODAY...THE TROUGH WILL DIG INTO THE OHIO VALLEY AND THE SURFACE LOW
WILL MOVE NORTHEASTWARD ACROSS THE LP OF MICHIGAN, SWINGING THE
FRONT ACROSS THE UPPER OHIO VALLEY AND TIGHTENING THE PRESSURE
GRADIENT ACROSS THE AREA. THE FRONT WILL MOSTLY BE DRY WITH ITS
PASSAGE, ALTHOUGH WITH A TIGHT THERMAL GRADIENT AND HIRES MODELS
INDICATING SUFFICIENT FORCING, CHANCE POPS ARE FORECAST WITH ITS
PASSAGE.
THE MAIN WEATHER IMPACT TODAY WILL BE GUSTY WINDS WITH THE
FRONTAL PASSAGE AND DIURNAL MIXING IN CAA IN THE WAKE OF THE FRONT.
NAM/WRF-NMM SOLUTIONS SUPPORT SUSTAINED WINDS OF 20-25KTS WITH GUSTS
OF 35-40KTS AND THE ONGOING WIND ADVISORY. EXPECT THE GUSTS TO PICK
UP LATE THIS MORNING ACROSS EASTERN OHIO AND ACROSS THE REST OF THE
AREA BY EARLY AFTERNOON. FOR TEMPS, HIGHS WILL BE REACHED MOSTLY BY
18Z, AS CAA KICKS IN. TEMPS ARE A MAV/MET BLEND, RANGING FROM NEAR
50 ACROSS NORTHERN WV AND SOUTHWEST PA TO THE MID 40S FOR AREAS
NORTHWEST OF PITTSBURGH AND ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THERE IS NAM/GFS AGREEMENT THAT THE MID-LEVEL TROUGH WILL DEEPEN AND
BECOME MORE AMPLIFIED AS IT MOVES ACROSS THE OHIO VALLEY TO THE EAST
COAST SUNDAY NIGHT THROUGH TUESDAY.
SUNDAY NIGHT...THE MID-LEVEL TROUGH WILL INSTIGATE SHOWERS ACROSS
THE AREA WITH LOW-LEVEL THICKNESSES QUICKLY DECREASING AND TURNING
PRECIPITATION OVER TO ALL SNOW SHOWERS. THE SURFACE LOW WILL PUSH
NORTHEAST INTO ONTARIO WITH GUSTS WEAKENING WITH THE DECREASE OF
MIXING WITH THE LOSS OF DIURNAL HEATING. WITH A TIGHTENED PRESSURE
GRADIENT, WINDS WILL STILL GUST AT 20-30KTS OVERNIGHT. FOR LOWS,
ONGOING CAA WILL BE IN PLACE, ALTHOUGH CLOUD COVERAGE WILL SERVE TO
COUNTER COLDER AIR ALOFT. LOWS WILL RANGE FROM THE LOWER 20S ACROSS
THE EASTERN RIDGES TO THE MID 20S ELSEWHERE. A LOW-LEVEL FLOW OUT OF
290 DEGREES WILL LIMIT LAKE EFFECT INITIALLY WITH AN INCH
FORECAST OVERNIGHT FOR THE I-80 CORRIDOR.
MONDAY AND MONDAY NIGHT...850MB FLOW WILL SHIFT TO
WEST-NORTHWESTERLY BY 18Z MONDAY AND TAP INTO A HURON FETCH AS IT
SHIFTS TO NORTHWESTERLY BY 00Z TUESDAY. THIS WILL ALLOW FOR LAKE
EFFECT SNOW SHOWERS AND UPSLOPING EVENT TO BEGIN IN EARNEST. WITH
850MB TEMPS NEAR -13C AND A WARM LAKE ERIE WITH TEMPS NEAR 4C, THE
TEMP DIFFERENTIAL WILL BE SUFFICIENT ALONG WITH A DEEP ISOTHERMAL
PROFILE. THUS, ACCUMULATIONS ARE FORECAST OF 4 TO 8 INCHES WITH BANDING OF
SNOWFALL ACROSS THE LAKE EFFECT ZONES AND UPSLOPING FOR THE
RIDGES. EXPECT 2 TO 4 INCHES SOUTH OF I-80 AND NORTH OF PITTSBURGH
WITH 1 TO 3 INCHES FOR AREAS SOUTH AND WEST OF PITTSBURGH.
TUESDAY...ONGOING LAKE EFFECT SNOW EVENT WILL BEGIN TO WIND DOWN
AS A SURFACE HIGH AND LOW-LEVEL RIDGING BUILD INTO THE UPPER OHIO
VALLEY. A LOWERING SUBSIDENCE INVERSION WILL MOSTLY DIMINISH THE
MORE PERSISTENT ACCUMULATING SNOW SHOWERS FOR THE RIDGES AND I-80
CORRIDOR BY THE AFTERNOON HOURS WITH SNOW SHOWERS COMING TO AN END
ELSEWHERE. THE CORE OF THE COLDEST AIR WILL HAVE BUILT IN, WITH
HIGHS STRUGGLING TO REACH THE LOWER 20S ACROSS MUCH OF THE AREA.
GUSTY WINDS OF 20-25KTS ALONG WILL YIELD WIND CHILLS IN THE
SINGLE DIGITS ACROSS THE LOWLANDS AND BELOW ZERO ACROSS THE HIGHER
ELEVATIONS MONDAY THROUGH TUESDAY.
BY THE END OF THIS EVENT, STORM TOTAL ACCUMULATIONS OF 8 TO 12
INCHES WILL BE POSSIBLE FOR THE RIDGES WITH THE I-80 CORRIDOR
GETTING 6 TO 10 INCHES. THUS, LAKE EFFECT SNOW AND WINTER STORM
WATCHES HAVE BEEN UPGRADED TO WARNINGS. THE NEXT TIER OF COUNTIES
SOUTH OF I-80 AND NORTH OF PITTSBURGH MAY NEED ADVISORIES, HOWEVER
AT THIS TIME, CONFIDENCE IN ACCUMULATIONS REACHING 12-HOUR/24-HOUR
CRITERIA IS TOO LOW THERE. THUS, THE WINTER STORM WATCH FOR
JEFFERSON AND CLARION COUNTIES REMAINS IN EFFECT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THERE IS REASONABLE NAEFS/ECMWF MEAN AGREEMENT THAT HIGH PRESSURE WILL
CROSS THE AREA ON TUESDAY NIGHT, BRINGING A DRY FORECAST AND A
RESPITE FROM SNOW SHOWERS. WITH THE COLDEST AIR OF THE SEASON SET IN
AND RADIATIONAL COOLING POSSIBLE, LOWS TUESDAY NIGHT WILL RANGE FROM
THE SINGLE DIGITS ACROSS THE EASTERN RIDGES TO THE LOWER TEENS
ACROSS THE REMAINDER OF THE AREA.
GFSE/ECMWF BLEND WAS USED FOR THE REMAINDER OF THE PERIOD. A ZONAL
MID-LEVEL FLOW WILL BE IN PLACE FOR WEDNESDAY WITH THE SLIGHT CHANCE
OF SNOW SHOWERS. A SHORT WAVE WILL CROSS THE AREA ON WEDNESDAY NIGHT
INTO THURSDAY BRINGING A BETTER CHANCE OF SNOW SHOWERS. WEAK SURFACE
RIDGING IS PROGGED TO DRY THE FORECAST OUT FOR THURSDAY NIGHT INTO
FRIDAY. A FRONT IS THEN PROGGED TO CROSS THE UPPER OHIO VALLEY FOR
THE EARLY WEEKEND. TEMPS WILL BE PROGRESSIVELY WARMER MID-WEEK INTO
THE WEEKEND, AT AROUND 5 DEGREES BELOW NORMAL ON WEDNESDAY AND
WARMING EACH DAY TO 10 DEGREES ABOVE NORMAL BY FRIDAY AND SATURDAY.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SKIES WILL BE CLEAR EARLY THIS MORNING AHEAD OF A STRONG COLD
FRONT APPROACHING FROM THE GREAT LAKES. VFR CIGS WITH SHOWERS
AHEAD OF AND BEHIND THE FRONT. PRESSURE GRADIENT WILL TIGHTEN
SIGNIFICANTLY AHEAD OF THE FRONT WITH WINDS SHIFTING FROM SOUTH TO
SOUTHWEST AND GUSTS OVER 30KTS. AS UPPER LEVEL TROUGH ADVANCES
EAST FROM THE GREAT LAKES THIS AFTERNOON EXPECT GENERAL MVFR CIGS
WITH A FEW LIGHT SHOWERS AND WINDS BECOMING WEST AND GUSTING
30-35KTS. STRONG COLD ADVECTION WILL BRING LIGHT SNOW SHOWERS
LATE AFTERNOON OR EVENING AND CONTINUE INTO THE OVERNIGHT WITH
WEST WINDS REMAINING GUSTY.
OUTLOOK...MONDAY THROUGH THURSDAY
GUSTY WINDS WILL REMAIN MONDAY AND TURN NORTHWEST WITH IFR
RESTRICTIONS POSSIBLE WITH SNOW SHOWERS MONDAY THROUGH TUESDAY
NIGHT. VFR CONDITIONS WILL RETURN WEDNESDAY BEFORE THE NEXT
DISTURBANCE BRINGS THE CHANCE OF SNOW SHOWERS WITH RESTRICTIONS ON
THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR MDZ001.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
MDZ001.
OH...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR PAZ007>009-013>016-020>023-029-031-073>076.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
PAZ074-076.
LAKE EFFECT SNOW WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY
FOR PAZ007>009.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR PAZ015-016.
WV...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ001>004-012.
WIND ADVISORY FROM 11 AM THIS MORNING TO 10 PM EST THIS
EVENING FOR WVZ021>023-041.
WINTER STORM WARNING FROM 1 AM MONDAY TO 4 PM EST TUESDAY FOR
WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
1212 PM CST SUN JAN 1 2012
.AVIATION...18Z ISSUANCE...
WIDESPREAD MVFR/VFR CEILINGS AND VSBYS WITH STRONG NORTHWEST
WINDS GUSTING AROUND 30 KNOTS WILL PREVAIL THROUGH 04Z. A FEW
GUSTS TO 40 KTS WILL BE POSSIBLE THROUGH 02Z...MAINLY NEAR KBRD
AND KDLH. BRIEF PERIODS OF LIFR VSBYS WILL BE FOUND IN HEAVIER SNOW
SHOWERS DUE TO BLSN. CONDITIONS WILL IMPROVE EARLY MONDAY MORNING
AS WINDS DIMINISH AND SKIES SCATTER FROM THE WEST. THE EXCEPTION
WILL BE OVER WISCONSIN AREAS AND THE KHYR TERMINAL WHERE
ADDITIONAL LAKE EFFECT SNOW SHOWERS AND CLOUDS WILL LINGER THROUGH
MONDAY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 947 AM CST SUN JAN 1 2012/
UPDATE...INCREASE POPS ACROSS MN ZONES THIS MORNING AS AREA OF
ENHANCED MOISTURE WITHIN 85/70H LATER ADVECTS SOUTHEASTWARD.
LATEST RUC13 ANALYSIS SHOWS -35C/50H COLD POOL IS MOVING ACROSS
CWA THIS MORNING. ACCUMULATIONS OF AN INCH OR LESS ARE POSSIBLE.
VERY WEAK OMEGA EVIDENT IN FCST ACROSS MOST OF CWA TODAY...EXCEPT
ERN WISC ZONES WHERE LES WARNING CONTINUES. WIND ADV WILL BE LOW
END FOR THE MOST PART WITH GUSTS OF 40 MPH POSSIBLE...SUSPECT
HIGHER GUSTS MAY BE ISOLATED IN AREAL COVERAGE.
LAKE EFFECT...LATEST RUC ANALYSIS SHOWS 85H TEMPS AT -10C ACROSS LAKE
SUPERIOR SO LAKE SFC/85H TEMP DELTA T IS NEAR EMPIRICAL THRESHOLD
FOR INCREASING LAKE INDUCED CONVECTION. FCST STILL PUSHES 85H
THERMAL TROUGH OVER LAKE IN NEXT 24 HRS SO WILL MAINTAIN LES
WARNING. SPATIAL AND TEMPORAL TRENDS IN LAKE SNOW PARAMETER
SUGGESTS ACTIVITY SHOULD INCREASE SIGNIFICANTLY THIS AFTERNOON AND
CONTINUE OVERNIGHT.
PREV DISCUSSION... /ISSUED 426 AM CST SUN JAN 1 2012/
SHORT TERM...LATEST KDLH RADAR IMAGERY SHOWS THE SYNOPTICALLY
FORCED SNOW WINDING DOWN ACROSS THE NORTHLAND EARLY THIS
MORNING...WITH THE COLD FRONT NOW EAST OF OUR CWA. WINDS HAVE
TURNED OUT OF THE WEST/NORTHWEST AND HAVE STRENGTHEN ACROSS MOST
OF OUR FCST AREA. THIS TREND WILL CONTINUE TODAY AS MIXING
INCREASES CREATING BLUSTERY CONDITIONS. BECAUSE THE SNOW IS COMING
TO AN END...WE HAVE CANCELLED MANY OF THE WINTER WEATHER
ADVISORIES AND WARNINGS. HOWEVER BECAUSE OF THE STRENGTHENING
WINDS...WE HAVE ISSUED A WIND ADVISORY ALONG AND SOUTH OF THE
HIGHWAY 2 CORRIDOR. THE ADVISORY MAY NEED TO BE EXPANDED NORTHWARD
IF OBSERVATIONS WARRANT. HOWEVER THE MAIN FORECAST CONCERN FOR
THE SHORT TERM WILL BE THE POTENTIAL FOR LAKE EFFECT SNOW ALONG
THE SOUTHSHORE THROUGH MONDAY. NWP MODEL GUIDANCE CONTINUES TO
SUGGEST AN ADDITIONAL 6 TO 12 INCHES OF SNOW ACCUMULATION IS
POSSIBLE...WITH THE HEAVIER AMOUNTS ACROSS THE GOGEBIC RANGE.
THEREFORE WILL KEEP THE WARNING GOING FOR BAYFIELD...ASHLAND AND
IRON COUNTIES UNTIL 6PM MONDAY. BECAUSE OF THE STRONG WINDS...WE
WILL ALSO MENTION THE POSSIBILITY OF BLOWING SNOW. ELSEWHERE
CONDITIONS WILL BE MAINLY DRY ALTHOUGH COLD.
LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY.
THE SEVERAL-MONTH-OLD PATTERN OF A DEEP AND STRONG PACIFIC FLOW
ACROSS THE NORTHERN HALF OF THE UNITED STATES AND THE SOUTHERN
HALF OF CANADA WILL CONTINUE THROUGH THE WEEK AND COMING WEEKEND.
STRONG WARM AND DRY CHINOOKS WILL PERIODICALLY DEVELOP OVER THE
CENTRAL CANADIAN THROUGH THE MONTANA ROCKIES AND SPREAD ACROSS OUR
AREA... BRINGING SPRING LIKE WARMTH AND A DRY COLUMN. THE CURRENT
INTERRUPTION...COLD WEATHER WITHIN THE SEASONAL RANGE...THROUGH
TUESDAY...WILL BE FOLLOWED BY ABOVE FREEZING AFTERNOONS WEDNESDAY
THROUGH FRIDAY...WITH TEMPERATURES REMAINING IN THE 20S ACROSS THE
ENTIRE AREA THURSDAY NIGHT. A TEMPORARY SHOT OF LOWER TEMPERATURES
WILL FOLLOW THIS COMING WEEKEND. LITTLE IF ANY PRECIPITATION WILL
FALL DURING THIS PERIOD.
&&
.POINT TEMPS/POPS...
DLH 27 3 13 -4 / 60 10 0 0
INL 28 0 8 -12 / 60 20 0 0
BRD 26 6 16 1 / 60 10 0 0
HYR 27 7 14 -11 / 50 30 10 0
ASX 29 10 16 -3 / 70 60 40 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ033>038.
WI...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ001-006>009.
WINTER STORM WARNING UNTIL 6 PM CST MONDAY FOR WIZ002>004.
LS...GALE WARNING UNTIL 4 PM CST MONDAY FOR LSZ121-140>148.
&&
$$
SHORT TERM...CANNON
LONG TERM....GRANING
AVIATION...GRANING
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
947 AM CST SUN JAN 1 2012
.UPDATE...INCREASE POPS ACROSS MN ZONES THIS MORNING AS AREA OF
ENHANCED MOISTURE WITHIN 85/70H LATER ADVECTS SOUTHEASTWARD.
LATEST RUC13 ANALYSIS SHOWS -35C/50H COLD POOL IS MOVING ACROSS
CWA THIS MORNING. ACCUMULATIONS OF AN INCH OR LESS ARE POSSIBLE.
VERY WEAK OMEGA EVIDENT IN FCST ACROSS MOST OF CWA TODAY...EXCEPT
ERN WISC ZONES WHERE LES WARNING CONTINUES. WIND ADV WILL BE LOW
END FOR THE MOST PART WITH GUSTS OF 40 MPH POSSIBLE...SUSPECT
HIGHER GUSTS MAY BE ISOLATED IN AREAL COVERAGE.
LAKE EFFECT...LATEST RUC ANALYSIS SHOWS 85H TEMPS AT -10C ACROSS LAKE
SUPERIOR SO LAKE SFC/85H TEMP DELTA T IS NEAR EMPIRICAL THRESHOLD
FOR INCREASING LAKE INDUCED CONVECTION. FCST STILL PUSHES 85H
THERMAL TROUGH OVER LAKE IN NEXT 24 HRS SO WILL MAINTAIN LES
WARNING. SPATIAL AND TEMPORAL TRENDS IN LAKE SNOW PARAMETER
SUGGESTS ACTIVITY SHOULD INCREASE SIGNIFICANTLY THIS AFTERNOON AND
CONTINUE OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 700 AM CST SUN JAN 1 2012/
AVIATION...01012Z ISSUANCE...
VLIFR IN SCATTERED SNOW SHOWERS ALONG THE WISCONSIN SOUTH SHORE
FROM BAYFIELD PENINSULA EAST AND INLAND ABOUT 30 MILES. ELSEWHERE
MVFR IN COLD ADVECTION CLOUDS AND ISOLATED FLURRIES GOES BACK TO
THE RED RIVER VALLEY AND WILL PERSIST ACROSS MOST OF THE AREA INTO
THE EVENING. VFR IN LIFTING AND SCATTERING CLOUDS FROM WEST TO
EAST LATE TONIGHT.
PREV DISCUSSION... /ISSUED 426 AM CST SUN JAN 1 2012/
SHORT TERM...LATEST KDLH RADAR IMAGERY SHOWS THE SYNOPTICALLY
FORCED SNOW WINDING DOWN ACROSS THE NORTHLAND EARLY THIS
MORNING...WITH THE COLD FRONT NOW EAST OF OUR CWA. WINDS HAVE
TURNED OUT OF THE WEST/NORTHWEST AND HAVE STRENGTHEN ACROSS MOST
OF OUR FCST AREA. THIS TREND WILL CONTINUE TODAY AS MIXING
INCREASES CREATING BLUSTERY CONDITIONS. BECAUSE THE SNOW IS COMING
TO AN END...WE HAVE CANCELLED MANY OF THE WINTER WEATHER
ADVISORIES AND WARNINGS. HOWEVER BECAUSE OF THE STRENGTHENING
WINDS...WE HAVE ISSUED A WIND ADVISORY ALONG AND SOUTH OF THE
HIGHWAY 2 CORRIDOR. THE ADVISORY MAY NEED TO BE EXPANDED NORTHWARD
IF OBSERVATIONS WARRANT. HOWEVER THE MAIN FORECAST CONCERN FOR
THE SHORT TERM WILL BE THE POTENTIAL FOR LAKE EFFECT SNOW ALONG
THE SOUTHSHORE THROUGH MONDAY. NWP MODEL GUIDANCE CONTINUES TO
SUGGEST AN ADDITIONAL 6 TO 12 INCHES OF SNOW ACCUMULATION IS
POSSIBLE...WITH THE HEAVIER AMOUNTS ACROSS THE GOGEBIC RANGE.
THEREFORE WILL KEEP THE WARNING GOING FOR BAYFIELD...ASHLAND AND
IRON COUNTIES UNTIL 6PM MONDAY. BECAUSE OF THE STRONG WINDS...WE
WILL ALSO MENTION THE POSSIBILITY OF BLOWING SNOW. ELSEWHERE
CONDITIONS WILL BE MAINLY DRY ALTHOUGH COLD.
LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY.
THE SEVERAL-MONTH-OLD PATTERN OF A DEEP AND STRONG PACIFIC FLOW
ACROSS THE NORTHERN HALF OF THE UNITED STATES AND THE SOUTHERN
HALF OF CANADA WILL CONTINUE THROUGH THE WEEK AND COMING WEEKEND.
STRONG WARM AND DRY CHINOOKS WILL PERIODICALLY DEVELOP OVER THE
CENTRAL CANADIAN THROUGH THE MONTANA ROCKIES AND SPREAD ACROSS OUR
AREA... BRINGING SPRING LIKE WARMTH AND A DRY COLUMN. THE CURRENT
INTERRUPTION...COLD WEATHER WITHIN THE SEASONAL RANGE...THROUGH
TUESDAY...WILL BE FOLLOWED BY ABOVE FREEZING AFTERNOONS WEDNESDAY
THROUGH FRIDAY...WITH TEMPERATURES REMAINING IN THE 20S ACROSS THE
ENTIRE AREA THURSDAY NIGHT. A TEMPORARY SHOT OF LOWER TEMPERATURES
WILL FOLLOW THIS COMING WEEKEND. LITTLE IF ANY PRECIPITATION WILL
FALL DURING THIS PERIOD.
AVIATION...
MODERATE SNOW MOVING ACROSS NW WI AT FCST TIME. THE
WEST EDGE OF SNOW SHOULD CLEAR HYR BY 00Z. T THE OTHER TAF
SITES...MVFR TO IFR CIGS WITH MVFR VSBYS WILL BE COMMON TONIGHT
AND SUNDAY MORNING. ALSO...WINDS WILL INCREASE OVERNIGHT TO 20-30
MPH OUT OF THE NORTHWEST. THE HIGH WINDS WILL REMAIN ACROSS THE
AREA BEFORE TAPERING OFF LATE SUNDAY.
&&
.POINT TEMPS/POPS...
DLH 27 3 13 -4 / 60 10 0 0
INL 28 0 8 -12 / 60 20 0 0
BRD 26 6 16 1 / 60 10 0 0
HYR 27 7 14 -11 / 50 30 10 0
ASX 29 10 16 -3 / 70 60 40 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ033>038.
WI...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ001-006>009.
WINTER STORM WARNING UNTIL 6 PM CST MONDAY FOR WIZ002>004.
LS...GALE WARNING UNTIL 4 PM CST MONDAY FOR LSZ121-140>148.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION
NWS HASTINGS NE
200 PM CST SUN JAN 1 2012
.UPDATE...KGRI...KAUH AND KJYR AND HAVE EITHER BEEN CLOSE OR EXCEEDED
WIND ADVISORY CRITERIA THROUGH THE PAST HOUR OR SO. LATEST RUC
GUIDANCE SUGGESTS THE WESTERN PERIPHERY OF STRONGEST 850-700MB
WINDS HAVE PUSHED A TAD FARTHER SOUTH/SOUTHWEST THAN PREVIOUSLY
ANTICIPATED AND AS A RESULT...STRONGER WIND GUSTS AT THE SURFACE
ARE ALSO BEING OBSERVED FARTHER SOUTH/SOUTHWEST. RUC GUIDANCE
SUGGESTS THE AXIS OF STRONGEST 850-700MB WINDS SHOULD DIMINISH
AND PUSH EAST SOME THROUGH THE NEXT 2-3 HOURS...BUT FEELING
CONFIDENT ENOUGH TO EXPAND THE WIND ADVISORY CLOSER TO THE I-80
CORRIDOR. WINDS WILL ALSO RAPIDLY DIMINISH TOWARDS SUNSET AS THE PBL
DECOUPLES FROM THE STRONGER WINDS JUST ABOVE THE SURFACE...THUS
KEPT THE ADVISORY EXPIRATION TIME SET AT 00Z.
&&
.PREV DISCUSSION... /ISSUED 1158 AM CST SUN JAN 1 2012/
UPDATE...MIDDAY SURFACE ANALYSIS INDICATES A RIDGE OF HIGH
PRESSURE CONTINUES WORKING INTO THE REGION FROM THE NORTHWEST. THE
LOW LEVEL WIND FIELD ACROSS OUR AREA REMAINS FROM THE NORTHWEST AS
A RESULT. THESE WINDS HAVE INCREASED SOME THROUGH THE PAST HOUR OR
TWO AND WITH AFTERNOON PBL MIXING EXPECTED TO CLIMB TO NEAR
800MB...CURRENTLY EXPECT THE GUST POTENTIAL TO INCREASE TO NEAR
35KTS ACROSS MUCH OF THE CWA DURING THE AFTERNOON...WITH SLIGHTLY
STRONGER WINDS POSSIBLE ACROSS OUR EXTREME NORTH/NORTHEAST. GIVEN
THIS WILL KEEP THE CURRENT WIND ADVISORY GOING AS IS.
PREV DISCUSSION... /ISSUED 1116 AM CST SUN JAN 1 2012/
AVIATION...18Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE
NEXT 24 HOURS. HIGH LEVEL CLOUDS NO LOWER THAN 20000FT AGL ARE
EXPECTED AT TIMES. SURFACE WINDS WILL INCREASE IN INTENSITY THIS
AFTERNOON AS THE LOW LEVEL PRESSURE GRADIENT INCREASES SOMEWHAT.
AFTERNOON PBL MIXING TO NEAR 800MB WILL ALSO PROMOTE A GUST POTENTIAL
NEAR 35KTS. SURFACE WINDS WILL SUBSIDE TOWARDS SUNRISE AS THE LOW
LEVEL PRESSURE GRADIENT WEAKENS AND THE PBL HEIGHT DECREASES.
VISIBILITY RESTRICTIONS ARE NOT EXPECTED THROUGH THE NEXT 24 HOURS.
PREV DISCUSSION... /ISSUED 315 AM CST SUN JAN 1 2012/
SHORT TERM...TODAY THROUGH 12Z WEDNESDAY. THE MAIN CONCERN WILL BE
WINDS TODAY. NORTHWESTERLY FLOW WILL BE IN PLACE ALOFT ACROSS THE
CENTRAL PLAINS TODAY WITH A LARGE RIDGE OVER THE WESTERN UNITED
STATES. AT THE SURFACE...LOW PRESSURE OVER EASTERN IOWA WILL
CONTINUE TO MOVE NORTHEAST...WHILE HIGH PRESSURE BUILDS INTO THE
HIGH PLAINS. THIS WILL KEEP A FAIRLY TIGHT SURFACE PRESSURE
GRADIENT IN PLACE...WITH THE TIGHTEST GRADIENT EXPECTED TO BE IN
THE NORTHEAST PORTION OF THE FORECAST AREA. NAM BUFR SOUNDINGS
SHOW GOOD MIXING TODAY AS LOW LEVEL LAPSE RATES STEEPEN...AND
MOMENTUM TRANSFER POINTS TO THE STRONGEST WINDS FROM KOFK TO
KODX. AFTER COORDINATION WITH SURROUNDING OFFICES...HAVE DECIDED
TO GO AHEAD AND HOIST A WIND ADVISORY FOR VALLEY...GREELEY AND
NANCE COUNTIES. THOSE AREAS APPEAR TO HAVE THE BEST CHANCE OF
SEEING GUSTS TO AROUND 45 MPH...THOUGH IT COULD BE MARGINAL AT
TIMES. IN REGARDS TO HIGHS...HAVE GENERALLY GONE WITH READINGS IN
THE UPPER 30S TO MID 40S.
COLD HIGH PRESSURE WILL BE IN PLACE TONIGHT. THIS WILL BRING CLEAR
SKIES AND LIGHT WINDS...WHICH WILL HELP TEMPERATURES FALL NICELY
OVERNIGHT. A BLEND OF GUIDANCE BRINGS LOWS INTO THE 8 TO 18
DEGREE RANGE...AND SEE NO REASON TO STRAY TOO FAR FROM THOSE
VALUES.
THE UPPER RIDGE SLIDES EAST ON MONDAY WHICH WILL HELP BRING WARMER
AIR ALOFT BACK INTO THE CENTRAL PLAINS. H85 TEMPERATURES RISE
APPROXIMATELY 6 DEGREES CELSIUS...BUT MIXING IS WORSE THAN TODAY
AND THE COOL START TO THE DAY WILL ALSO HAVE AN IMPACT ON HIGHS.
WILL SHOW MAX TEMPERATURES IN THE MID 30S TO LOWER 40S.
H85 WARM AIR ADVECTION CONTINUES THROUGH MONDAY NIGHT. THIS
SHOULD HELP TEMPERATURES STEADY OUT OVERNIGHT AFTER THE INITIAL
DROP DURING THE EVENING. HAVE GONE WITH LOWS IN THE TEENS AND
LOWER 20S ACROSS THE FORECAST AREA.
A WAVE TOPS THE H5 RIDGE ON TUESDAY WHICH WILL PUSH A COLD FRONT
THROUGH THE AREA. DESPITE THE COLD AIR ADVECTION THAT TAKES
HOLD...TEMPERATURES SHOULD WARM UP SOME FROM MONDAY WITH A GOOD
DOWNSLOPE COMPONENT TO THE WINDS. WILL AIM FOR HIGHS IN THE MID
40S TO LOWER 50S.
LONG TERM...WEDNESDAY THROUGH SATURDAY. WITH THE MAJORITY OF THIS
TIME FRAME CARRYING ESSENTIALLY ZERO RISK FOR PRECIPITATION...THE
PRIMARY CHALLENGE IS JUST HOW WARM TO GO WITH HIGH TEMPERATURES AS
THIS FAIRLY NOTABLE STRETCH OF EARLY-MID WINTER MILDNESS CONTINUES.
FOR WEDNESDAY/WEDNESDAY NIGHT...00Z ECMWF/GFS RUNS ARE IN GOOD
AGREEMENT THAT THIS REMAINS THE TIME FRAME OF THE ENTIRE 7-DAY
FORECAST WITH THE HIGHEST MID LEVEL HEIGHTS/MOST PRONOUNCED RIDGING
OVER THE CENTRAL CONUS...IN BETWEEN A TROUGH OVER THE NORTHEAST AND
AN INCOMING SHORTWAVE INTO THE PAC NORTHWEST REGION. AT THE
SURFACE...BROAD FAIRLY LIGHT BUT STEADY WESTERLY DOWNSLOPE FLOW IS
THE STORY...AS H85 TEMPS RISE INTO THE 7-10C RANGE DURING THE
AFTERNOON. ALTHOUGH FULL MIXING WILL LIKELY FALL SHORT OF THIS
LEVEL...SAW NO REASON NOT TO NUDGE UP HIGH TEMPS 1-2 DEGREES FROM
PREVIOUS FORECAST...NOW DEPICTING AT LEAST LOW 50S EVERYWHERE...AND
MID 50S IN SOME WESTERN/SOUTHERN COUNTIES. ULTIMATELY...MID 50S
MIGHT PROVE TO BE MORE WIDESPREAD THAN ADVERTISED...ASSUMING PASSING
CIRRUS ISN/T THICK ENOUGH TO INTERFERE. FOR LOWS WED NIGHT...HELD
ALL AREAS UP IN THE LOW 30S.
THURS/THURS NIGHT...THIS STILL LOOKS LIKE THE OVERALL WARMEST DAY
OF THE FORECAST PERIOD. ALTHOUGH THE MID LEVEL RIDGE GETS FLATTENED
BY LOW AMPLITUDE DISTURBANCES TRACKING FROM THE PAC NORTHWEST ACROSS
THE NORTHERN ROCKIES/NORTHERN PLAINS...THE SITUATION IN THE LOW
LEVEL REMAINS MUCH THE SAME WITH PERSISTENT WESTERLY FLOW. THE
ECMWF/GFS BOTH CONTINUE TO ADVERTISE 850MB TEMPS SOARING INTO THE
+13-15C RANGE DURING THE DAY...WHICH IS QUITE NOTABLE FOR EARLY
JANUARY. AGAIN...NOT EXPECTING FULL MIXING UP TO THIS LEVEL...BUT
STILL BUMPED HIGHS ANOTHER DEGREE OR SO ABOVE PREVIOUS FORECAST WITH
UPPER 50S MOST AREAS...AND INTRODUCED 60 IN THE FAR SOUTHWEST.
AGAIN...THIS COULD ULTIMATELY PROVE TO BE A SOMEWHAT CONSERVATIVE
FORECAST...WITH POTENTIAL CERTAINLY THERE FOR WIDESPREAD LOW 60S OR
EVEN HIGHER...WHICH COULD EVEN THREATEN RECORD HIGHS FOR JAN 5TH IN
PARTS OF THE CWA.
FRIDAY/FRIDAY NIGHT...IN THE WAKE OF A COLD FRONT THAT PUSHES SOUTH
ACROSS THE AREA THURS NIGHT...FRIDAY HIGHS LOOK TO AVERAGE 5-10
DEGREES COOLER THAN THURS...BUT STILL WELL-ABOVE NORMAL...AND KEPT
SIMILAR TO PREV FORECAST WITH UPPER 40S NORTHWEST TO LOW 50S SOUTH.
IF THE ECMWF ENDS UP MORE CORRECT WITH ITS LESS ROBUST COLD AIR
ADVECTION THAN THE GFS...THIS MIGHT BE YET ANOTHER DAY WE ARE
UNDER-FORECASTING HIGHS...AS IT MIGHT END UP MORE LIKE MID 50S MOST
AREAS. BY FRIDAY NIGHT...MODELS START TO DIVERGE A BIT WITH EXACTLY
WHAT HAPPENS WITH INDIVIDUAL SHORTWAVES DROPPING THROUGH THE NORTH
CENTRAL/NORTHWEST CONUS...WITH THE ECMWF ACTUALLY DEPICTING SOME
LIGHT PRECIP POSSIBLY FLIRTING WITH MAINLY THE SOUTHWEST CWA LATE
FRIDAY NIGHT WITHIN A SOUTHWARD-SAGGING UPPER LEVEL JET AXIS. FOR
NOW CONFIDENCE IN PRECIP IS WAY TOO LOW TO INTRODUCE A MENTION.
SATURDAY...MODELS CONTINUE TO DIVERGE WITH THE DETAILS...BUT GENERAL
CONSENSUS IS THAT GREATEST FORCING FOR PRECIP PRODUCTION REMAINS
TIED TO SHORTWAVES WELL EAST OF THE CWA...AND ALSO TO THE SOUTHWEST
PER THE ECMWF. WILL CONTINUE TO KEEP IT DRY FOR NOW. CONFIDENCE IN
HIGH TEMPS IS NOT GREAT...SO STUCK WITH CONSENSUS BLEND WITH UPPER
30S NORTH TO MID 40S SOUTH. LOOKING OUT THROUGH ROUGHLY JAN
10TH...ALTHOUGH THERE ARE NO ANOMALOUSLY WARM DAYS EVIDENT...LOOKS
LIKE MORE DAYS IN THE 40S OR 30S...AND NO SIGNS OF A MAJOR PRECIP
EVENT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ039>041-046>049-
062>064.
KS...NONE.
&&
$$
UPDATE/AVIATION...BRYANT
SHORT TERM...KING
LONG TERM...PFANNKUCH
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1159 AM CST SUN JAN 1 2012
.UPDATE...
SFC OBS FROM KVTN...KANW AND NEDOR HAVE COME UP TO WIND ADVISORY
CRITERIA. THE RUC SUGGESTS WIND ADVISORY SPEEDS THIS AFTN IN THAT
AREA SO THE ADVISORY HAS BEEN PUSHED FARTHER WEST TO INCLUDE
EASTERN CHERRY COUNTY.
&&
.PREV DISCUSSION... /ISSUED 540 AM CST SUN JAN 1 2012/
AVIATION...
FOR THE KLBF AND KVTN TERMINALS THROUGH 12Z MONDAY.
WITH THE EXCEPTION OF SOME MID LEVEL CLOUDINESS OVER NORTHERN
NEBRASKA THIS MORNING...MOSTLY CLEAR SKIES ARE EXPECTED TODAY AND
TONIGHT ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. NORTHWESTERLY
WINDS WILL BE GUSTY TODAY...ESPECIALLY EAST OF A LINE FROM KANW TO
KBBW. IN THESE AREAS...SURFACE WIND GUSTS UP TO 40 KTS ARE POSSIBLE
BETWEEN 16Z AND 00Z TODAY. ELSEWHERE...WIND GUSTS UP TO 30 KTS ARE
POSSIBLE TODAY WITH WINDS DIMINISHING TO UNDER 10 KTS TONIGHT.
PREV DISCUSSION... /ISSUED 338 AM CST SUN JAN 1 2012/
SYNOPSIS...
STRONG LOW PRESSURE SYSTEM...THAT BROUGHT THE GUSTY WINDS
YESTERDAY...HAS PUSHED INTO THE MID MISS RVR VALLEY. MEANWHILE
HIGH PRESSURE AND MOSTLY CLEAR SKIES MOVING EAST ACROSS THE
CENTRAL/NORTHERN ROCKIES. SKIES HAVE CLEARS OVER THE
CWA...HOWEVER STILL GETTING SOME MIXING WITH TIGHT PRESSURE
GRADIENT BETWEEN THE HIGH AND LOW...HELPING TO HOLD TEMPS IN 20S
FOR THE MOST PART AT 09Z...EVEN A FEW LOW 30S OVER CENTRAL NEB.
DISCUSSION...
NEW YEAR TO START OFF SEASONAL TEMPS...DRY...AND
WINDY...ESPECIALLY OVER NORTH CENTRAL. 500 MB RIDGE ANCHORED OVER
THE WESTERN STATES WITH A DEEP TROUGH OVER THE EAST. THIS
CONTINUES NORTHWEST FLOW OVER THE CWA TODAY. COLD AIR BEHIND
YESTERDAYS COLD FRONT HAS BROUGHT 850 TEMPS DOWN TO AROUND -2C IN
SW NEB TO NEAR -10C IN N CENTRAL. LIMITED RELIEF IN TEMPS EXPECTED
TODAY...HOWEVER RANGE OF TEMPS TODAY NOT EXPECTED TO BE AS
GREAT AT 850 MB TEMPS WOULD SUGGEST...DUE TO BETTER MIXING OVER
NORTH CENTRAL. AS A RESULT OF THE MIXING...EXPECT WINDS TO PUSH
NEAR ADVISORY CRITERIA. MODELS IN GOOD AGREEMENT WITH 850 MB WINDS
AROUND 40KTS OVER N CENTRAL. MOS GUIDANCE HIGHEST FOR ONL AND WILL
ISSUE AN ADVISORY TO COVER THE NE 4 COUNTIES. POSSIBLE EXPANSION
MAYBE NEEDED FOR THE NEXT TIER TO THE WEST OF COUNTIES...HOWEVER
WINDS HAVE DIMINISHED MORE THERE ALREADY AND EXPECT THIS TO
CONTINUE THROUGH THE DAY. ANOTHER LIMITING FACTOR WILL BE AN
INCREASE OF MID/HIGH CLOUDS. WATER VAPOR HAS DECENT PLUM OF
MOISTURE ROUNDING THE RIDGE AND WILL ATTEMPT TO CROSS THE ROCKIES.
SO FAR MOISTURE HAS STRUGGLES TO CROSS THE DIVIDE...HOWEVER...AS
WAS THE CASE MUCH OF LAST WEEK...EXPECT SOME MOISTURE/CLOUDS TO
MAKE IT OVERHEAD DURING THE AFTERNOON. THIS WILL ALSO PUT A DAMPER
ON THE MIXING FROM WEST TO EAST AS TEMPS FAIRLY UNIFORM OVER NORTH
CENTRAL IN THE MID 30S.
HIGH PRESSURE SETTLES OVERHEAD TONIGHT WITH WINDS EXPECTED TO
DECOUPLE AND TEMPS TO PLUMMET. TEMPS IN THE SINGLE DIGITS TO LOW
TEENS ARE EXPECTED.
COLD TEMPS ARE SHORT LIVED AS HIGH QUICKLY SLIDES SOUTH WITH SE
WINDS DEVELOPING FOR MONDAY. HIGHS ON MONDAY NOT TOO FAR FROM
TODAY...BUT THE WARM AIR IS BUILDING TO THE SW. WARM FRONT SURGES
ACROSS THE AREA BY TUESDAY WITH HIGHS TUESDAY INTO THE 50S FOR
MOST OF THE AREA. UNSEASONABLE WARM TEMPS AND DRY CONTINUES
THROUGH MID WEEK. WARMEST DAY LOOKS TO BE THURSDAY WHERE SOME
HIGHS IN THE 60S LIKELY. RECORDS ARE IN THE MID 60S AND WILL
CONTINUE TO MONITOR. CURRENT FORECAST IS STILL BELOW RECORDS...BUT
NOT BY MUCH.
NEXT COLD FRONT ARRIVES FRIDAY WITH TEMPS ON THE DOWNWARD
SLIDE...BUT NO BITTER ARCTIC COLD YET. HIGHS BEHIND THE FRONT ON
SATURDAY AND SUNDAY IN THE 30S TO AROUND 40...CLOSE TO NORMAL THIS
TIME OF YEAR. LIMITED MOISTURE WITH FRONTAL PASSAGE...AND BEST
ENERGY IN THE NORTHERN STREAM...NEAR THE US/CAN BORDER AND WILL
CONTINUE A DRY FORECAST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 6 PM CST
THIS EVENING FOR NEZ005>010-027>029.
&&
$$
SHORT TERM...CDC
AVIATION/EXTENDED...TAYLOR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
326 AM EST TUE JAN 3 2012
.SYNOPSIS...
AN ARCTIC AIRMASS WILL BRING BLUSTERY WEATHER CONDITIONS TODAY.
ARCTIC HIGH PRESSURE WILL GRADUALLY BUILD EAST AND BECOME CENTERED
OVER THE AREA BY WEDNESDAY. THE HIGH WILL MOVE OFFSHORE SOUTH OF
THE AREA THURSDAY THROUGH SATURDAY. A COLD FRONT WILL PASS THROUGH
THE AREA ON SUNDAY.
&&
.NEAR TERM /TODAY/...
AS OF 3 AM TUE...CAA WELL UNDERWAY ACROSS E NC AS ARCTIC FRONT HAS
PASSED OVER THE COASTAL WATERS. SOME SCT FLURRIES CONTINUE ACROSS
THE SW PORTIONS OF THE FA AS KDPL HAS REPORTED OCNL -SN...THOUGH
VSBYS ABOVE 5SM SUGGEST VERY LIGHT SNOW FALLING. NO ACCUM IS
EXPECTED THROUGH EARLY THIS MORNING. VORT MAX PIVOTING EASTWARD
IN ASSOCIATION WITH DEEP E CONUS TROUGH RESPONSIBLE FOR AREA OF
LIFT/FGEN IN THE H85-H70 LEVEL. X-SECTION ANALYSIS OFF RUC SHOWS
DECENT LIFT COINCIDENT WITH DGZ OCCURRING ACROSS THE E NC...AND AS
THIS MOVES EAST MAY BE JUST ENOUGH TO OVERCOME THE DRY LOW LEVELS
TO PRODUCE SOME SNOW SHOWERS/FLURRIES AS SCT CIGS AROUND 2K FT
SUGGEST.
THE MAIN STORY TODAY WILL BE THE COLD AND WINDY CONDITIONS.
CONFIDENCE IS HIGH IN MAX T`S REACHING THE MID-UPR 30S AREA WIDE
WITH MODEL SUITES IN GOOD AGREEMENT...EVEN DESPITE MOSTLY SUNNY
SKIES. GUSTY NW WINDS ON CONTINUING STRONG CAA WILL MAKE FOR WIND
CHILL VALS IN THE MID- UPR 20S THIS AFTERNOON. UNIDERECTIONAL WIND
PROFILES IN THE WELL MIXED BOUNDARY LAYER SUGGEST WINDS AOA 25KT
ALOFT MAKING IT TO THE SFC IN THE FORM OF GUSTS DURING PEAK
DAYTIME HEATING THIS AFTERNOON. HIGHEST WINDS STILL EXPECTED
ACROSS THE OBX WITH MARGINAL WIND ADVISORY CRITERIA BEING MET
THERE...ESPECIALLY ACROSS THE EXPOSED SOUNDSIDE AREAS.
&&
.SHORT TERM /TONIGHT/...
AS OF 3 AM TUE...WINDS BEGIN TO DIMINISH THIS EVENING AS DEEP
TROUGH AXIS SHIFTS OFF THE COASTAL WATERS AND CAA DIMINSHES. WINDS
WILL REMAIN HIGH ACROSS OBX AS DEEPENING LOW WELL OFF THE EAST
COAST PROVIDES TIGHTER GRADIENT HERE. SFC HIGH PRES WILL RIDGE
INTO THE REGION FROM THE WEST...WITH WINDS BECOMING LIGHT AFTER
06Z. WITH TD`S EXPECTED INTO THE SINGLE DIGITS TONIGHT...TEMPS
WILL PLUMMET INTO THE MID TO UPPER TEENS INLAND WITH 20S OBX DUE
TO CONTINUED MIXING HERE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 230 AM TUE...SFC HIGH PRESSURE WILL CONTINUE TO BUILD OVER
THE SE WED. TEMPERATURES WILL REMAIN ABOUT 10 DEG BELOW NORMAL FOR
WED...WITH HIGHS LIKELY IN THE UPPER 30S TO LOWER 40S. A WEAK
SHORTWAVE WILL MOVE THROUGH THE REGION WED NIGHT INTO THU.
MOISTURE CONTINUES TO LOOK VERY LIMITED WITH THIS FEATURE SO AT
THIS TIME DO NOT ANTICIPATE ANY IMPACTS ON SENSIBLE WX...OTHER
THAN INCREASE IN CLOUD COVER. EXPECT A GRADUAL TEMP WARMUP THROUGH
THE PERIOD AS LOW LEVEL THICKNESS VALUES AND UPPER HEIGHTS BUILD.
BY THE WEEKEND TEMPS LIKELY REBOUNDING INTO UPPER 50S TO LOWER
60S.
THE NEXT OPPORTUNITY FOR RAIN WILL COME SAT NIGHT INTO SUN AS
SOUTHERN STREAM MOISTURE MERGES WITH A NORTHERN STREAM TROUGH
DIGGING ACROSS THE MID WEST. UNCERTAINLY IN THE FORECAST INCREASES
EARLY NEXT WEEK AS MODELS NOT IN BEST AGREEMENT RESOLVING A
POSITIVELY TROUGH DIGGING INTO THE SOUTH. SOME SOLUTIONS DEVELOP A
CUTOFF LOW ACROSS ERN TX AND THE DEEP SOUTH MON INTO TUE WHILE
OTHER SOLUTIONS ARE MORE PROGRESSIVE KEEPING AN OPEN WAVE. HAVE
FOLLOWED HPC GUIDANCE FAIRLY CLOSELY LATE IN THE PERIOD UNTIL
MODELS ARE IN BETTER AGREEMENT.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 3 AM TUE...MID CLOUD DECK ASSOCIATED WITH SURFACE TROUGH
WILL CONTINUE TO LINGER THROUGH ABOUT 12Z. CEILINGS SHOULD
GENERALLY BE AROUND 5 TO 7K FT AND SHOULD SCATTER OUT BY TUESDAY
MORNING. DO NOT SEE CLOUD BASES GOING BELOW THE VFR CATEGORY AND
ANY FLURRIES THAT OCCUR THROUGH 12Z WILL NOT LIMIT VSBYS BELOW 6
MI.
GUSTY WINDS AROUND 25 KT WILL BE COMMON DURING THE DAYTIME HOURS
AS STRONG CAA WITH UNIDIRECTIONAL FLOW THROUGH THE BOUNDARY LAYER
WILL BE MAXIMIZED THROUGH AROUND 22Z. WINDS WILL DIMINISH QUITE
RAPIDLY BY 00Z...BECOMING LIGHT AFTER 02Z.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 230 AM TUE...PREDOMINATE VFR CONDITIONS EXPECTED THROUGH THE
PERIOD.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 3 AM TUE...GALE FORCE WINDS STILL APPEAR LIKELY THROUGH
TODAY AS DEEP TROUGH TRANSLATES EAST THROUGH THE COASTAL WATERS
TODAY. THIS WILL BE ACCOMPANIED BY STRONG CAA. WITH A WELL MIXED
MBL TODAY...SHOULD SEE SUSTAINED WINDS AOA 30KT WITH GUSTS ABOVE
35 KT THROUGH MUCH OF TODAY OVER ALL THE WATERS INCLUDING THE
SOUNDS. WINDS SLOWLY DIMINISH THIS EVENING AS TROUGH AXIS SHIFTS
EAST OVER THE WESTERN ATLANTIC...AND GALES WILL BE REPLACED WITH
SCA OVER THE SOUNDS AROUND 00Z...AND A BIT LATER FOR THE COASTAL
WATERS. SEAS WILL BE MAXIMIZED AT 7 TO 8 FEET OVER THE OUTER
NORTHERN AND CENTRAL WATERS TODAY.
MAXIMUM WATER RISES OF 1 TO 2 FEET STILL EXPECTED ON SOUNDSIDE OF
THE OBX TODAY DUE TO THE STRONG NW WINDS...WITH SUBSEQUENT LOW
WATER LEVELS OF 1 TO 2 FEET ACROSS THE WESTERN SOUNDS AND THE
RIVER BASINS...ESPECIALLY THE TAR AND NEUSE.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
AS OF 230 AM TUE...SFC HIGH PRESSURE WILL CONTINUE TO BUILD OVER
THE SE US THROUGH THE FIRST PART OF THE PERIOD. NW/W WINDS WILL
CONTINUE TO DIMINISH THROUGH THE DAY...WITH SUBSEQUENT SEAS
SUBSIDING BELOW 6FT WED MORNING. A WEAK SHORTWAVE WILL MOVE
THROUGH THE WATERS WED NIGHT/THU. PREDOMINATE W/SW WINDS EXPECTED
LATE WED THROUGH SAT. MODELS CONTINUE TO KEEP WINDS AOB 20 KT AND
SEAS AOB 5 FT...SO NOT ANTICIPATING ADDITIONAL SCA`S AFTER WED
MORNING. NEXT SIGNIFICANT FRONTAL SYSTEM WILL LIKELY APPROACH THE
WATERS LATE THIS WEEKEND.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...WIND ADVISORY FROM 9 AM THIS MORNING TO 5 PM EST THIS
AFTERNOON FOR NCZ103-104.
COASTAL FLOOD ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NCZ103-104.
MARINE...LOW WATER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ130-
135.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR AMZ130-135.
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR AMZ150-152-154-
156-158.
&&
$$
SYNOPSIS...TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...SK/CQD
AVIATION...CQD/TL
MARINE...CQD/TL
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1130 PM CST MON JAN 2 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
257 PM CST MON JAN 2 2012
MAIN FORECAST CONCERNS ARE CLOUD COVER AND TEMPERATURES...ALONG WITH
WHETHER PRECIPITATION CAN OCCUR TUESDAY NIGHT.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED A SHORTWAVE TROUGH OVER THE PACIFIC NORTHWEST...RIDGING FROM
THE SOUTHWEST U.S. NORTHWARD INTO SASKATCHEWAN...AND DEEP TROUGHING
FROM SOUTHEAST CANADA SOUTHWARD INTO THE SOUTHEAST U.S.. COLD AIR
ASSOCIATED WITH THIS DEEP TROUGH IS FIRMLY ENTRENCHED OVER THE
FORECAST AREA...WITH 850MB TEMPS PER 12Z RAOBS AROUND -18C. GRB
SOUNDING REFLECTS THE COLD ADVECTION SEEN AS WELL...NOTED BY 24 HOUR
TEMPERATURE DROP OF 10-15C FROM THE SURFACE TO 400MB. TROPOPAUSE HAS
ALSO BEEN LOWERED TO 425MB. CLOUD COVER...RELATED TO MOISTURE STUCK
BELOW THE COLD FRONTAL INVERSION NEAR 800MB PER 12Z GRB/MPX
SOUNDINGS...HAS BEEN SLOWLY DISSIPATING DUE TO A COMBINATION OF
DAYTIME MIXING AND DRY AIR ADVECTING SOUTH OUT OF NORTHERN ONTARIO.
TO THE WEST...A RIDGE OF HIGH PRESSURE WAS LOCATED OVER THE EASTERN
DAKOTAS. FURTHER WEST...WARM ADVECTION IS TAKING PLACE ALONG THE LEE
OF THE ROCKIES...NOTED BY 12Z SOUNDINGS FROM GGW AND UNR WITH 850MB
TEMPS AROUND 0C. CIRRUS HAS BEEN PRESENT IN THESE AREAS TOO...COMING
FROM PACIFIC MOISTURE TOPPING THE UPPER RIDGING THERE.
TONIGHT AND TUESDAY...UPPER RIDGE SEEN OVER MONTANA INTO
SASKATCHEWAN IS PROGGED TO PUSH EAST DURING THIS PERIOD...IN
RESPONSE TO THE SHORTWAVE TROUGH OVER THE PACIFIC NORTHWEST MOVING
INTO WESTERN MINNESOTA BY 00Z WEDNESDAY. THE UPPER RIDGE AXIS SHOULD
CROSS THE FORECAST AREA MID-DAY TUESDAY. WITH THE UPPER RIDGING
BUILDING IN PROVIDING PLENTY OF SUBSIDENCE...NO PRECIPITATION IS
ANTICIPATED. EVEN AFTER THE UPPER RIDGE PASSES LATE TUESDAY AND
500MB HEIGHTS BEGIN TO FALL...THE PRESENCE OF SO MUCH DRY AIR
BROUGHT IN BY THE CURRENT UPPER TROUGH WILL KEEP THINGS DRY AND ANY
WARM ADVECTION CLOUDS TO MID OR HIGH LEVEL. CONCERN TONIGHT IS HOW
LOW TEMPERATURES MAY END UP WITH CLEAR SKIES LIKELY AND THE SURFACE
RIDGE MOVING IN OVERNIGHT. WOULD NOT BE SURPRISED IF TYPICAL COLD
SITES NORTH OF I-94...WHERE MORE THAN A TRACE OF SNOW EXISTS ON THE
GROUND...DROP TO 5 TO 10 BELOW ZERO. MOST OF THE REST OF THE AREA
SHOULD SEE LOWS IN THE SINGLE DIGITS ABOVE ZERO...WITH OTHER TYPICAL
COLD SPOTS IN WISCONSIN DROPPING TO 0 TO 5 BELOW. INCREASING SOUTH
WINDS WILL BRING IN WARMER AIR FOR TUESDAY...CAUSING 850MB TEMPS TO
CLIMB TO -2 TO -6C BY 18Z. SOME OF THIS WARM AIR MAY BE CAPPED
OFF...HELPED TOO BY THE INCREASE IN MID AND HIGH CLOUDS LATER IN THE
DAY PREVENTING MIXING. THEREFORE...HIGHS ARE ONLY FORECAST IN THE
20S. A FEW SITES IN NORTHEAST IOWA COULD TOP 30...THOUGH...CLOSER TO
THE WARMEST AIR MOVING IN AND BEING SNOW-FREE.
TUESDAY NIGHT THROUGH THURSDAY...SHORTWAVE TROUGH OVER WESTERN
MINNESOTA IS WELL AGREED UPON TO MOVE SOUTHEAST ACROSS THE FORECAST
AREA TUESDAY NIGHT...WITH 500MB HEIGHTS SLOWLY BUILDING IN ITS WAKE
THROUGH THURSDAY. THE RISING HEIGHTS ARE IN RESPONSE TO A SHORTWAVE
TROUGH MOVING INTO BRITISH COLUMBIA AND THE PACIFIC NORTHWEST...
PUSHING RIDGING THAT DEVELOPED AHEAD OF IT EASTWARD. REGARDING
TUESDAY NIGHTS SHORTWAVE TROUGH...NOT IMPRESSED FOR PRECIPITATION.
ALTHOUGH DPVA FORCING IS PRETTY DECENT GIVEN THE TRACK...ISENTROPIC
LIFT IS VERY WEAK AT BEST AND MOSTLY CONFINED NORTH AND EAST OF OUR
FORECAST AREA. IN ADDITION...MOISTURE IS SERIOUSLY LACKING BETWEEN
850-650MB WHICH SHOULD BE ABLE TO ABSORB MOST OF THE SNOW BEING
PRODUCED ALOFT. WITH THE 02.12Z NAM/GFS/ECMWF ALL DRY...HAVE PULLED
PRECIPITATION CHANCES FOR TUESDAY EVENING...BUT DID LEAVE A MENTION
OF FLURRIES IN CASE ANYTHING CAN REACH THE GROUND. AFTER THIS...ONLY
ISSUES BECOME CLOUDS/TEMPERATURES WITH NO SYSTEMS EXPECTED TO COME
THROUGH TO PRODUCE PRECIPITATION. LOOKS LIKE THERE MAYBE SOME LOW
STRATUS IN THE WAKE OF THE TROUGH TUESDAY NIGHT...MAINLY OVER
WISCONSIN...WHICH SHOULD CLEAR OUT BY 12Z WEDNESDAY. OTHER BATCHES
OF MID/HIGH CLOUD ARE POSSIBLE LATE WEDNESDAY INTO THURSDAY
MORNING...MOSTLY ALONG AND EAST OF THE MISSISSIPPI RIVER...INDUCED
BY THE WARM ADVECTION PATTERN SET UP BY THE RISING 500MB HEIGHTS.
THEREFORE...WHEN IT COMES TO TEMPERATURES...BEST MIXING IS LIKELY TO
OCCUR WEST OF THE MISSISSIPPI RIVER. BIGGEST PROBLEM WHEN IT COMES
TO TEMPERATURES IS SEEING THE WARM ADVECTION AND HOW MUCH OF IT CAN
MIX DOWN. 850MB TEMPS CLIMB TO -2 TO +2C BY 00Z THURSDAY AND 7-11C
BY 00Z FRIDAY. WINDS ARE NOT FORECAST TO BE THAT STRONG...5 TO MAYBE
15 KT AT BEST WHICH HURTS MIXING...THOUGH THEY ARE OUT OF THE WEST
TO SOUTHWEST WHICH IS A GOOD DIRECTION. CERTAINLY SNOW FREE AREAS
COULD GET QUITE WARM FOR THIS TIME OF YEAR. FOR NOW HAVE FOLLOWED A
BLEND OF GUIDANCE FOR TEMPERATURES THROUGH THE TUESDAY NIGHT THROUGH
THURSDAY TIME PERIOD...BUT RAISED THEM UP A FEW DEGREES FOR HIGHS
OVER SNOW-FREE AREAS WEST OF THE MISSISSIPPI RIVER. NOTE...
THURSDAYS RECORD HIGH IS 47 AT LA CROSSE AND 45 AT ROCHESTER. THERE
IS POTENTIAL TO GET CLOSE TO THIS...ESPECIALLY IF WE ARE SUNNY ALL
DAY.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
257 PM CST MON JAN 2 2012
02.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE IN PRETTY GOOD
AGREEMENT AGAIN TODAY ON THE UPPER LEVEL AND SURFACE PATTERNS
HEADING INTO THE WEEKEND...AND REPRESENT SOLUTIONS SIMILAR TO THOSE
SEEN YESTERDAY. GENERAL THEME IS FOR THE WESTERN RIDGING SEEN
RECENTLY TO BRIEFLY BREAK DOWN AS A SHORTWAVE COMING OFF THE PACIFIC
DIGS DOWN TOWARDS THE FOUR CORNERS REGION ON SATURDAY. MEANWHILE...
DOWNSTREAM...THE SHORTWAVE TROUGH THAT WAS IN BRITISH COLUMBIA ON
THURSDAY IS FORECAST TO CROSS THE AREA FRIDAY NIGHT...PLACING THE
AREA IN TROUGHING FOR THE WEEKEND. NEW RIDGING IS THEN FORECAST TO
BUILD OVER THE WESTERN U.S. INTO THE NORTHERN PLAINS FOR SUNDAY
NIGHT INTO MONDAY...WHILE SHORTWAVES STREAM SOUTHEAST TOWARDS THE
UPPER GREAT LAKES ON THE EDGE OF THIS RIDGING.
OVERALL UPPER PATTERN IS UNFAVORABLE FOR MUCH IF ANY PRECIPITATION
AS MOISTURE IS VERY LIMITED. ANY MOISTURE IS TRAPPED BY THAT THE
SHORTWAVE DROPPING INTO THE FOUR CORNERS REGION...WHICH LOOKS TO
CROSS THE GULF COAST SUNDAY INTO MONDAY IN ADDITION...THERE
APPEARS TO BE A LACK OF SYSTEMS WITH MUCH FORCING. THEREFORE...A
DRY FORECAST CONTINUES THROUGH MONDAY.
TEMPERATURES REMAIN THE BIGGEST PROBLEM...ESPECIALLY GIVEN THE
UN-CLIMATOLOGICAL LACK OF SNOW ON THE GROUND OVER A LOT OF THE UPPER
MIDWEST. A COLD FRONT ASSOCIATED WITH THE SHORTWAVE TROUGH CROSSING
THE AREA FRIDAY NIGHT IS PROGGED TO MOVE THROUGH THE AREA FRIDAY
MORNING. ALTHOUGH 850MB TEMPS FALL THROUGH THE DAY...FROM 6-10C AT
12Z FRIDAY TO -2 TO +2C BY 00Z SATURDAY...THIS COOLING COMBINED WITH
MORE WIND COULD RESULT IN BETTER MIXING THAN THURSDAY. PLUS...WE
WILL START OFF WARMER ON FRIDAY. THEREFORE...FRIDAY SHOULD END UP
JUST AS WARM AS THURSDAY IF NOT WARMER. COOL DOWN THEN CONTINUES
INTO THE WEEKEND AS TROUGHING MOVES OVERHEAD...NOTED BY 850MB TEMPS
FALLING TO -5 TO -10C BY 00Z SUNDAY AND -7 TO -10C BY 00Z MONDAY.
THE COOL DOWN IS BRIEF...AS THE NEXT WARM UP ENSUES FOR MONDAY WITH
THE HEIGHT RISES ALOFT. FOR SATURDAY THROUGH MONDAY...FOLLOWED A
BLEND OF GUIDANCE FOR HIGHS AND LOWS.
&&
.AVIATION...THROUGH 06Z WEDNESDAY
1130 PM CST MON JAN 2 2012
BAND OF HIGH LEVEL CLOUDS WERE PUSHING SOUTHWARD ACROSS MINNESOTA
LATE THIS EVENING ON BACK SIDE OF THE SURFACE RIDGE. EXPECT RIDGE
AXIS TO PASS ACROSS THE TAF SITES BETWEEN 09Z-12Z AND ALLOW THESE
HIGH LEVEL CLOUDS TO PUSH INTO THE AREA. CEILINGS WILL REMAIN AOA
12K FEET. AS SURFACE RIDGE PUSHES EAST OF THE TAF SITES
TUESDAY...PRESSURE GRADIENT WILL TIGHTEN WITH SOUTH WINDS PICKING
UP BY LATE MORNING. WILL LIKELY SEE SOME GUSTS TO 20-23 KNOTS AT
KRST...WITH AROUND 12 TO 15 KNOTS AT KLSE. WINDS WILL DIMINISHING
SOMEWHAT AFTER 00Z WEDNESDAY...BUT STILL REMAIN ABOVE 12 KNOTS AT
KRST WITH JUST SOME SCATTERED HIGH CLOUDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
257 PM CST MON JAN 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1048 PM CST MON JAN 2 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT THROUGH TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW CYCLONIC FLOW
CONTINUING UNABATED OVER THE GREAT LAKES THIS AFTERNOON...WHILE HIGH
PRESSURE IS GRADUALLY SHIFTING EAST OVER THE GREAT PLAINS. PLENTY
OF LOW LEVEL MOISTURE...STEEP LOW LEVEL LAPSE RATES...AND MOISTURE
FLUXES OFF LAKE SUPERIOR ARE CONTRIBUTING TO SCATTERED FLURRIES AND
LIGHT SNOW SHOWERS OUTSIDE OF THE LAKE EFFECT SNOW BELT. SPEAKING
OF WHICH...1-3SM VISIBILITIES (WITH POCKETS OF LOWER VSBYS) IN SNOW
SHOWERS HAVE BEEN PREVAILING WITHIN THE SNOW BELT FOR MUCH OF THE
DAY. DRY AIR AS NOTED ON SATELLITE IMAGERY WITH DEWPOINTS SUB-ZERO
HAVE BEEN ERODING THE STREAMERS OVER WESTERN LAKE SUPERIOR AND ARE
STARTING TO APPROACH THE U.P. SHORELINE. WINDS HAVE BEEN THE
BREEZIEST OVER DOOR COUNTY WHERE HAVE SEEN A FEW GUSTS AROUND 39 KTS
AT SISTER BAY AND 35 KTS BY ALGOMA. WINTER WEATHER AND WIND
HEADLINES ARE THE MAIN FORECAST CONCERN IN THE SHORT TERM.
TONIGHT...SURFACE HIGH PRESSURE OVER THE GREAT PLAINS WILL SHIFT
EAST TO THE WESTERN GREAT LAKES BY MORNING. AS THE RIDGE AXIS
APPROACHES FROM THE WEST...STRONG MID-LEVEL SUBSIDENCE AND LOW LEVEL
DRY AIR BROUGHT IN BY NORTH WINDS WILL SHUT DOWN THE LAKE EFFECT
PROCESSES OVER WESTERN LAKE SUPERIOR...WHICH WILL CUT OFF THE
MOISTURE TRANSPORT FARTHER SOUTH AND EAST. AS A RESULT...WILL SEE
CLEARING SKIES THIS EVENING EVEN OVER THE SNOW BELT WHERE LAKE
EFFECT STREAMERS WILL BECOME INCREASINGLY CONFINED TO THE U.P.
BORDER. WILL LEAVE A SCATTERED MENTION OF SNOW SHOWERS THROUGH
MID-EVENING. WILL WAIT UNTIL THE LAST MINUTE TO DECIDE PULL THE
WINTER STORM WARNING...AS IT DEPENDS ON VISIBILITIES AND THE DEGREE
OF EROSION OF THE LAKE EFFECT BANDS FROM THE DRY AIR. WIND
HEADLINES ARE ALSO PROBLEMATIC AS ONLY THE TIP OF THE DOOR HAS BEEN
APPROACHING WIND ADVISORY CRITERIA. WINDS SHOULD ONLY GRADUALLY
SUBSIDE THIS EVENING...SO ALSO THINK MAY BE ABLE TO PULL THE
ADVISORY HEADLINE AT PRESS ISSUANCE. ANOTHER LAST MINUTE DECISION
ON THAT ONE. WINDS WILL BE DECOUPLING OVER CENTRAL AND NORTHERN
WISCONSIN AFTER MIDNIGHT. WITH THE FRESH SNOW PACK...TEMPS SHOULD
PLUMMET LATE TO SOME OF THE COLDEST READINGS OF THE SEASON. BUT
BECAUSE WINDS WILL BE DECOUPLING...WIND CHILL READINGS WILL ONLY
FALL TO 20 BELOW...WHICH FALLS JUST SHORT OF HEADLINES.
TUESDAY...SURFACE HIGH PRESSURE WILL MOVE EAST OF THE AREA BY MIDDAY
IN RESPONSE TO SHORTWAVE ENERGY TRACKING OVER THE NORTHERN PLAINS
AND NORTHERN MISSISSIPPI VALLEY. WILL SEE MID AND HIGH CLOUDS MOVE
OVERHEAD DOWNSTREAM OF THE SHORTWAVE...BUT LOW LEVELS ARE WAY TO DRY
FOR PRECIP. AFTER A COLD START TO THE DAY...HIGH TEMPS WILL REBOUND
TO THE MID TEENS TO LOW 20S.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. NEXT SYSTEM TO
AFFECT THE FORECAST AREA TOWARD TUESDAY NIGHT MAKING LANDFALL ON
THE NORTHWEST US COAST TODAY. TREND OF THE LAST FEW MODEL RUNS
WITH THIS SYSTEM HAVE BEEN DRY DUE TO LIMITED MOISTURE WHILE
WORKING OVER THE ROCKIES...AND MOVING AT GOOD CLIP IN THE FAST
NORTHWEST FLOW. THIS FAIRLY DEEP SHARP WAVE TROUGH WITH SURFACE
TROUGH REFLECTION HAS A NICE PERIOD OF WAA TUESDAY NIGHT...BUT
AVAILABLE LIFT AND MOISTURE WILL MAINLY SERVE TO SATURATE THE AIR
MASS...AND THE BEST SNOW GROWTH REGION PASSES QUICKLY OVER. DUE TO
CONSISTENT MODEL TO MODEL GUIDANCE OF NO MEASUREABLE QPF...WILL
LOWER POPS BUT KEEP A NON MEASURABLE PCPN MENTION GOING.
FOR THE REMAINDER OF THE WORK WEEK...THE WESTERN STATES UPPER
RIDGE FLATTENS WHILE A SYSTEM PASSES OVER SOUTHERN CANADA. A
PERIOD OF WAA WILL RAISE TEMPS ABOVE NORMAL LEVELS THIS WEEK UNTIL
A COLD FRONT DROPS OVER LATE IN THE WEEK FOR A RETURN TO MORE
NORMAL TEMPERATURES. NORTHWEST FLOW PROVIDES A MINOR LES SNOW
CHANCE FOR THE FAR NORTH CENTRAL WISCONSIN FRIDAY NIGHT INTO
SATURDAY.
ANOTHER NORTHERN STREAM SHORT WAVE TROUGH WITH FRONTAL SYSTEM
BRUSHES THE NORTHERN GREAT LAKES REGION TOWARD MONDAY...OTHERWISE
THE MEDIUM RANGE MODELS INDICATE NO SIGNIFICANT SYSTEMS TO AFFECT
THE AREA THROUGH EARLY NEXT WEEK.
&&
.AVIATION...VFR CONDITIONS NOW IN PLACE WITH RIDGE AXIS CROSSING
THE RGN. THEY SHOULD CONT INTO TOMORROW. EXPECT LLWS TO DEVELOP
TOMORROW AFTN AS WAA OCCURS OVER THE COLD DOME NR THE SFC.
SKOWRONSKI
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
601 PM CST MON JAN 2 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT THROUGH TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW CYCLONIC FLOW
CONTINUING UNABATED OVER THE GREAT LAKES THIS AFTERNOON...WHILE HIGH
PRESSURE IS GRADUALLY SHIFTING EAST OVER THE GREAT PLAINS. PLENTY
OF LOW LEVEL MOISTURE...STEEP LOW LEVEL LAPSE RATES...AND MOISTURE
FLUXES OFF LAKE SUPERIOR ARE CONTRIBUTING TO SCATTERED FLURRIES AND
LIGHT SNOW SHOWERS OUTSIDE OF THE LAKE EFFECT SNOW BELT. SPEAKING
OF WHICH...1-3SM VISIBILITIES (WITH POCKETS OF LOWER VSBYS) IN SNOW
SHOWERS HAVE BEEN PREVAILING WITHIN THE SNOW BELT FOR MUCH OF THE
DAY. DRY AIR AS NOTED ON SATELLITE IMAGERY WITH DEWPOINTS SUB-ZERO
HAVE BEEN ERODING THE STREAMERS OVER WESTERN LAKE SUPERIOR AND ARE
STARTING TO APPROACH THE U.P. SHORELINE. WINDS HAVE BEEN THE
BREEZIEST OVER DOOR COUNTY WHERE HAVE SEEN A FEW GUSTS AROUND 39 KTS
AT SISTER BAY AND 35 KTS BY ALGOMA. WINTER WEATHER AND WIND
HEADLINES ARE THE MAIN FORECAST CONCERN IN THE SHORT TERM.
TONIGHT...SURFACE HIGH PRESSURE OVER THE GREAT PLAINS WILL SHIFT
EAST TO THE WESTERN GREAT LAKES BY MORNING. AS THE RIDGE AXIS
APPROACHES FROM THE WEST...STRONG MID-LEVEL SUBSIDENCE AND LOW LEVEL
DRY AIR BROUGHT IN BY NORTH WINDS WILL SHUT DOWN THE LAKE EFFECT
PROCESSES OVER WESTERN LAKE SUPERIOR...WHICH WILL CUT OFF THE
MOISTURE TRANSPORT FARTHER SOUTH AND EAST. AS A RESULT...WILL SEE
CLEARING SKIES THIS EVENING EVEN OVER THE SNOW BELT WHERE LAKE
EFFECT STREAMERS WILL BECOME INCREASINGLY CONFINED TO THE U.P.
BORDER. WILL LEAVE A SCATTERED MENTION OF SNOW SHOWERS THROUGH
MID-EVENING. WILL WAIT UNTIL THE LAST MINUTE TO DECIDE PULL THE
WINTER STORM WARNING...AS IT DEPENDS ON VISIBILITIES AND THE DEGREE
OF EROSION OF THE LAKE EFFECT BANDS FROM THE DRY AIR. WIND
HEADLINES ARE ALSO PROBLEMATIC AS ONLY THE TIP OF THE DOOR HAS BEEN
APPROACHING WIND ADVISORY CRITERIA. WINDS SHOULD ONLY GRADUALLY
SUBSIDE THIS EVENING...SO ALSO THINK MAY BE ABLE TO PULL THE
ADVISORY HEADLINE AT PRESS ISSUANCE. ANOTHER LAST MINUTE DECISION
ON THAT ONE. WINDS WILL BE DECOUPLING OVER CENTRAL AND NORTHERN
WISCONSIN AFTER MIDNIGHT. WITH THE FRESH SNOW PACK...TEMPS SHOULD
PLUMMET LATE TO SOME OF THE COLDEST READINGS OF THE SEASON. BUT
BECAUSE WINDS WILL BE DECOUPLING...WIND CHILL READINGS WILL ONLY
FALL TO 20 BELOW...WHICH FALLS JUST SHORT OF HEADLINES.
TUESDAY...SURFACE HIGH PRESSURE WILL MOVE EAST OF THE AREA BY MIDDAY
IN RESPONSE TO SHORTWAVE ENERGY TRACKING OVER THE NORTHERN PLAINS
AND NORTHERN MISSISSIPPI VALLEY. WILL SEE MID AND HIGH CLOUDS MOVE
OVERHEAD DOWNSTREAM OF THE SHORTWAVE...BUT LOW LEVELS ARE WAY TO DRY
FOR PRECIP. AFTER A COLD START TO THE DAY...HIGH TEMPS WILL REBOUND
TO THE MID TEENS TO LOW 20S.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. NEXT SYSTEM TO
AFFECT THE FORECAST AREA TOWARD TUESDAY NIGHT MAKING LANDFALL ON
THE NORTHWEST US COAST TODAY. TREND OF THE LAST FEW MODEL RUNS
WITH THIS SYSTEM HAVE BEEN DRY DUE TO LIMITED MOISTURE WHILE
WORKING OVER THE ROCKIES...AND MOVING AT GOOD CLIP IN THE FAST
NORTHWEST FLOW. THIS FAIRLY DEEP SHARP WAVE TROUGH WITH SURFACE
TROUGH REFLECTION HAS A NICE PERIOD OF WAA TUESDAY NIGHT...BUT
AVAILABLE LIFT AND MOISTURE WILL MAINLY SERVE TO SATURATE THE AIR
MASS...AND THE BEST SNOW GROWTH REGION PASSES QUICKLY OVER. DUE TO
CONSISTENT MODEL TO MODEL GUIDANCE OF NO MEASUREABLE QPF...WILL
LOWER POPS BUT KEEP A NON MEASURABLE PCPN MENTION GOING.
FOR THE REMAINDER OF THE WORK WEEK...THE WESTERN STATES UPPER
RIDGE FLATTENS WHILE A SYSTEM PASSES OVER SOUTHERN CANADA. A
PERIOD OF WAA WILL RAISE TEMPS ABOVE NORMAL LEVELS THIS WEEK UNTIL
A COLD FRONT DROPS OVER LATE IN THE WEEK FOR A RETURN TO MORE
NORMAL TEMPERATURES. NORTHWEST FLOW PROVIDES A MINOR LES SNOW
CHANCE FOR THE FAR NORTH CENTRAL WISCONSIN FRIDAY NIGHT INTO
SATURDAY.
ANOTHER NORTHERN STREAM SHORT WAVE TROUGH WITH FRONTAL SYSTEM
BRUSHES THE NORTHERN GREAT LAKES REGION TOWARD MONDAY...OTHERWISE
THE MEDIUM RANGE MODELS INDICATE NO SIGNIFICANT SYSTEMS TO AFFECT
THE AREA THROUGH EARLY NEXT WEEK.
&&
.AVIATION...SCT MVFR CONDITIONS WL LINGER FOR A TIME THIS
EVENING...THEN VFR CONDITIONS EXPECTED AS SFC RIDGE BUILDS IN.
SKOWRONSKI
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
530 PM CST MON JAN 2 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
257 PM CST MON JAN 2 2012
MAIN FORECAST CONCERNS ARE CLOUD COVER AND TEMPERATURES...ALONG WITH
WHETHER PRECIPITATION CAN OCCUR TUESDAY NIGHT.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED A SHORTWAVE TROUGH OVER THE PACIFIC NORTHWEST...RIDGING FROM
THE SOUTHWEST U.S. NORTHWARD INTO SASKATCHEWAN...AND DEEP TROUGHING
FROM SOUTHEAST CANADA SOUTHWARD INTO THE SOUTHEAST U.S.. COLD AIR
ASSOCIATED WITH THIS DEEP TROUGH IS FIRMLY ENTRENCHED OVER THE
FORECAST AREA...WITH 850MB TEMPS PER 12Z RAOBS AROUND -18C. GRB
SOUNDING REFLECTS THE COLD ADVECTION SEEN AS WELL...NOTED BY 24 HOUR
TEMPERATURE DROP OF 10-15C FROM THE SURFACE TO 400MB. TROPOPAUSE HAS
ALSO BEEN LOWERED TO 425MB. CLOUD COVER...RELATED TO MOISTURE STUCK
BELOW THE COLD FRONTAL INVERSION NEAR 800MB PER 12Z GRB/MPX
SOUNDINGS...HAS BEEN SLOWLY DISSIPATING DUE TO A COMBINATION OF
DAYTIME MIXING AND DRY AIR ADVECTING SOUTH OUT OF NORTHERN ONTARIO.
TO THE WEST...A RIDGE OF HIGH PRESSURE WAS LOCATED OVER THE EASTERN
DAKOTAS. FURTHER WEST...WARM ADVECTION IS TAKING PLACE ALONG THE LEE
OF THE ROCKIES...NOTED BY 12Z SOUNDINGS FROM GGW AND UNR WITH 850MB
TEMPS AROUND 0C. CIRRUS HAS BEEN PRESENT IN THESE AREAS TOO...COMING
FROM PACIFIC MOISTURE TOPPING THE UPPER RIDGING THERE.
TONIGHT AND TUESDAY...UPPER RIDGE SEEN OVER MONTANA INTO
SASKATCHEWAN IS PROGGED TO PUSH EAST DURING THIS PERIOD...IN
RESPONSE TO THE SHORTWAVE TROUGH OVER THE PACIFIC NORTHWEST MOVING
INTO WESTERN MINNESOTA BY 00Z WEDNESDAY. THE UPPER RIDGE AXIS SHOULD
CROSS THE FORECAST AREA MID-DAY TUESDAY. WITH THE UPPER RIDGING
BUILDING IN PROVIDING PLENTY OF SUBSIDENCE...NO PRECIPITATION IS
ANTICIPATED. EVEN AFTER THE UPPER RIDGE PASSES LATE TUESDAY AND
500MB HEIGHTS BEGIN TO FALL...THE PRESENCE OF SO MUCH DRY AIR
BROUGHT IN BY THE CURRENT UPPER TROUGH WILL KEEP THINGS DRY AND ANY
WARM ADVECTION CLOUDS TO MID OR HIGH LEVEL. CONCERN TONIGHT IS HOW
LOW TEMPERATURES MAY END UP WITH CLEAR SKIES LIKELY AND THE SURFACE
RIDGE MOVING IN OVERNIGHT. WOULD NOT BE SURPRISED IF TYPICAL COLD
SITES NORTH OF I-94...WHERE MORE THAN A TRACE OF SNOW EXISTS ON THE
GROUND...DROP TO 5 TO 10 BELOW ZERO. MOST OF THE REST OF THE AREA
SHOULD SEE LOWS IN THE SINGLE DIGITS ABOVE ZERO...WITH OTHER TYPICAL
COLD SPOTS IN WISCONSIN DROPPING TO 0 TO 5 BELOW. INCREASING SOUTH
WINDS WILL BRING IN WARMER AIR FOR TUESDAY...CAUSING 850MB TEMPS TO
CLIMB TO -2 TO -6C BY 18Z. SOME OF THIS WARM AIR MAY BE CAPPED
OFF...HELPED TOO BY THE INCREASE IN MID AND HIGH CLOUDS LATER IN THE
DAY PREVENTING MIXING. THEREFORE...HIGHS ARE ONLY FORECAST IN THE
20S. A FEW SITES IN NORTHEAST IOWA COULD TOP 30...THOUGH...CLOSER TO
THE WARMEST AIR MOVING IN AND BEING SNOW-FREE.
TUESDAY NIGHT THROUGH THURSDAY...SHORTWAVE TROUGH OVER WESTERN
MINNESOTA IS WELL AGREED UPON TO MOVE SOUTHEAST ACROSS THE FORECAST
AREA TUESDAY NIGHT...WITH 500MB HEIGHTS SLOWLY BUILDING IN ITS WAKE
THROUGH THURSDAY. THE RISING HEIGHTS ARE IN RESPONSE TO A SHORTWAVE
TROUGH MOVING INTO BRITISH COLUMBIA AND THE PACIFIC NORTHWEST...
PUSHING RIDGING THAT DEVELOPED AHEAD OF IT EASTWARD. REGARDING
TUESDAY NIGHTS SHORTWAVE TROUGH...NOT IMPRESSED FOR PRECIPITATION.
ALTHOUGH DPVA FORCING IS PRETTY DECENT GIVEN THE TRACK...ISENTROPIC
LIFT IS VERY WEAK AT BEST AND MOSTLY CONFINED NORTH AND EAST OF OUR
FORECAST AREA. IN ADDITION...MOISTURE IS SERIOUSLY LACKING BETWEEN
850-650MB WHICH SHOULD BE ABLE TO ABSORB MOST OF THE SNOW BEING
PRODUCED ALOFT. WITH THE 02.12Z NAM/GFS/ECMWF ALL DRY...HAVE PULLED
PRECIPITATION CHANCES FOR TUESDAY EVENING...BUT DID LEAVE A MENTION
OF FLURRIES IN CASE ANYTHING CAN REACH THE GROUND. AFTER THIS...ONLY
ISSUES BECOME CLOUDS/TEMPERATURES WITH NO SYSTEMS EXPECTED TO COME
THROUGH TO PRODUCE PRECIPITATION. LOOKS LIKE THERE MAYBE SOME LOW
STRATUS IN THE WAKE OF THE TROUGH TUESDAY NIGHT...MAINLY OVER
WISCONSIN...WHICH SHOULD CLEAR OUT BY 12Z WEDNESDAY. OTHER BATCHES
OF MID/HIGH CLOUD ARE POSSIBLE LATE WEDNESDAY INTO THURSDAY
MORNING...MOSTLY ALONG AND EAST OF THE MISSISSIPPI RIVER...INDUCED
BY THE WARM ADVECTION PATTERN SET UP BY THE RISING 500MB HEIGHTS.
THEREFORE...WHEN IT COMES TO TEMPERATURES...BEST MIXING IS LIKELY TO
OCCUR WEST OF THE MISSISSIPPI RIVER. BIGGEST PROBLEM WHEN IT COMES
TO TEMPERATURES IS SEEING THE WARM ADVECTION AND HOW MUCH OF IT CAN
MIX DOWN. 850MB TEMPS CLIMB TO -2 TO +2C BY 00Z THURSDAY AND 7-11C
BY 00Z FRIDAY. WINDS ARE NOT FORECAST TO BE THAT STRONG...5 TO MAYBE
15 KT AT BEST WHICH HURTS MIXING...THOUGH THEY ARE OUT OF THE WEST
TO SOUTHWEST WHICH IS A GOOD DIRECTION. CERTAINLY SNOW FREE AREAS
COULD GET QUITE WARM FOR THIS TIME OF YEAR. FOR NOW HAVE FOLLOWED A
BLEND OF GUIDANCE FOR TEMPERATURES THROUGH THE TUESDAY NIGHT THROUGH
THURSDAY TIME PERIOD...BUT RAISED THEM UP A FEW DEGREES FOR HIGHS
OVER SNOW-FREE AREAS WEST OF THE MISSISSIPPI RIVER. NOTE...
THURSDAYS RECORD HIGH IS 47 AT LA CROSSE AND 45 AT ROCHESTER. THERE
IS POTENTIAL TO GET CLOSE TO THIS...ESPECIALLY IF WE ARE SUNNY ALL
DAY.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
257 PM CST MON JAN 2 2012
02.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE IN PRETTY GOOD
AGREEMENT AGAIN TODAY ON THE UPPER LEVEL AND SURFACE PATTERNS
HEADING INTO THE WEEKEND...AND REPRESENT SOLUTIONS SIMILAR TO THOSE
SEEN YESTERDAY. GENERAL THEME IS FOR THE WESTERN RIDGING SEEN
RECENTLY TO BRIEFLY BREAK DOWN AS A SHORTWAVE COMING OFF THE PACIFIC
DIGS DOWN TOWARDS THE FOUR CORNERS REGION ON SATURDAY. MEANWHILE...
DOWNSTREAM...THE SHORTWAVE TROUGH THAT WAS IN BRITISH COLUMBIA ON
THURSDAY IS FORECAST TO CROSS THE AREA FRIDAY NIGHT...PLACING THE
AREA IN TROUGHING FOR THE WEEKEND. NEW RIDGING IS THEN FORECAST TO
BUILD OVER THE WESTERN U.S. INTO THE NORTHERN PLAINS FOR SUNDAY
NIGHT INTO MONDAY...WHILE SHORTWAVES STREAM SOUTHEAST TOWARDS THE
UPPER GREAT LAKES ON THE EDGE OF THIS RIDGING.
OVERALL UPPER PATTERN IS UNFAVORABLE FOR MUCH IF ANY PRECIPITATION
AS MOISTURE IS VERY LIMITED. ANY MOISTURE IS TRAPPED BY THAT THE
SHORTWAVE DROPPING INTO THE FOUR CORNERS REGION...WHICH LOOKS TO
CROSS THE GULF COAST SUNDAY INTO MONDAY IN ADDITION...THERE
APPEARS TO BE A LACK OF SYSTEMS WITH MUCH FORCING. THEREFORE...A
DRY FORECAST CONTINUES THROUGH MONDAY.
TEMPERATURES REMAIN THE BIGGEST PROBLEM...ESPECIALLY GIVEN THE
UN-CLIMATOLOGICAL LACK OF SNOW ON THE GROUND OVER A LOT OF THE UPPER
MIDWEST. A COLD FRONT ASSOCIATED WITH THE SHORTWAVE TROUGH CROSSING
THE AREA FRIDAY NIGHT IS PROGGED TO MOVE THROUGH THE AREA FRIDAY
MORNING. ALTHOUGH 850MB TEMPS FALL THROUGH THE DAY...FROM 6-10C AT
12Z FRIDAY TO -2 TO +2C BY 00Z SATURDAY...THIS COOLING COMBINED WITH
MORE WIND COULD RESULT IN BETTER MIXING THAN THURSDAY. PLUS...WE
WILL START OFF WARMER ON FRIDAY. THEREFORE...FRIDAY SHOULD END UP
JUST AS WARM AS THURSDAY IF NOT WARMER. COOL DOWN THEN CONTINUES
INTO THE WEEKEND AS TROUGHING MOVES OVERHEAD...NOTED BY 850MB TEMPS
FALLING TO -5 TO -10C BY 00Z SUNDAY AND -7 TO -10C BY 00Z MONDAY.
THE COOL DOWN IS BRIEF...AS THE NEXT WARM UP ENSUES FOR MONDAY WITH
THE HEIGHT RISES ALOFT. FOR SATURDAY THROUGH MONDAY...FOLLOWED A
BLEND OF GUIDANCE FOR HIGHS AND LOWS.
&&
.AVIATION...TONIGHT AND TUESDAY
530 PM CST MON JAN 2 2012
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. SURFACE RIDGE
WILL WORK ITS WAY ACROSS THE AREA TONIGHT WITH PRESSURE GRADIENT
RELAXING AND WINDS DROPPING BELOW 10 KNOTS EARLY THIS EVENING. THE
RIDGE WILL SHIFT EAST OF THE TAF SITES ON TUESDAY WITH WINDS
SWITCHING TO THE SOUTH AHEAD OF AN APPROACHING TROUGH. WITH AN
INCREASING PRESSURE GRADIENT...SOUTHERLY WINDS WILL INCREASE TO
ABOVE 12 KNOTS AT KRST...BUT REMAIN AROUND 10 KNOTS AT KLSE. WITH
THE SOUTHERLY WINDS...SOME ID AND HIGH LEVEL CLOUDS WILL PASS
ACROSS THE AREA WITH A SCT-BKN DECK ABOVE 12K FEET.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
257 PM CST MON JAN 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
306 PM CST SUN JAN 1 2012
.SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
MOVING TO THE NORTHEAST OVER LAKE HURON THIS AFTERNOON WHILE HIGH
PRESSURE HAS SETTLED OVER THE FRONT RANGE OF THE ROCKIES. STRONG
SHORTWAVE OVER SOUTHERN WISCONSIN IS CONTRIBUTING TO WIDESPREAD SNOW
SHOWERS AND FLURRIES ACROSS THE REGION...BUT THE SNOW SHOWERS EXIST
ALL THE WAY BACK TO NORTHERN MINNESOTA AND SW ONTARIO. LAKE EFFECT
SNOWS REMAIN NORTH OF THE U.P. BORDER SO FAR...BUT WITH SOME
IMPRESSIVE BANDS ON THE MQT RADAR. MEANWHILE...WIND GUSTS THIS
AFTERNOON HAVE REMAINED WELL BELOW ADVISORY CRITERIA SO FAR. HAVE
HAD A FEW GUSTS IN THE 34-37 KT RANGE OVER CENTRAL WISCONSIN LATE
THIS MORNING...BUT HAVE SINCE DIMINISHED. HEADLINES AND SNOW
AMOUNTS REMAIN THE MAIN FORECAST CONCERN IN THE SHORT TERM.
TONIGHT...LOW PRESSURE WILL EXIT THE REGION INTO QUEBEC WHILE ARCTIC
HIGH PRESSURE MOVES EAST OVER THE GREAT PLAINS. A TIGHT PRESSURE
GRADIENT WILL REMAIN IN PLACE BETWEEN THESE TWO FEATURES WITH 0-1KM
AGL WIND SPEEDS AROUND 35 KTS. DESPITE THE COLD ADVECTION
TODAY...WIND GUSTS HAVE BEHAVED AND HAVE ONLY BRIEFLY APPROACHED
ADVISORY CRITERIA OVER CENTRAL WISCONSIN. WILL MONITOR WIND GUSTS
UNTIL THE LAST MINUTE BEFORE MAKING HEADLINE DECISIONS ON THE WIND
ADVISORY. AFTER COORDINATION...WILL LEAVE WIND HEADLINES IN PLACE
AS A TIGHT PRESSURE GRADIENT UPSTREAM AND COLD ADVECTION CONTINUES.
STILL PLENTY GOING ON BESIDES THE GUSTY WINDS. SHORTWAVE TROUGH
NEAR MSN WILL BE EXITING OVER SOUTHERN LAKE MICHIGAN DURING THE
EVENING. ANOTHER SHEARED WAVE OVER LAKE WINNIPEG WILL DIVE
SOUTHEAST OVER THE NORTHERN MISSISSIPPI VALLEY TONIGHT AND KEEP WEAK
QG FORCING IN PLACE. COMBINED WITH 1-3SM SNOW OBS ALL THE WAY NORTH
OF INTERNATIONAL FALLS AND SATURATION OF THE COLUMN ABOVE THE -10C
LINE IN PROGGED SOUNDINGS...WILL LEAVE A SCATTERED SNOW SHOWER
MENTION ACROSS THE FORECAST AREA FOR THE DURATION OF THE EVENING.
THE BIGGEST IMPACT WILL BE THE LAKE EFFECT SNOW OVER NORTH-CENTRAL
WISCONSIN. CONDITIONS WILL BE IMPROVING FOR SIGNIFICANT
ACCUMULATIONS THROUGH THE NIGHT. MAY NOT BE A WHOLE LOT OF IMPACT
THIS EVENING...AS WIND DIRECTIONS OF 320-330 ARE NOT CONDUCIVE FOR
ACCUMS EXCEPT ALONG THE U.P. BORDER. BUT TRAJECTORIES WILL VEER
SLIGHTLY TO 340 DEGREES BY 12Z MONDAY. WITH DELTA T/S IN THE UPPER
TEENS AND 850-700MB MOISTURE OF 80 PCT...SHOULD SEE GOOD DENDRITIC
SNOW GROWTH TO GENERATE A HALF INCH TO ONE INCH PER HOUR SNOWFALL
RATES BY THIS TIME. WILL LOWER SNOW AMOUNTS IN THE EVENING...BUT
KEEP THEM AROUND 2-3 INCHES DURING THE OVERNIGHT PERIOD. THIS WILL
YIELD 3-5 INCH AMOUNTS...HIGHEST OVER THE NORTHERN PART OF VILAS
COUNTY.
MONDAY...THE LAKE EFFECT SHOW WILL CONTINUE OVER N-C WISCONSIN
DURING THE MORNING. BUT CONDITIONS WILL TURN INCREASINGLY HOSTILE
DURING THE 15-18Z TIMEFRAME AS DRY ARCTIC AIR FLOWS OVER WESTERN
LAKE SUPERIOR. AS A RESULT...SNOWFALL RATES SHOULD BE DIMINISHING
BY MIDDAY AND THROUGH THE AFTERNOON...AS THE DRY AIR SURGES
SOUTHEAST. WILL GO WITH AN ADDITIONAL 2-4 INCHES IN THE FORECAST.
CLOUDY TO MOSTLY CLOUDY CONDITIONS WILL EXIST ELSEWHERE. LEFT AN
ISOLATED FLURRY MENTION GOING FOR THE MORNING BEFORE THE DRIER AIR
ARRIVES. SOME BREAKS IN THE CLOUDS ARE LIKELY MID TO LATE
AFTERNOON. HIGHS RANGING FROM THE LOWER TEENS TO LOWER 20S.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY.
SURFACE RIDGE WILL GRADUALLY DRIFT INTO THE FORECAST AREA MONDAY
NIGHT. SUBSTANTIAL DRYING AND STRONG SUBSIDENCE SHOULD PRETTY
MUCH PUT AN END TO ANY LAKE EFFECT SNOW FOR VILAS COUNTY BY EARLY
MONDAY EVENING. JUST KEPT A FEW LINGERING FLURRIES FOR FAR
NORTHERN VILAS BEFORE 06Z THEN DRY THERAFTER. STILL APPEARS MONDAY
NIGHT WILL BE THE COLDEST NIGHT WE HAVE SEEN THIS SEASON WITH MIN
TEMPS EASILY FALLING INTO THE MIDDLE NEGATIVE TEENS ACROSS
NORTHCENTRAL OVERNIGHT GIVEN FRESH SNOW COVER THAT WAS RECEIEIVED EARLY
SUNDAY.
SHORTWAVE DISTURBANCE THEN QUICKLY DIVES SOUTHEAST INTO THE
WESTERN GREAT LAKES BY 00Z WEDNESDAY. AFTER A SUNNY AND COLD
START...WARM ADVECTION AHEAD OF THIS SYSTEM WILL LIKELY BRING IN
SOME MID TO HIGH-LEVEL CLOUDS DURING THE DAY ON TUESDAY. GIVEN THE
COLD START AND INCREASING CLOUDS LATER IN THE DAY...MAX TEMPS WILL
LIKELY NOT BE ABLE RISE MUCH PAST THE MIDDLE TEENS. AS PER
PREVIOUS FORECAST...STILL APPEARS LOW CHANCE POPS ARE WARRANTED
FOR FOR AT LEAST THE NORTHERN HALF OF THE FORECAST AREA. APPEARS
SYSTEM MAY BE A BIT FASTER THAN PREVIOUS MODEL RUNS THUS FOCUSED
HIGHEST POPS IN THE 00Z TO 06Z TIME FRAME. PRECIP AMOUNTS APPEAR
MINIMAL WITH LIGHT SNOW OR SNOW SHOWERS PROVIDING LITTLE IF ANY
ACCUMULATION OVERNIGHT.
DURING THE LATER HALF OF THE WORK WEEK BROAD RIDGE OVER THE
WESTERN CONUS GRADUALLY FLATTENS AND BECOMES MORE ZONAL AS SEVERAL
PIECES OF ENERGY MOVE ONSHORE OVER THE WEST COAST OF THE U.S. THIS
SHOULD LEAD TO A GENERAL BENIGN PERIOD WITH TEMPERATURES AT OR
ABOVE NORMAL STARTING WEDNESDAY...AND MODERATING FURTHER TO NEAR
40 BY WEEKS END. FAIRLY LARGE DESCREPANCY IN THE MEDIUM RANGE
MODELS FOR FRIDAY INTO THE WEEKEND ON SYSTEM MOVING ACROSS
SOUTHERN CANADA. PREFER MUCH WEAKER AND MORE ZONAL-LOOKING
ECMWF/CANADIAN. THUS KEPT FORECAST MAINLY DRY AND LEANED SLIGHTLY
WARMER THAN MODEL BLEND ESPECIALLY FOR SATURDAY.
&&
.AVIATION...STRONG LOW PRESSURE WILL EXIT TOWARDS QUEBEC OVER THE
TAF PERIOD. HOWEVER...PLENTY OF LOW STRATUS AND LIGHT SNOW SHOWERS
UPSTREAM WHICH WILL PLAGUE THE TAF SITES THROUGH AT LEAST THIS
EVENING. SCATTERED SNOW SHOWERS WILL HANG AROUND LONGER AT RHI AS
THE LAKE EFFECT MACHINE CRANKS UP TONIGHT. MAY SEE CIGS REACH LOW
END VFR TONIGHT BASED ON OBS UPSTREAM...BUT PLAYED IT CONSERVATIVE
AND STAYED WITH HIGH END MVFR. PARTIAL CLEARING LOOKS TO OCCUR
MONDAY AFTERNOON. WINDS WILL REMAIN GUSTY THROUGH THE TAF
PERIOD...WITH A FEW GUSTS UP TO 35-40KTS. WIND GUSTS WILL PROBABLY
SETTLE DOWN FOR A PERIOD TONIGHT.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ010>013-018>021-
030-031-035>040-045-048>050-073-074.
WIND ADVISORY UNTIL 6 PM CST MONDAY FOR WIZ022.
WINTER STORM WARNING UNTIL 3 PM CST MONDAY FOR WIZ005.
&&
$$
MPC/ESB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
304 PM CST SUN JAN 1 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
304 PM CST SUN JAN 1 2012
MAIN FORECAST CONCERNS ARE WINDS THIS EVENING AND PRECIPITATION
CHANCES TONIGHT AS WELL AS TUESDAY EVENING.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO SOUTHWEST CANADA...AND
TROUGHING FROM HUDSON BAY SOUTH INTO THE OHIO VALLEY. WITHIN THIS
TROUGH...THE MOST IMPORTANT SHORTWAVES/PV ANOMALIES OF NOTE INCLUDE
ONE OVER SOUTHERN WISCONSIN AND THE OTHER IN SOUTHERN MANITOBA.
NEITHER OF THESE FEATURES ARE PROVIDING MUCH LIFT...NOTED BY
850-700MB AND 500-300MB QG PLOTS. HOWEVER...THEY ARE HELPING TO
LOWER THE TROPOPAUSE AND STEEPEN UP THE LOW TO MID LEVEL LAPSE
RATES. THE LAPSE RATES ARE NOTED BY HAVING 850MB TEMPS AROUND -11C
AT MPX...INL AND BIS...WHICH ARE ADVECTING SOUTHEAST ON 40-60 KT
WINDS PER 12Z RAOBS. WITH STILL PLENTY OF MOISTURE LINGERING IN THE
WAKE OF LAST NIGHTS SYSTEM AND SURFACE TEMPERATURES IN THE MID TO
UPPER 20S F...SCATTERED TO NUMEROUS SNOW SHOWERS COVER MUCH OF
WISCONSIN AND MINNESOTA. THE STEEP LAPSE RATES AND A TIGHT SURFACE
PRESSURE GRADIENT OVER THE FORECAST AREA IS ALSO LEADING TO WINDY
CONDITIONS. FOR THE MOST PART...WIND GUSTS HAVE STAYED BETWEEN 35
AND 50 MPH...STRONGEST SOUTH OF I-90 WHERE SOME SUN OCCURRED
EARLIER TODAY. FOR LOOKING AHEAD TO WHEN SKIES MIGHT CLEAR...BACK
EDGE OF THE STRATUS IS OVER THE FAR EASTERN DAKOTAS...WELL EAST OF
A 1039MB SURFACE HIGH LOCATED OVER EASTERN MONTANA.
TONIGHT AND MONDAY...SHORTWAVE/PV ANOMALY OVER SOUTHERN MANITOBA IS
FORECAST TO DROP SOUTHEAST INTO THE FORECAST AREA AFTER MIDNIGHT
TONIGHT. AGAIN...THIS FEATURE DOES NOT LOOK LIKE IT WILL PROVIDE
MUCH LIFT. HOWEVER...COLDER AIR ASSOCIATED WITH IT...NOTED BY 850MB
TEMPS FALLING TO -16 TO -18C BY 12Z MONDAY...SHOULD HELP TO KEEP THE
LOW LEVEL LAPSE RATES STEEP AND PROVIDE THE OPPORTUNITY FOR AT LEAST
SOME FLURRIES OUT OF THE STRATUS. SINCE THE LAPSE RATES REMAIN STEEP
AND THE PRESSURE GRADIENT REALLY DOES NOT RELAX THAT MUCH FROM
TODAY...EXPECTING GUSTS TO AT LEAST STAY UP IN WIND ADVISORY
CRITERIA THIS EVENING. LOSS OF DAYTIME HEATING MAY HINDER SOME OF
THE DOWNWARD TRANSPORT OF WINDS...SO HAVE NOT EXTENDED THE HAZARDS
BEYOND THE 06Z END TIME. CERTAINLY THE WINDS WILL NEED TO BE
MONITORED THROUGHOUT THE EVENING FOR POSSIBLE EXTENSION OF GOING
HAZARDS. WITH THE COLD ADVECTION...LOOK FOR TEMPERATURES TO CONTINUE
TO FALL THROUGH THE NIGHT...BOTTOMING OUT MOSTLY IN THE TEENS. 500MB
HEIGHT RISES ARE THEN PROGGED FOR MONDAY...ON THE ORDER OF 100-200
METERS BETWEEN 12-00Z...AS THE NORTHERN PART OF THE WESTERN NORTH
AMERICA RIDGING GETS PUSHED EAST. WITH SUCH STRONG SUBSIDENCE
ALOFT...NOT ANTICIPATING MUCH PRECIPITATION. IN FACT...WE SHOULD SEE
CLEARING OF THE STRATUS AS THE HIGH PRESSURE AREA IN EASTERN MONTANA
SHIFTS EAST INTO WESTERN MINNESOTA...BRINGING THE DRY AIR FROM
CANADA WITH AND AHEAD OF IT. 850MB TEMPS DO NOT WARM UP MUCH DURING
THE DAY MONDAY...ONLY TO -14 TO -16C. THEREFORE...MONDAY WILL LIKELY
BE THE COLDEST DAY WE HAVE SEEN IN AWHILE...AND ABOUT 5 DEGREES OR
SO BELOW NORMAL. A BLEND OF GUIDANCE SEEMS REASONABLE AT THIS TIME.
MONDAY NIGHT THROUGH WEDNESDAY...A SHORTWAVE TROUGH...CURRENTLY
SITTING OVER THE EAST PACIFIC...IS PROGGED TO MOVE INTO THE NORTHERN
PLAINS TUESDAY MORNING. THE TROUGH IS THEN WELL AGREED UPON TO DROP
SOUTHEAST ACROSS WISCONSIN TUESDAY EVENING...REPLACING THE BRIEF
PERIOD OF RIDGING THAT WILL HAVE BEEN IN PLACE OVER THE FORECAST
AREA ON TUESDAY. ALTHOUGH DPVA FORCING OCCURS ACROSS THE ENTIRE AREA
LATE TUESDAY INTO TUESDAY EVENING WITH THE SHORTWAVE TROUGH...MUCH
OF THE MOISTURE AND ISENTROPIC LIFT FORCING LOOKS TO STAY NORTH OF
THE FORECAST AREA. HAVE MAINTAINED SOME 20 PERCENT CHANCES FOR
TUESDAY EVENING ALONG AND NORTHEAST OF I-94...SINCE THERE IS SOME
WEAK ISENTROPIC LIFT IN THIS AREA THEN. OTHERWISE...THE ENTIRE TIME
PERIOD IS DOMINATED MOSTLY BY SUBSIDENCE...YIELDING DRY CONDITIONS.
THIS LEAVES CLOUD COVER AND TEMPERATURES THE ONLY CONCERNS. LEFTOVER
STRATUS FROM MONDAY SHOULD QUICKLY CLEAR IN THE EVENING AS THE
SURFACE HIGH MOVES IN. THIS SETS THE STAGE FOR A CHILLY NIGHT...
ESPECIALLY ACROSS WISCONSIN WHERE SNOWPACK EXISTS. BELOW ZERO
READINGS ARE LIKELY THERE. MID AND HIGH CLOUDS WILL THEN BE ON THE
INCREASE FOR TUESDAY AHEAD OF THE APPROACHING SHORTWAVE TROUGH. LOOK
FOR THESE TO CLEAR AFTER MIDNIGHT TUESDAY NIGHT...WITH A BRIEF
PERIOD OF POSSIBLE LOW STRATUS MOVING ACROSS WISCONSIN IN THE COLD
ADVECTION. THIS LOWER STRATUS LOOKS TO CLEAR WEDNESDAY
MORNING...WITH ONLY SOME HIGH CLOUDS POSSIBLE THEREAFTER. A GRADUAL
WARMING TREND IN TEMPERATURES IS FORECAST FOR TUESDAY AND
WEDNESDAY...RESULTING FROM 850MB TEMPS CLIMBING TO -4 TO -8C BY 00Z
WEDNESDAY AND 0 TO -4C BY 00Z THURSDAY. CERTIANLY SNOW FREE AREAS
SUCH AS NORTHEAST IOWA WILL HAVE AN EASIER TIME WARMING UP...WHICH
ALSO HAPPENS TO BE WHERE THE WARMEST 850MB AIR IS PROGGED. A BLEND
OF GUIDANCE STILL LOOKS REASONABLE FOR TEMPERATURES.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
304 PM CST SUN JAN 1 2012
01.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE GENERALLY IN GOOD
AGREEMENT THROUGH THE ENTIRE LONG TERM PERIOD. UPPER RIDGING THAT
HAS BEEN PRESENT OVER THE WESTERN U.S. IS STILL SHOWN TO FLATTEN OUT
AND PUSH EAST...IN RESPONSE TO A FAIRLY POTENT TROUGH COMING INTO
SOUTHWEST CANADA AROUND 00Z FRIDAY. THIS UPPER RIDGING WILL BRING
WITH IT 850MB TEMPS THAT ARE AROUND 2 STANDARD DEVIATIONS ABOVE
NORMAL INTO THE FORECAST AREA FRIDAY MORNING. THE SURFACE WARM FRONT
LEADING THE WARMER AIR LOOKS TO MOVE THROUGH THE AREA THURSDAY
NIGHT. MAY SEE SOME MID AND HIGH CLOUDS AHEAD OF THE WARM FRONT FOR
WEDNESDAY NIGHT AND THURSDAY...BUT NO PRECIPITATION IS ANTICIPATED
DUE TO PLENTY OF LOW LEVEL DRY AIR. COLD FRONT MOVES THROUGH DURING
THE DAY FRIDAY WITH LITTLE FANFARE. THE FRONT WILL BRING IN SOME
COOLER AIR...KNOCKING 850MB TEMPS DOWN FROM THE 8-10C READINGS AT
12Z FRIDAY TO PERHAPS AS COOL AS 2-6C BY 00Z SATURDAY. HOWEVER...THE
FRONT MAY ACTUALLY HELP TO PRODUCE BETTER MIXING. WITH MOSTLY SUNNY
SKIES ANTICIPATED ON FRIDAY...READINGS IN THE 40S ARE LIKELY WITH
50S CERTAINLY NOT OUT OF THE QUESTION. COLDEST READINGS EXPECTED
OVER NORTH CENTRAL WISCONSIN...WHILE WARMEST READINGS WOULD OCCUR
OVER NORTHEAST IOWA.
FOR NEXT WEEKEND...BROAD TROUGHING DEVELOPS FROM THE SOUTHWESTERN
U.S. INTO ONTARIO...WITH SOME INDICATIONS THAT IT MAY SPLIT INTO TWO
PIECES. MUCH OF THIS TROUGHING FORMS FROM THAT POTENT TROUGH...WHICH
IS DIGGING INTO THE NORTHERN PLAINS AND SOUTH CENTRAL CANADA ON
FRIDAY. THIS TROUGHING COMING INTO THE FORECAST AREA WILL ALLOW FOR
COLDER AIR TO MOVE INTO THE AREA. 850MB TEMPS ARE PROGGED TO DROP TO
-6 TO -10C BY 00Z SUNDAY AND AT LEAST -10 TO -14C BY 00Z MONDAY.
NOTE...THE 01.12Z ECMWF NOW SHOWS WARMER CONDITIONS...WITH 850MB
TEMPS ONLY DROPPING TO 0 TO -3C BY 00Z SUNDAY AND -4 TO -8C BY 00Z
MONDAY. THEREFORE...IT IS POSSIBLE THAT THE WEEKEND MIGHT BE A
LITTLE WARMER THAN FORECAST. DESPITE THE COOLING...NOT A LOT OF
MOISTURE LOOKS TO ACCOMPANYING THE TROUGH...SO DRY CONDITIONS ARE
FORECAST AT THIS TIME.
&&
.AVIATION...THROUGH 18Z MONDAY
1120 AM CST SUN JAN 1 2012
STRONG NORTHWEST WINDS AND SCATTERED SNOW SHOWERS WILL
PERSIST THROUGH LATE THIS AFTERNOON. PLAN ON MVFR TO VFR
CONDITIONS WITH CLOUD BASES IN THE 2000 TO 4000 FT RANGE. LOWER
CEILINGS AS THE SNOW SHOWER ACTIVITY MOVES THROUGH. MUCH OF THE
SNOW SHOWER ACTIVITY SHOULD OCCUR AT KLSE. IN ADDITION...VISIBILITIES
MAY BE REDUCED BRIEFLY TO AROUND 2 SM IN ANY SNOW SHOWERS THAT
DEVELOP. LOOK FOR NORTHWEST WINDS AT 20 TO 30 KTS...WITH GUSTS
RANGING FROM 35 TO 45 KTS. THE SNOW SHOWERS AND STRONG WINDS WILL
SUBSIDE THIS EVENING WITH MVFR/VFR CONDITIONS EXPECTED OVERNIGHT.
SCATTERED TO BROKEN STRATUS WILL LINGER ACROSS THE AREA OVERNIGHT
WITH CLOUD BASES OF 2500 TO 3500 FT. LOOK FOR WINDS TO FALL INTO
THE 15 TO 25 KT RANGE TONIGHT WITH GUSTS TO AROUND 30 KTS
POSSIBLE. THE STRATUS IS EXPECTED TO GRADUALLY CLEAR FROM WEST TO
EAST ACROSS THE AREA LATE MONDAY MORNING INTO MONDAY AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
304 PM CST SUN JAN 1 2012
WI...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ079-086>088-
094>096.
IA...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
925 AM EST TUE JAN 3 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
SNOW SHOWERS WILL END OVER NORTHEASTERN PORTIONS OF CENTRAL INDIANA
BY MIDDAY AS HIGH PRESSURE BUILDS INTO THE REGION. TEMPERATURES WILL
REMAIN COLD TODAY WITH MANY LOCATIONS REMAINING IN THE 20S. UPPER
LEVEL RIDGING WILL EXPAND INTO THE OHIO VALLEY DURING THE SECOND
HALF OF THE WEEK...BRINGING WARMER TEMPERATURES AND DRY CONDITIONS
THROUGH THE UPCOMING WEEKEND.
&&
.NEAR TERM /TODAY/...
SKIES HAVE BEEN CLEAR FOR MUCH OF THE OVERNIGHT ACROSS ALL BUT
NORTHEAST SECTIONS OF THE FORECAST AREA WHERE THE VEERING LOW LEVEL
FLOW HAS ENABLED EDGES OF THE LAKE EFFECT BANDS TO REACH DOWN INTO
AREAS EAST OF KOKOMO AND ANDERSON. WINDS HAVE STEADILY WEAKENED OVER
THE LAST SEVERAL HOURS WITH MAX GUSTS GENERALLY NO HIGHER THAN
20MPH. TEMPERATURES AT 08Z WERE IN THE TEENS AND LOWER 20S.
FOCUS REMAINS ON THE CONTINUATION OF SNOW SHOWERS AND FLURRIES OVER
NORTHEAST COUNTIES BEFORE FAVORABLE LOW LEVEL FLOW COLLAPSES BY
MIDDAY. HAVE RELIED ON HRRR AND RUC INITIALLY THIS MORNING WITH
RESPECT TO LOCATION OF SNOW BANDS.
RADAR MOSAIC OVER THE REGION HAS SHOWN A SLOW DECLINE IN SNOW BAND
INTENSITY ACROSS NORTHERN INDIANA AS BOUNDARY LAYER WINDS WEAKEN.
THIS TREND SHOULD CONTINUE THROUGH THE NEXT SEVERAL HOURS AS WIND
SPEEDS BETWEEN 925MB AND 800MB DROP TO 15-20MPH. THIS WILL MAKE IT
INCREASING MORE DIFFICULT FOR THE STEADIER BANDS TO MAKE IT INTO
NORTHEAST COUNTIES AND A NOTED DECREASE IN SNOWFALL INTENSITY AND
COVERAGE SHOULD OCCUR OVER THE NEXT 3-5 HOURS. AS THE MORNING
PROGRESSES...ARRIVAL OF THE HIGH PRESSURE RIDGE WILL FURTHER WEAKEN
LOW LEVEL FLOW WITH WINDS BACKING TO A MORE W/NW DIRECTION BY EARLY
AFTERNOON. WILL CARRY SCATTERED SNOW SHOWERS AND FLURRIES EAST OF A
KOKOMO-ANDERSON-NEW CASTLE LINE THROUGH MIDDAY WITH ANY LEFTOVER
FLURRIES SHIFTING NORTH OF THE FORECAST AREA THEREAFTER AS WINDS
BACK. ISOLATED ACCUMULATIONS OF A COUPLE TENTHS OF AN INCH CANNOT BE
RULED OUT EARLY THIS MORNING...ESPECIALLY OVER DELAWARE AND RANDOLPH
COUNTIES. WILL FRESHEN SPS TO HIGHLIGHT.
DRY WEATHER IS EXPECTED OVER THE REMAINDER OF THE FORECAST AREA WITH
THE EXPANSION OF SAID HIGH PRESSURE RIDGE INTO THE REGION. RUC/NAM
BOTH SUGGESTIVE OF SOME DIURNAL CU DEVELOPMENT THIS MORNING WITH LOW
LEVEL THERMAL TROUGH ALIGNED JUST EAST OF THE REGION. HOWEVER AS
WINDS BACK AND DRIER AIR ADVECTS INTO THE REGION FROM THE WEST
SHOULD SEE SKIES BECOME MAINLY SUNNY FOR THE AFTERNOON. EXCEPTION
WILL BE OVER NORTHEAST COUNTIES WHERE COLDEST BOUNDARY LAYER
CONDITIONS MAY ENABLE CLOUDS TO LINGER THROUGH MID AFTERNOON BEFORE
DIMINISHING.
TEMPS...DESPITE THE POTENTIAL FOR PLENTY OF SUNSHINE TODAY...WARM
ADVECTION DOES NOT REALLY COMMENCES UNTIL LATE DAY. COMBINED WITH
POOR MIXING LEVELS TO ONLY ABOUT 2KFT THIS AFTERNOON...MANY
LOCATIONS WILL BE HARD PRESSED TO CLIMB OUT OF THE 20S. TRENDED MUCH
CLOSER TO COOLER MAVMOS GUIDANCE.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON TEMPS AND CLOUDS IN AN OTHERWISE BENIGN
PERIOD. MODEL GUIDANCE IS SIMILAR ON MAIN FEATURES THROUGH THE SHORT
TERM AND HAVE TAKEN A BLEND.
SURFACE HIGH PRESSURE THROUGH THE PERIOD AND THE EXPANSION OF A
BROAD UPPER RIDGE BY THURSDAY INTO THE OHIO VALLEY WILL BOTH BE KEY
FEATURES IN KEEPING WEATHER DRY OVER CENTRAL INDIANA WITH A
TEMPERATURE RECOVERY BACK TO ABOVE NORMAL LEVELS BY THE END OF THE
PERIOD. TWO WEAK UPPER LEVEL DISTURBANCES WILL PASS NORTH OF THE
REGION EARLY WEDNESDAY MORNING AND AGAIN WEDNESDAY NIGHT. BOTH OF
THESE FEATURES WILL BRING A PERIOD OF INCREASED MID AND HIGH LEVEL
CLOUDINESS OVER MAINLY NORTHERN SECTIONS OF THE FORECAST AREA.
POTENTIAL FOR SOME STRATOCU DEVELOPMENT WEDNESDAY AS QUICK SHOT OF
COLD ADVECTION FOLLOWS IN WAKE OF THE INITIAL SHORTWAVE PASSAGE
ALOFT. THE EXPANSION OF THE UPPER RIDGE INTO THE REGION BY THURSDAY
WILL ENABLE A MORE SUBSTANTIAL PUSH OF MILDER AIR INTO CENTRAL
INDIANA ALONG WITH INCREASING SUNSHINE BY THURSDAY AFTERNOON. DRY
WEATHER WITH MOSTLY CLEAR SKIES WILL CONTINUE THURSDAY NIGHT AS MID
LEVEL HEIGHTS FURTHER RISE OVER THE REGION.
TEMPS...LOWS TONIGHT WILL BE REACHED DURING THE EVENING AS WARM
ADVECTION AHEAD OF THE INITIAL SHORTWAVE ENABLES STEADY OR SLOWLY
RISING TEMPS THROUGH THE 20S THE REMAINDER OF THE NIGHT. TRENDED
TOWARDS COOLER MET GUIDANCE WEDNESDAY AS POTENTIAL FOR STRATOCU
DEVELOPMENT MENTIONED ABOVE MAY STUNT TEMP RISES A BIT. LEANED
TOWARDS MAVMOS GUIDANCE THROUGH THE REMAINDER OF THE SHORT TERM WITH
HIGH TEMPERATURES CLIMBING INTO THE 40S THURSDAY AS LOW LEVEL
SOUTHWESTERLY FLOW PUMPS WARMER AIR INTO THE OHIO VALLEY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS ARE STILL SUPPORTING A DRY EXTENDED FORECAST. A LOW PRESSURE
SYSTEM AND ASSOCIATED COLD FRONT ARE STILL PROGGED TO MOVE ACROSS
THE GREAT LAKES REGION ON SATURDAY...BUT MOISTURE CONTINUES TO BE
LACKING. PLUS...THE ONLY GULF MOISTURE THAT WILL BE ADVECTED AHEAD
OF THE FRONT WILL BE AFTER IT/S THROUGH CENTRAL INDIANA. SO...REMOVED
MENTION OF POPS ACROSS THE SOUTHEAST QUADRANT OF FORECAST AREA ON
SATURDAY. BEYOND THAT...MODELS HAVE FALLEN OUT OF AGREEMENT IN
REGARD TO A LOW PRESSURE SYSTEM ON MONDAY AND TUESDAY.
ORIGINALLY...THEY BOTH INDICATED A TRACK ACROSS THE DEEP SOUTH.
HOWEVER...THE EURO IS PULLING IT MUCH FURTHER SOUTH NOW...WHILE THE
GFS IS SHOWING A VERY BROAD UPPER LEVEL TROUGH OVER MUCH OF THE OHIO
AND TENNESSEE VALLEYS...AND DOWN INTO THE DEEP SOUTH. AS A
RESULT...WILL NOT DEVIATE FROM DRY INITIALIZATION NUMBERS WITH THIS
MUCH INCONSISTENCY.
TEMPS...TRENDED FRIDAY/S HIGHS ON THE WARMER SIDE WITH DECENT
SOUTHWEST FLOW AHEAD OF AFOREMENTIONED COLD FRONT...AND BUMPED UP
FRIDAY NIGHT/S LOWS A FEW DEGREES AS WELL TO ACCOUNT FOR INCREASED
CLOUD COVER. OTHERWISE...STUCK WITH INITIALIZATION NUMBERS FOR THE
REMAINDER OF EXTENDED PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 03/15Z KIND TAF UPDATE/...
MINOR CHANGES MADE TO KIND TAF PER OBSERVATIONS. OTHERWISE...NO
OTHER CHANGES NEEDED AT THIS TIME.
PREVIOUS AVIATION DISCUSSION FOLLOWS...VFR CONDITIONS ARE EXPECTED
FOR ENTIRE TAF PERIOD AS HIGH PRESSURE BUILDS INTO TAF SITES. CLOUDS
AND ISOLATED FLURRIES WILL LINGER OVER NORTHEAST PORTIONS OF CENTRAL
INDIANA...BUT THEY WILL NOT AFFECT TAF SITES.
WINDS HAVE FINALLY TAPERED OFF AND WILL BE NORTHWESTERLY THROUGH
EARLY AFTERNOON...AND WILL THEN BACK TO THE SOUTHWEST LATE THIS
AFTERNOON AS HIGH PRESSURE MOVES CLOSER TO TAF SITES. SUSTAINED
SPEEDS WILL RANGE FROM 4 TO 9 KTS.
TONIGHT...CLOUDS WILL INCREASE IN THE MID AND HIGH LEVELS AS A
SYSTEM MOVES ACROSS ONTARIO AND THE GREAT LAKES
REGION...ESPECIALLY AT KLAF. HOWEVER...NO PRECIP IS EXPECTED.
SOUTHERLY WINDS WILL INCREASE EARLY TOMORROW MORNING AHEAD OF A
WEAK FRONTAL BOUNDARY...BUT NOWHERE NEAR AS BAD AS THE LAST FEW
DAYS. SUSTAINED SPEEDS WILL RANGE FROM 10 TO 14 KTS WITH SOME
GUSTS UP TO 24 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....TDUD
AVIATION...TDUD/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
649 AM EST TUE JAN 3 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
SNOW SHOWERS WILL END OVER NORTHEASTERN PORTIONS OF CENTRAL INDIANA
BY MIDDAY AS HIGH PRESSURE BUILDS INTO THE REGION. TEMPERATURES WILL
REMAIN COLD TODAY WITH MANY LOCATIONS REMAINING IN THE 20S. UPPER
LEVEL RIDGING WILL EXPAND INTO THE OHIO VALLEY DURING THE SECOND
HALF OF THE WEEK...BRINGING WARMER TEMPERATURES AND DRY CONDITIONS
THROUGH THE UPCOMING WEEKEND.
&&
.NEAR TERM /TODAY/...
SKIES HAVE BEEN CLEAR FOR MUCH OF THE OVERNIGHT ACROSS ALL BUT
NORTHEAST SECTIONS OF THE FORECAST AREA WHERE THE VEERING LOW LEVEL
FLOW HAS ENABLED EDGES OF THE LAKE EFFECT BANDS TO REACH DOWN INTO
AREAS EAST OF KOKOMO AND ANDERSON. WINDS HAVE STEADILY WEAKENED OVER
THE LAST SEVERAL HOURS WITH MAX GUSTS GENERALLY NO HIGHER THAN
20MPH. TEMPERATURES AT 08Z WERE IN THE TEENS AND LOWER 20S.
FOCUS REMAINS ON THE CONTINUATION OF SNOW SHOWERS AND FLURRIES OVER
NORTHEAST COUNTIES BEFORE FAVORABLE LOW LEVEL FLOW COLLAPSES BY
MIDDAY. HAVE RELIED ON HRRR AND RUC INITIALLY THIS MORNING WITH
RESPECT TO LOCATION OF SNOW BANDS.
RADAR MOSAIC OVER THE REGION HAS SHOWN A SLOW DECLINE IN SNOW BAND
INTENSITY ACROSS NORTHERN INDIANA AS BOUNDARY LAYER WINDS WEAKEN.
THIS TREND SHOULD CONTINUE THROUGH THE NEXT SEVERAL HOURS AS WIND
SPEEDS BETWEEN 925MB AND 800MB DROP TO 15-20MPH. THIS WILL MAKE IT
INCREASING MORE DIFFICULT FOR THE STEADIER BANDS TO MAKE IT INTO
NORTHEAST COUNTIES AND A NOTED DECREASE IN SNOWFALL INTENSITY AND
COVERAGE SHOULD OCCUR OVER THE NEXT 3-5 HOURS. AS THE MORNING
PROGRESSES...ARRIVAL OF THE HIGH PRESSURE RIDGE WILL FURTHER WEAKEN
LOW LEVEL FLOW WITH WINDS BACKING TO A MORE W/NW DIRECTION BY EARLY
AFTERNOON. WILL CARRY SCATTERED SNOW SHOWERS AND FLURRIES EAST OF A
KOKOMO-ANDERSON-NEW CASTLE LINE THROUGH MIDDAY WITH ANY LEFTOVER
FLURRIES SHIFTING NORTH OF THE FORECAST AREA THEREAFTER AS WINDS
BACK. ISOLATED ACCUMULATIONS OF A COUPLE TENTHS OF AN INCH CANNOT BE
RULED OUT EARLY THIS MORNING...ESPECIALLY OVER DELAWARE AND RANDOLPH
COUNTIES. WILL FRESHEN SPS TO HIGHLIGHT.
DRY WEATHER IS EXPECTED OVER THE REMAINDER OF THE FORECAST AREA WITH
THE EXPANSION OF SAID HIGH PRESSURE RIDGE INTO THE REGION. RUC/NAM
BOTH SUGGESTIVE OF SOME DIURNAL CU DEVELOPMENT THIS MORNING WITH LOW
LEVEL THERMAL TROUGH ALIGNED JUST EAST OF THE REGION. HOWEVER AS
WINDS BACK AND DRIER AIR ADVECTS INTO THE REGION FROM THE WEST
SHOULD SEE SKIES BECOME MAINLY SUNNY FOR THE AFTERNOON. EXCEPTION
WILL BE OVER NORTHEAST COUNTIES WHERE COLDEST BOUNDARY LAYER
CONDITIONS MAY ENABLE CLOUDS TO LINGER THROUGH MID AFTERNOON BEFORE
DIMINISHING.
TEMPS...DESPITE THE POTENTIAL FOR PLENTY OF SUNSHINE TODAY...WARM
ADVECTION DOES NOT REALLY COMMENCES UNTIL LATE DAY. COMBINED WITH
POOR MIXING LEVELS TO ONLY ABOUT 2KFT THIS AFTERNOON...MANY
LOCATIONS WILL BE HARD PRESSED TO CLIMB OUT OF THE 20S. TRENDED MUCH
CLOSER TO COOLER MAVMOS GUIDANCE.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON TEMPS AND CLOUDS IN AN OTHERWISE BENIGN
PERIOD. MODEL GUIDANCE IS SIMILAR ON MAIN FEATURES THROUGH THE SHORT
TERM AND HAVE TAKEN A BLEND.
SURFACE HIGH PRESSURE THROUGH THE PERIOD AND THE EXPANSION OF A
BROAD UPPER RIDGE BY THURSDAY INTO THE OHIO VALLEY WILL BOTH BE KEY
FEATURES IN KEEPING WEATHER DRY OVER CENTRAL INDIANA WITH A
TEMPERATURE RECOVERY BACK TO ABOVE NORMAL LEVELS BY THE END OF THE
PERIOD. TWO WEAK UPPER LEVEL DISTURBANCES WILL PASS NORTH OF THE
REGION EARLY WEDNESDAY MORNING AND AGAIN WEDNESDAY NIGHT. BOTH OF
THESE FEATURES WILL BRING A PERIOD OF INCREASED MID AND HIGH LEVEL
CLOUDINESS OVER MAINLY NORTHERN SECTIONS OF THE FORECAST AREA.
POTENTIAL FOR SOME STRATOCU DEVELOPMENT WEDNESDAY AS QUICK SHOT OF
COLD ADVECTION FOLLOWS IN WAKE OF THE INITIAL SHORTWAVE PASSAGE
ALOFT. THE EXPANSION OF THE UPPER RIDGE INTO THE REGION BY THURSDAY
WILL ENABLE A MORE SUBSTANTIAL PUSH OF MILDER AIR INTO CENTRAL
INDIANA ALONG WITH INCREASING SUNSHINE BY THURSDAY AFTERNOON. DRY
WEATHER WITH MOSTLY CLEAR SKIES WILL CONTINUE THURSDAY NIGHT AS MID
LEVEL HEIGHTS FURTHER RISE OVER THE REGION.
TEMPS...LOWS TONIGHT WILL BE REACHED DURING THE EVENING AS WARM
ADVECTION AHEAD OF THE INITIAL SHORTWAVE ENABLES STEADY OR SLOWLY
RISING TEMPS THROUGH THE 20S THE REMAINDER OF THE NIGHT. TRENDED
TOWARDS COOLER MET GUIDANCE WEDNESDAY AS POTENTIAL FOR STRATOCU
DEVELOPMENT MENTIONED ABOVE MAY STUNT TEMP RISES A BIT. LEANED
TOWARDS MAVMOS GUIDANCE THROUGH THE REMAINDER OF THE SHORT TERM WITH
HIGH TEMPERATURES CLIMBING INTO THE 40S THURSDAY AS LOW LEVEL
SOUTHWESTERLY FLOW PUMPS WARMER AIR INTO THE OHIO VALLEY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS ARE STILL SUPPORTING A DRY EXTENDED FORECAST. A LOW PRESSURE
SYSTEM AND ASSOCIATED COLD FRONT ARE STILL PROGGED TO MOVE ACROSS
THE GREAT LAKES REGION ON SATURDAY...BUT MOISTURE CONTINUES TO BE
LACKING. PLUS...THE ONLY GULF MOISTURE THAT WILL BE ADVECTED AHEAD
OF THE FRONT WILL BE AFTER IT/S THROUGH CENTRAL INDIANA. SO...REMOVED
MENTION OF POPS ACROSS THE SOUTHEAST QUADRANT OF FORECAST AREA ON
SATURDAY. BEYOND THAT...MODELS HAVE FALLEN OUT OF AGREEMENT IN
REGARD TO A LOW PRESSURE SYSTEM ON MONDAY AND TUESDAY.
ORIGINALLY...THEY BOTH INDICATED A TRACK ACROSS THE DEEP SOUTH.
HOWEVER...THE EURO IS PULLING IT MUCH FURTHER SOUTH NOW...WHILE THE
GFS IS SHOWING A VERY BROAD UPPER LEVEL TROUGH OVER MUCH OF THE OHIO
AND TENNESSEE VALLEYS...AND DOWN INTO THE DEEP SOUTH. AS A
RESULT...WILL NOT DEVIATE FROM DRY INITIALIZATION NUMBERS WITH THIS
MUCH INCONSISTENCY.
TEMPS...TRENDED FRIDAY/S HIGHS ON THE WARMER SIDE WITH DECENT
SOUTHWEST FLOW AHEAD OF AFOREMENTIONED COLD FRONT...AND BUMPED UP
FRIDAY NIGHT/S LOWS A FEW DEGREES AS WELL TO ACCOUNT FOR INCREASED
CLOUD COVER. OTHERWISE...STUCK WITH INITIALIZATION NUMBERS FOR THE
REMAINDER OF EXTENDED PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 03/12Z TAF ISSUANCE/...
VFR CONDITIONS ARE EXPECTED FOR ENTIRE TAF PERIOD AS HIGH PRESSURE
BUILDS INTO TAF SITES. CLOUDS AND ISOLATED FLURRIES WILL LINGER
OVER NORTHEAST PORTIONS OF CENTRAL INDIANA...BUT THEY WILL NOT
AFFECT TAF SITES.
WINDS HAVE FINALLY TAPERED OFF AND WILL BE NORTHWESTERLY THROUGH
EARLY AFTERNOON...AND WILL THEN BACK TO THE SOUTHWEST LATE THIS
AFTERNOON AS HIGH PRESSURE MOVES CLOSER TO TAF SITES. SUSTAINED
SPEEDS WILL RANGE FROM 4 TO 9 KTS.
TONIGHT...CLOUDS WILL INCREASE IN THE MID AND HIGH LEVELS AS A
SYSTEM MOVES ACROSS ONTARIO AND THE GREAT LAKES
REGION...ESPECIALLY AT KLAF. HOWEVER...NO PRECIP IS EXPECTED.
SOUTHERLY WINDS WILL INCREASE EARLY TOMORROW MORNING AHEAD OF A
WEAK FRONTAL BOUNDARY...BUT NOWHERE NEAR AS BAD AS THE LAST FEW
DAYS. SUSTAINED SPEEDS WILL RANGE FROM 10 TO 14 KTS WITH SOME
GUSTS UP TO 24 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....TDUD
AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
818 AM EST TUE JAN 3 2012
.SYNOPSIS...
COLD NORTHWEST WINDS ACROSS THE GREAT LAKES WILL BRING SNOW
SHOWERS THROUGH THIS AFTERNOON AND QUITE COLD TEMPERATURES THROUGH
TONIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
HAVE MADE ADJUSTMENTS TO SNOW BAND COVERAGE AND AMOUNTS BASED ON
BLEND OF RECENT HRRR AND NAM MODEL OUTPUT, THAT SHOWED LAKE EFFECT
SNOW BANDS MAY PERSIST ACROSS SOME PARTS OF WESTERN PENNSYLVANIA
AND EAST CENTRAL OHIO DUE TO TRAJECTORY OF NORTHWEST FLOW OFF THE
GREAT LAKES.
HAVE MAINTAINED HEADLINES AND WILL ISSUE SPECIAL WEATHER
STATEMENTS AS NEEDED FOR OTHER PERSISTING SNOW BANDS THAT DEVELOP.
NAM MODEL PROFILES SHOW CAPPING INVERSION LOWERING TO 5 KFT AGL TOWARD
EVENING WHICH SHOULD REDUCE ANY REMAINING SNOW SHOWERS TO LITTLE
MORE THAN FLURRIES.
TEMPERATURES WILL BE NEARLY STEADY TODAY AS COLD ADVECTION
CONTINUES. WINDS WILL BE GUSTY FORM THE NORTHWEST WITH WINDS
CHILLS IN THE SINGLE DIGITS. SURFACE RIDGE WILL BEGIN TO DAMPEN
SNOW SHOWERS THIS EVENING WITH TEMPERATURES IN THE TEENS TO SINGLE
DIGITS IN TH RIDGES. WIND CHILLS TONIGHT WILL BE BORDERLINE FOR AN
ADVISORY IN THE RIDGES AND WILL BE MONITORED.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
ON WEDNESDAY AND WEDNESDAY NIGHT...A SHORTWAVE TROUGH WILL
QUICKLY SWING SOUTHEAST ACROSS THE UPPER OH VALLEY BRINGING LOW
CHANCES FOR SNOW SHOWERS AS BEST DYNAMICS AND MOISTURE REMAIN
NORTH OF REGION. THURSDAY SHOULD BE MAINLY DRY AS A WEAK RIDGE
MOVES OVER THE REGION. TEMPERATURES WILL RECOVER WELL INTO THE 30S
THURSDAY AFTERNOON.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
LATEST MODELS SHOW CLIPPER MOVING ACROSS THE GREAT LAKES THURSDAY
NIGHT AND FRIDAY REMAINING FARTHER NORTH THAN PREVIOUS RUNS SO
HAVE GONE WITH A DRY FORECAST. WEAK FRONT WILL ARRIVE FRIDAY
NIGHT...WITH BEST CHANCE OF SHOWERS ON SATURDAY. SOME MODEL
DISAGREEMENT FOR SUNDAY INTO MONDAY...WITH DETERMINISTIC MODELS
INDICATING A CYCLONE DEVELOPING ACROSS THE SOUTHEASTERN UNITED
STATES (AND CLIPPING OUR SOUTHERN COUNTIES)...WHILE ENSEMBLES
GENERALLY KEEP CONDITIONS DRY. WITH MODELS STILL SHOWING SOME
INDICATION OF PRECIP...HAVE DECIDED TO KEEP SLIGHT CHANCE POPS FOR
THE SOUTHERN COUNTIES. HAVE ALSO ADDED SOME POPS NORTH FOR LAKE
EFFECT. TEMPERATURES SHOULD BE ABOVE NORMAL FRIDAY AND
SATURDAY...THEN MODERATING FOR SUNDAY AND MONDAY.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND RADAR DATA AND HRRR MODEL OUTPUT, EXPECT
LAKE EFFECT SNOW BANDS TO CAUSE FLIGHT CONDITIONS TO DETERIORATE
TO IFR AT TIMES INTO THE AFTERNOON. NORTHWEST SURFACE WINDS CAN
GUST TO 25 KTS.
NAM MODEL PROFILES THEN SHOW LOWERING INVERSION CAPPING LAKE
EFFECT INSTABILITY LATE AFTERNOON. HENCE EXPECT NO WORSE THAN MVFR
RESTRICTIONS THEN. EXPECT MAINLY VFR TONIGHT.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
LOW PRESSURE MOVING ACROSS THE GREAT LAKES COULD BRING SOME
RESTRICTIONS IN SNOW SHOWERS WEDNESDAY...BUT PRIMARILY NORTH OF
PITTSBURGH. VFR CONDITIONS ARE THEN EXPECTED AT ALL SITES THURSDAY
THROUGH FRIDAY NIGHT. A FRONT COULD BRING SOME SCATTERED
RESTRICTIONS IN SHOWERS ON SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR MDZ001.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ013>016-022-023-073-075.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR PAZ074-
076.
LAKE EFFECT SNOW WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ007>009.
WV...WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR WVZ023-
041.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1019 AM EST TUE JAN 3 2012
.SYNOPSIS...
ARCTIC AIRMASS REMAINS TODAY. WEAKER COLD FRONT MOVES THROUGH
WEDNESDAY. MODERATING TEMPERATURES FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
STUBBORN LAKE MICHIGAN-ENHANCED BAND OF SHSN CONTINUES TO LINGER
ACROSS THE SOUTHWEST HALF OF THE CWA. RUC SEEMS TO BE STRUGGLING
WITH THIS BAND BUT LOCAL HI-RES MODELS HAVE A BETTER HANDLE AND
LINGER THIS BAND AT LEAST INTO EARLY AFTERNOON BEFORE IT BEGINS TO
DISSIPATE. HAVE ALTERED POPS TO THIS THINKING. MEANWHILE...UPSLOPE
SHSN WILL ALSO CONTINUE IN THE MOUNTAINS. WILL LIKELY ALLOW
NON-MOUNTAIN PORTION OF ADVISORY TO EXPIRE AT NOON DUE TO THE
EXPECTED AFTERNOON DECREASING TREND...ALTHOUGH ANOTHER LOCALIZED
INCH OF ACCUMULATION IS POSSIBLE IN THE LAKE EFFECT BAND. 1-3
ADDITIONAL INCHES IS EXPECTED IN THE CENTRAL/NORTHERN MOUNTAIN
UPSLOPE ZONE. TEMPS GENERALLY GOOD AND ONLY MADE MINOR CHANGES.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ONE CLIPPER TYPE FEATURE TO CONTEND WITH WED AFTN/EVE...OTHERWISE
LOOKING FOR MODERATING TREND TOWARD END OF WEEK AS FLOW TURNS MORE
ZONAL. AFOREMENTIONED CLIPPER SWINGS THRU WITH LIMITED
LIFT/MOISTURE. COULD SEE A FEW SPRINKLES OR FLURRIES ACROSS THE
NORTH WITH PASSAGE...BUT ELECTED TO KEEP OUT OF WX ATTM. BEHIND
SYS...DID INSERT FLURRY MENTION ALONG AND EAST OF I79...BUMPING UP
POPS SOME ACROSS NORTHERN MTNS. VERY BRIEF WINDOW OF STOUT NW FLOW
/40KTS H85/...LESS THAN 6 HRS IN DURATION. MOISTURE/LIFT STAYS OUT
OF DENDRITIC GROWTH LAYER...REACHING SATURATION 8-10C WHICH IS
MARGINAL FOR CRYSTAL GROWTH. LIMITED ANY ACCUMULATION TO LESS THAN
AN INCH IN NORTHERN MTNS WED NIGHT. WITH A WELL MIXED
ATMOSPHERE...KEPT OVERNIGHT LOWS SOMEWHAT UNIFORM.
UPR TROF AXIS SHIFTS EAST ON THU WITH WAA COMMENCING AS UPR HEIGHTS
RECOVER. THIS WILL ALLOW SFC TEMPS TO MODERATE TO NEAR NORMAL ON THU
AMID ABUNDANT SUNSHINE...BEFORE CLIMBING ABV NORMAL FOR FRI. ELECTED
TO KEEP MTNS AND MTN VALLEYS ON COOL SIDE GIVEN SNOW COVER THOUGH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
AS HAS BEEN THE CASE FOR MUCH OF THIS WINTER...MODELS ARE IN STRONG
DISAGREEMENT...YES DISAGREEMENT...WITH HANDLING OF A SOUTHERN STREAM
SYSTEM IN THE SPLIT FLOW UPPER PATTERN FOR THE WEEKEND. INITIALLY...
HEIGHTS RISE SIGNIFICANTLY AND SURFACE HIGH PRESSURE SLIDE EAST FOR
THE END OF THE WORKWEEK...WHICH MEANS DRY WITH A SIGNIFICANT WARM UP
INTO THE 50S FRIDAY. MODELS ALSO AGREE ON A COLD FRONT PUSHING SOUTH
AND EAST OF OUR CWA (COUNTY WARNING AREA) LATER SATURDAY...WITH SOME
LIGHT RAIN AS TEMPERATURES WILL EASILY BE WARM ENOUGH IN THE
SOUTHERLY FLOW AHEAD OF THE FRONT.
THEREAFTER...THE BIG QUESTION IS WHAT HAPPENS TO A SOUTHERN PLAINS
UPPER LOW THAT EJECTS SATURDAY NIGHT AND SUNDAY. SOLUTIONS RANGE
FROM THE 12Z GFS BEING FLAT WITH IT AND TAKING IT WELL SOUTH OF US
AS NORTHERN STREAM BECOMES DOMINANT...TO THE 00Z ECMWF LIFTING A
WELL DEFINED SYSTEM TO THE MIDATLANTIC STATES AND OVERSPREADING AT
LEAST THE SOUTHEASTERN TWO THIRDS OF OUR CWA WITH PRECIP. OTHER
MODELS ARE SOMEWHERE IN BETWEEN. THUS...EVEN THO THE GFS IS VERY
INCONSISTENT RUN TO RUN...WE AND HPC HAVE TAKEN A COMPROMISE WHICH
STALLS THE FRONT SOUTH AND EAST OF US...ALLOWING WEAK WAVES OF LOW
PRESSURE TO MOVE ALONG THE FRONT AND AFFECT THE SOUTHEASTERN HALF OF
OUR CWA FOR LATER THIS WEEKEND INTO MONDAY. WILL KEEP THE NORTHWEST
HALF OF CWA DRY. FOR TEMPS...GIVEN THIS SOLUTION DOES NOT ALLOW
ENOUGH COLD AIR TO BE INGESTED INTO THE PRECIP SHIELD FOR
SNOW...UNTIL SUNDAY NIGHT AND MONDAY MAINLY OVER THE NORTHERN AND
CENTRAL MOUNTAINS. WILL KEEP PRECIP LIGHT IN ANY EVENT THIS WEEKEND
FOR NOW. LOOK FOR GENERALLY LOWER TO MID 40S LOW LANDS FOR HIGHS
THIS WEEKEND AND MID TO UPPER 30S FOR LOWS.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
STRATUS DECK WITH SNOW WILL CONTINUE THIS MORNING...WITH THE
LOWEST CEILINGS AND VISIBILITIES IN THE MOUNTAINS. DEEPER MOISTURE
PULLS OUT DURING THE MORNING...WHICH WILL CAUSE VISIBILITIES TO
IMPROVE SOME...ALTHOUGH LIGHT SNOW WILL CONTINUE DURING THE DAY.
SKIES WILL CLEAR TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE:MODERATE.
ALTERNATE SCENARIOS: EXPECT OBSERVATIONS TO BOUNCE IN AND OUT OF
SNOW SHOWERS.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY L L L L M M M M M M H H
HTS CONSISTENCY M M M M M M M H H H H H
BKW CONSISTENCY M M M M M M M M M M M M
EKN CONSISTENCY H M M M M M L L M M M M
PKB CONSISTENCY L L L L L M M M M M H H
CKB CONSISTENCY L M M L L L M M M M M M
AFTER 12Z WEDNESDAY...
NO IFR EXPECTED UNTIL POSSIBLY WEDNESDAY NIGHT IN THE MOUNTAINS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR WVZ015-016-
018-024>031-033-034.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
WVZ032-035>040-046-047.
OH...NONE.
KY...NONE.
VA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ003-004.
&&
$$
SYNOPSIS...JMV/RPY/30
NEAR TERM...CL
SHORT TERM...30
LONG TERM...JMV
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1038 AM EST TUE JAN 3 2012
.SYNOPSIS...
THE COLDEST AIR SO FAR THIS WINTER SEASON WILL CONTINUE TO SWEEP
SOUTHEAST ACROSS THE GREAT LAKES AND INTO PENNSYLVANIA TODAY THROUGH
WEDNESDAY. FREQUENT LAKE EFFECT SNOW SHOWERS AND SOME HEAVY SQUALLS
WILL BE CONCENTRATED ACROSS THE NORTHWESTERN MOUNTAINS AND LAUREL
HIGHLANDS. SNOW SHOWERS OF LESSER INTENSITY AND BRIEF SQUALLS WILL
DRIFT INTO THE NORTHERN AND CENTRAL MOUNTAINS AT TIMES. A WARMUP TO
ABOVE NORMAL TEMPERATURES IS EXPECTED LATER THIS WEEK BEFORE ANOTHER
SURGE OF COLD AIR APPROACHES FOR LATE IN THE UPCOMING WEEKEND. THE
COLD AIR...WESTERLY FLOW AND WARM LAKES COULD PRODUCE MORE LAKE
EFFECT SNOW ACROSS WESTERN PENNSYLVANIA NEXT MONDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL NOON TODAY/...
DOMINANT SNOWBAND WITH LAKE HURON CONNECTION CONTINUES TO WAGGLE
SW/NE OVER THE NORTHWEST MOUNTAINS AND LAUREL HIGHLANDS THIS
MORNING. THE BAND HAS WEAKENED EARLY THIS MORNING WITH
VISIBILITIES IN ONLY A FEW PLACES AS LOW AS 3/4 MILE AT THIS TIME.
LAPSE RATES REMAIN STEEP THROUGH THIS AFTERNOON AS THE COLDEST 850
MB AIR TRACKS ACROSS NORTHEAST PA WHILE A COMPACT SHORTWAVE TRACKS
THROUGH THE LAURELS AND INTO NO VA. THIS SHOULD KEEP SOME
ACCUMULATING SNOW GOING ACROSS THE LAURELS AND SNOWBELT REGION
THROUGH THIS EVENING...AND WILL MAKE NO CHANGES TO CURRENT
HEADLINES. WILL ALLOW WINTER WEATHER ADVISORY FOR PORTIONS OF THE
WEST CENTRAL MOUNTAINS AND NORTHERN MOUNTAINS TO EXPIRE ON TIME
AT 17Z AS CONDITIONS HAVE OVERALL IMPROVED FROM EARLIER TODAY.
HIGH RESOLUTION HRRR AND NAM12 INDICATE ORGANIZATION AND INTENSITY
OF SNOW BANDS DECREASING SIGNIFICANTLY AFTER 20Z...AS INVERSION
HEIGHTS START TO CRASH AND BOUNDARY LAYER TEMPS MODERATE. HOWEVER...
AS PREVIOUS SHIFT NOTED...NAM BUFKIT SHOWS A CROSS-HAIR SIGNATURE
OF STRONG UVVEL WITHIN THE FAVORABLE THERMAL RIBBON FOR DENDRITIC
SNOW GROWTH. THIS SHOULD BRING MOST AREAS OF CENTRAL PA ANOTHER
COATING TO ONE INCH OF SNOW...WITH A COUPLE INCHES OR MORE OF NEW
FLUFFY /WIND-WHIPPED SNOW FALLING ACROSS THE NW MTNS AND SNOWBELT
OF WARREN COUNTY.
CONTINUED DEEP-LAYER COLD ADVECTION WILL KEEP TEMPS STEADY OR SLOWLY
FALLING...IN THE TEENS TO LOWER 20S ACROSS THE CENTRAL AND WESTERN
COUNTIES...AND MID TO UPPER 20S IN THE SUSQ VALLEY. WIND CHILLS
WILL FREQUENTLY DIP BELOW ZERO TODAY ACROSS THE NRN AND WRN
MTNS...AND HOLD IN THE SINGLE DIGITS TO LOWER TEENS ELSEWHERE.
&&
.SHORT TERM /NOON TODAY THROUGH 6 PM WEDNESDAY/...
WARMER AIR ALOFT MOVES IN TONIGHT DIMINISHING THE SNOW SHOWERS
RATHER QUICKLY. STEEP LLVL LAPSE RATES...WILL COMBINE WITH BACKING
BLYR WINDS AND WEAK ISENTROPIC UPGLIDE WITHIN THE 275-285K THETA
CHANNEL TO MAINTAIN BKN-OVC/SHALLOW STRATO CU CLOUDS AND SOME
INTERMITTENT VERY LIGHT SNOW OR FLURRIES ACROSS THE WRN MTNS
TONIGHT...WHILE PARTLY CLOUDY SKIES ARE ANTICIPATED ELSEWHERE.
COLDEST TEMPS OF THE WINTER SEASON SO FAR IN MANY LOCATIONS WILL
OCCUR TONIGHT. MINS WILL BE IN THE 5-10F RANGE ACROSS THE NW HALF TO
TWO-THIRDS OF THE CWA...WITH LOWER TEENS THROUGHOUT THE SE ZONES.
THE NEXT WEAK...CLIPPER SYSTEM SLIDES SE FROM THE GLAKES REGION
WEDNESDAY LEADING TO INCREASING CLOUDS AND PERHAPS A PERIOD OF LIGHT
SNOW...OR MORE LIKELY SNOW SHOWERS /MAINLY ACROSS THE NW HALF OF
PENN/. LIGHT ACCUMS OF A COATING TO ONE INCH WILL BE POSSIBLE OVER
THE NW MTNS.
MAX TEMPS WED WILL BE 5 TO 8 DEG F WARMER ACROSS THE CENTRAL AND NW
ZONES AND AT LEAST A FEW DEG F HIGHER THROUGHOUT THE LOWER SUSQ
VALLEY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE SECOND HALF OF THIS WEEK FEATURES GRADUALLY RISING MID/UPPER
LEVEL HEIGHTS AND A TREND TOWARD ZONAL FLOW. ASIDE FROM SOME
/LIGHTER/ LES AND OROGRAPHIC SNOW SHOWERS ACROSS THE NW MTNS AND
LAURELS WEDNESDAY NIGHT THROUGH MIDDAY THURSDAY...DRY WEATHER WITH A
RETURN TO ABOVE NORMAL TEMPS WILL FOLLOW FOR FRIDAY AND SATURDAY AS
AN POTENT LOW PRESSURE AREA SCOOTS BY ACROSS SOUTHERN CANADA.
A COLD FRONT /EXTENDING SOUTH FROM THE SERN CANADA LOW/ MAY LINK UP
WITH AN INVERTED LLVL TROUGH EXTENDED NORTH FROM THE TENN VALLEY OR
SRN APPALACHIANS TO BRING INCREASING CLOUDS AND PERHAPS SOME LIGHT
SNOW LATER IN THE WEEKEND.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
LAKE EFFECT SNOW BANDS CONTINUE ACROSS THE NW HALF OF THE REGION
IN STRONG NW FLOW. STRONGEST BAND THROUGH MID MORNING WILL BE
LOCATED IN THE VICINITY OF KJST-KAOO...AND WITH INTENSITIES NEAR
40 DBZ IT WILL PRODUCE IFR CONDITIONS AS IT SLOWLY DRIFTS SOUTH
THROUGH MID MORNING. ELSEWHERE...LOCAL REDUCTIONS REMAIN POSSIBLE
IN LESS INTENSE SNOWBANDS IN THE NORTHERN TIER AND CENTRAL
MTNS...THOUGH PREVAILING CONDITIONS WILL BE MVFR/VFR.
CIGS SHOULD LIFT TO VFR IN MOST PLACES BY LATE MORNING AHEAD OF
ONE LAST SHORTWAVE SLIDING DOWN BACK SIDE OF TROUGH. THIS S/W
COULD BRING ADDITIONAL LIGHT SNOW TO NW MTNS AND LAURELS LATER
THIS AFTERNOON...BUT INTENSITY SHOULD REMAIN LIGHT WITH MVFR
RESTRICTIONS. OTHERWISE...THIS AFTERNOON AND OVERNIGHT WILL SEE
IMPROVING CONDITIONS AS SURFACE RIDGE BUILDS IN...KEEPING
CONDITIONS VFR THROUGH WED.
GUSTY NORTHWEST SURFACE WINDS TO 25 KTS WILL CONTINUE DURING THE
DAY TODAY...BEFORE GRADUALLY DIMINISHING THIS EVENING AND
ESPECIALLY OVERNIGHT.
OUTLOOK...
TUE...OCNL MVFR IN -SN NW. OTHERWISE PRIMARILY VFR WITH ISOLD
MVFR IN -SHSN.
WED...VFR.
WED NIGHT-SAT...PRIMARILY VFR. OCNL MVFR POSS IN NW MTNS/LAURELS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
PAZ004-005.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR PAZ006-010-
011-017.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ024-
033.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...LAMBERT/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
746 AM EST TUE JAN 3 2012
.SYNOPSIS...
THE COLDEST AIR SO FAR THIS WINTER SEASON WILL CONTINUE TO SWEEP
SOUTHEAST ACROSS THE GREAT LAKES AND INTO PENNSYLVANIA TODAY THROUGH
WEDNESDAY. FREQUENT LAKE EFFECT SNOW SHOWERS AND SOME HEAVY SQUALLS
WILL BE CONCENTRATED ACROSS THE NORTHWESTERN MOUNTAINS AND LAUREL
HIGHLANDS. SNOW SHOWERS OF LESSER INTENSITY AND BRIEF SQUALLS WILL
DRIFT INTO THE NORTHERN AND CENTRAL MOUNTAINS AT TIMES. A WARMUP TO
ABOVE NORMAL TEMPERATURES IS EXPECTED LATER THIS WEEK BEFORE ANOTHER
SURGE OF COLD AIR APPROACHES FOR LATE IN THE UPCOMING WEEKEND. THE
COLD AIR...WESTERLY FLOW AND WARM LAKES COULD PRODUCE MORE LAKE
EFFECT SNOW ACROSS WESTERN PENNSYLVANIA NEXT MONDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL NOON TODAY/...
LITTLE CHANGE IN AREAL COVERAGE AND INTENSITY OF SNOW SHOWERS...AND
NARROW BANDS OF SQUALLS ACROSS THE NRN AND WRN MTNS OF PENN THROUGH
MIDDAY TODAY.
WILL HAVE TO CLOSELY MONITOR THE PROGRESSION OF A COMPACT UPPER VORT
MAX...HEADED OUR WAY FROM FAR SRN ONTARIO THIS MORNING THROUGH THE
MIDDAY HOURS.
LATEST RUC AND 06Z NAM INDICATE AN INITIAL AREA OF STEEP 850-700 MB
LAPSE RATES /OF OVER 8C/KM/ SETTLING SOUTH OF THE MASON/DIXON LINE
EARLY TODAY...WITH THE AFOREMENTIONED UPPER VORT LOBE GENERATING A
SECOND AREA OF ENHANCED LOW TO MID LEVEL INSTABILITY DURING THE LATE
MORNING AND EARLY AFTERNOON ACROSS APPROX THE SW THIRD OF THE CWA.
NAM BUFKIT SHOWS A CROSS-HAIR SIGNATURE OF STRONG UVVEL WITHIN THE
FAVORABLE THERMAL RIBBON FOR DENDRITIC SNOW GROWTH. THIS EFFICIENT
SNOW MAKING MACHINE WILL BRING MOST AREAS OF CENTRAL OPEN ANOTHER
COATING TO ONE INCH OF SNOW...WITH SEVERAL INCHES OR MORE OF NEW
FLUFFY/WIND-WHIPPED SNOW FALLING ACROSS THE WRN MTNS AND SNOWBELT OF
WARREN COUNTY.
CONTINUED DEEP-LAYER COLD ADVECTION WILL KEEP TEMPS STEADY OR SLOWLY
FALLING...IN THE TEENS TO LOWER 20S ACROSS THE CENTRAL AND WESTERN
COUNTIES...AND MID TO UPPER 20S IN THE SUSQ VALLEY.
WIND CHILLS WILL FREQUENTLY DIP BELOW ZERO TODAY ACROSS THE NRN AND
WRN MTNS...AND HOLD IN THE SINGLE DIGITS TO LOWER TEENS ELSEWHERE.
&&
.SHORT TERM /NOON TODAY THROUGH 6 PM WEDNESDAY/...
WARMER AIR ALOFT MOVES IN TONIGHT DIMINISHING THE SNOW SHOWERS
RATHER QUICKLY. STEEP LLVL LAPSE RATES...WILL COMBINE WITH BACKING
BLYR WINDS AND WEAK ISENTROPIC UPGLIDE WITHIN THE 275-285K THETA
CHANNEL TO MAINTAIN BKN-OVC/SHALLOW STRATO CU CLOUDS AND SOME
INTERMITTENT VERY LIGHT SNOW OR FLURRIES ACROSS THE WRN MTNS
TONIGHT...WHILE PARTLY CLOUDY SKIES ARE ANTICIPATED ELSEWHERE.
COLDEST TEMPS OF THE WINTER SEASON SO FAR IN MANY LOCATIONS WILL
OCCUR TONIGHT. MINS WILL BE IN THE 5-10F RANGE ACROSS THE NW HALF TO
TWO-THIRDS OF THE CWA...WITH LOWER TEENS THROUGHOUT THE SE ZONES.
THE NEXT WEAK...CLIPPER SYSTEM SLIDES SE FROM THE GLAKES REGION
WEDNESDAY LEADING TO INCREASING CLOUDS AND PERHAPS A PERIOD OF LIGHT
SNOW...OR MORE LIKELY SNOW SHOWERS /MAINLY ACROSS THE NW HALF OF
PENN/. LIGHT ACCUMS OF A COATING TO ONE INCH WILL BE POSSIBLE OVER
THE NW MTNS.
MAX TEMPS WED WILL BE 5 TO 8 DEG F WARMER ACROSS THE CENTRAL AND NW
ZONES AND AT LEAST A FEW DEG F HIGHER THROUGHOUT THE LOWER SUSQ
VALLEY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE SECOND HALF OF THIS WEEK FEATURES GRADUALLY RISING MID/UPPER
LEVEL HEIGHTS AND A TREND TOWARD ZONAL FLOW. ASIDE FROM SOME
/LIGHTER/ LES AND OROGRAPHIC SNOW SHOWERS ACROSS THE NW MTNS AND
LAURELS WEDNESDAY NIGHT THROUGH MIDDAY THURSDAY...DRY WEATHER WITH A
RETURN TO ABOVE NORMAL TEMPS WILL FOLLOW FOR FRIDAY AND SATURDAY AS
AN POTENT LOW PRESSURE AREA SCOOTS BY ACROSS SOUTHERN CANADA.
A COLD FRONT /EXTENDING SOUTH FROM THE SERN CANADA LOW/ MAY LINK UP
WITH AN INVERTED LLVL TROUGH EXTENDED NORTH FROM THE TENN VALLEY OR
SRN APPALACHIANS TO BRING INCREASING CLOUDS AND PERHAPS SOME LIGHT
SNOW LATER IN THE WEEKEND.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
LAKE EFFECT SNOW BANDS CONTINUE ACROSS THE NW HALF OF THE REGION
IN STRONG NW FLOW. STRONGEST BAND THROUGH MID MORNING WILL BE
LOCATED IN THE VICINITY OF KJST-KAOO...AND WITH INTENSITIES NEAR
40 DBZ IT WILL PRODUCE IFR CONDITIONS AS IT SLOWLY DRIFTS SOUTH
THROUGH MID MORNING. ELSEWHERE...LOCAL REDUCTIONS REMAIN POSSIBLE
IN LESS INTENSE SNOWBANDS IN THE NORTHERN TIER AND CENTRAL
MTNS...THOUGH PREVAILING CONDITIONS WILL BE MVFR/VFR.
CIGS SHOULD LIFT TO VFR IN MOST PLACES BY LATE MORNING AHEAD OF
ONE LAST SHORTWAVE SLIDING DOWN BACK SIDE OF TROUGH. THIS S/W
COULD BRING ADDITIONAL LIGHT SNOW TO NW MTNS AND LAURELS LATER
THIS AFTERNOON...BUT INTENSITY SHOULD REMAIN LIGHT WITH MVFR
RESTRICTIONS. OTHERWISE...THIS AFTERNOON AND OVERNIGHT WILL SEE
IMPROVING CONDITIONS AS SURFACE RIDGE BUILDS IN...KEEPING
CONDITIONS VFR THROUGH WED.
GUSTY NORTHWEST SURFACE WINDS TO 25 KTS WILL CONTINUE DURING THE
DAY TODAY...BEFORE GRADUALLY DIMINISHING THIS EVENING AND
ESPECIALLY OVERNIGHT.
OUTLOOK...
TUE...OCNL MVFR IN -SN NW. OTHERWISE PRIMARILY VFR WITH ISOLD
MVFR IN -SHSN.
WED...VFR.
WED NIGHT-SAT...PRIMARILY VFR. OCNL MVFR POSS IN NW MTNS/LAURELS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
PAZ004-005.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR PAZ006-010-
011-017.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ024-
033.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...LAMBERT/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
455 AM EST TUE JAN 3 2012
.SYNOPSIS...
THE COLDEST AIR SO FAR THIS WINTER SEASON WILL CONTINUE TO SWEEP
SOUTHEAST ACROSS THE GREAT LAKES AND INTO PENNSYLVANIA TODAY THROUGH
WEDNESDAY. FREQUENT LAKE EFFECT SNOW SHOWERS AND SOME HEAVY SQUALLS
WILL BE CONCENTRATED ACROSS THE NORTHWESTERN MOUNTAINS AND LAUREL
HIGHLANDS. SNOW SHOWERS OF LESSER INTENSITY AND BRIEF SQUALLS WILL
DRIFT INTO THE NORTHERN AND CENTRAL MOUNTAINS AT TIMES. A WARMUP TO
ABOVE NORMAL TEMPERATURES IS EXPECTED LATER THIS WEEK BEFORE ANOTHER
SURGE OF COLD AIR APPROACHES FOR LATE IN THE UPCOMING WEEKEND. THE
COLD AIR...WESTERLY FLOW AND WARM LAKES COULD PRODUCE MORE LAKE
EFFECT SNOW ACROSS WESTERN PENNSYLVANIA NEXT MONDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL NOON TODAY/...
LITTLE CHANGE IN AREAL COVERAGE AND INTENSITY OF SNOW SHOWERS...AND
NARROW BANDS OF SQUALLS ACROSS THE NRN AND WRN MTNS OF PENN THROUGH
MIDDAY TODAY.
WILL HAVE TO CLOSELY MONITOR THE PROGRESSION OF A COMPACT UPPER VORT
MAX...HEADED OUR WAY FROM FAR SRN ONTARIO THIS MORNING THROUGH THE
MIDDAY HOURS.
LATEST RUC AND 06Z NAM INDICATE AN INITIAL AREA OF STEEP 850-700 MB
LAPSE RATES /OF OVER 8C/KM/ SETTLING SOUTH OF THE MASON/DIXON LINE
EARLY TODAY...WITH THE AFOREMENTIONED UPPER VORT LOBE GENERATING A
SECOND AREA OF ENHANCED LOW TO MID LEVEL INSTABILITY DURING THE LATE
MORNING AND EARLY AFTERNOON ACROSS APPROX THE SW THIRD OF THE CWA.
NAM BUFKIT SHOWS A CROSS-HAIR SIGNATURE OF STRONG UVVEL WITHIN THE
FAVORABLE THERMAL RIBBON FOR DENDRITIC SNOW GROWTH. THIS EFFICIENT
SNOW MAKING MACHINE WILL BRING MOST AREAS OF CENTRAL OPEN ANOTHER
COATING TO ONE INCH OF SNOW...WITH SEVERAL INCHES OR MORE OF NEW
FLUFFY/WIND-WHIPPED SNOW FALLING ACROSS THE WRN MTNS AND SNOWBELT OF
WARREN COUNTY.
CONTINUED DEEP-LAYER COLD ADVECTION WILL KEEP TEMPS STEADY OR SLOWLY
FALLING...IN THE TEENS TO LOWER 20S ACROSS THE CENTRAL AND WESTERN
COUNTIES...AND MID TO UPPER 20S IN THE SUSQ VALLEY.
WIND CHILLS WILL FREQUENTLY DIP BELOW ZERO TODAY ACROSS THE NRN AND
WRN MTNS...AND HOLD IN THE SINGLE DIGITS TO LOWER TEENS ELSEWHERE.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
WARMER AIR ALOFT MOVES IN TONIGHT DIMINISHING THE SNOW SHOWERS
RATHER QUICKLY. STEEP LLVL LAPSE RATES...WILL COMBINE WITH BACKING
BLYR WINDS AND WEAK ISENTROPIC UPGLIDE WITHIN THE 275-285K THETA
CHANNEL TO MAINTAIN BKN-OVC/SHALLOW STRATO CU CLOUDS AND SOME
INTERMITTENT VERY LIGHT SNOW OR FLURRIES ACROSS THE WRN MTNS
TONIGHT...WHILE PARTLY CLOUDY SKIES ARE ANTICIPATED ELSEWHERE.
COLDEST TEMPS OF THE WINTER SEASON SO FAR IN MANY LOCATIONS WILL
OCCUR TONIGHT. MINS WILL BE IN THE 5-10F RANGE ACROSS THE NW HALF TO
TWO-THIRDS OF THE CWA...WITH LOWER TEENS THROUGHOUT THE SE ZONES.
THE NEXT WEAK...CLIPPER SYSTEM SLIDES SE FROM THE GLAKES REGION
WEDNESDAY LEADING TO INCREASING CLOUDS AND PERHAPS A PERIOD OF LIGHT
SNOW...OR MORE LIKELY SNOW SHOWERS /MAINLY ACROSS THE NW HALF OF
PENN/. LIGHT ACCUMS OF A COATING TO ONE INCH WILL BE POSSIBLE OVER
THE NW MTNS.
MAX TEMPS WED WILL BE 5 TO 8 DEG F WARMER ACROSS THE CENTRAL AND NW
ZONES AND AT LEAST A FEW DEG F HIGHER THROUGHOUT THE LOWER SUSQ
VALLEY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE SECOND HALF OF THIS WEEK FEATURES GRADUALLY RISING MID/UPPER
LEVEL HEIGHTS AND A TREND TOWARD ZONAL FLOW. ASIDE FROM SOME
/LIGHTER/ LES AND OROGRAPHIC SNOW SHOWERS ACROSS THE NW MTNS AND
LAURELS WEDNESDAY NIGHT THROUGH MIDDAY THURSDAY...DRY WEATHER WITH A
RETURN TO ABOVE NORMAL TEMPS WILL FOLLOW FOR FRIDAY AND SATURDAY AS
AN POTENT LOW PRESSURE AREA SCOOTS BY ACROSS SOUTHERN CANADA.
A COLD FRONT /EXTENDING SOUTH FROM THE SERN CANADA LOW/ MAY LINK UP
WITH AN INVERTED LLVL TROUGH EXTENDED NORTH FROM THE TENN VALLEY OR
SRN APPALACHIANS TO BRING INCREASING CLOUDS AND PERHAPS SOME LIGHT
SNOW LATER IN THE WEEKEND.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
GUSTY WINDS WILL CONTINUE ALONG THE ELEVATED REGIONS IN THE NW
MTNS AND THE LAUREL HIGHLANDS...WHILE WINDS CONTINUE TO GRADUALLY
DIMINISH FOR THE REST OF THE REGION.
BIGGER STORY REMAINS NUMEROUS LAKE EFFECT SNOW SHOWERS THAT WILL
CONTINUE ACROSS THE NW MTNS /KBFD/ AND UPSLOPE SNOWS IN THE LAUREL
HIGHLANDS /KJST/ AND AT TIMES AOO...UNV AND IPT THROUGH THE
AFTERNOON. STRONG MULTI LAKE CONNECTION WILL ALLOWED THESE LAKE
ENHANCED BANDS TO OCCASIONALLY PROPAGATE INTO CENTRAL MTNS AS
WELL. PERIODS OF MVFR-IFR CIGS WILL OCCUR IN HIGHER ELEVATIONS OF
THE WEST...AND OCCASIONALLY INTO THE CENTRAL MTNS. JST AND BFD
WILL REACH LIFR AT TIMES WITH MAINLY MVFR TO IFR IN THE SNOW
BANDS. VFR CONDITIONS WILL PREVAIL OUTSIDE OF AND IN BETWEEN THE
HEAVIER SNOW BANDS. HAVE USED MAINLY TEMPO GROUPS TO INDICATE
SUCH. THE SUSQ VALLEY WILL REMAIN VFR THROUGH THE TAF PERIOD.
OUTLOOK...
TUE...OCNL MVFR IN -SN NW. OTHERWISE PRIMARILY VFR WITH ISOLD
MVFR IN -SHSN.
WED-SAT...PRIMARILY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
PAZ004-005.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR PAZ006-010-
011-017.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ024-
033.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT
AVIATION...CERU/RXR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
537 AM CST TUE JAN 3 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
310 AM CST TUE JAN 3 2012
MAIN FORECAST CONCERNS THIS PACKAGE...CLOUDS AND TEMPERATURES
THROUGH THE PERIOD.
06Z DATA ANALYSIS HAD A RIDGE OF HIGH PRESSURE LOCATED FROM THE MN
ARROWHEAD TO EASTERN IA AND EASTERN TX. CLEAR SKIES OVER WI/
EASTERN IA/NORTHERN IL EAST OF THE RIDGE AXIS WITH LOW CLOUDS/-SN
EARLY THIS MORNING LIMITED TO THE LEE SIDES OF LK SUPERIOR/MI.
PRESSURE FALLS ACROSS THE NORTHERN PLAINS AHEAD OF THE NEXT CO TO
MT LEE TROUGH AND LOW IN SOUTHERN SASKAT. SOUTH WINDS ALREADY
DEVELOPING OVER WESTERN MN/IA. SOME MID/HIGH CLOUDS SPREADING ACROSS
MN/IA...SPILLING THRU THE MID/UPPER LEVEL RIDGE AXIS...KEEPING
TEMPS ACROSS THE SNOW COVERED PORTIONS OF CENTRAL/SOUTHERN MN FROM
DIVING BELOW ZERO.
NO GLARING ERRORS NOTED WITH 03.00Z MODEL INITIALIZATIONS AND
SOLUTIONS VERY SIMILAR FOR TODAY THRU THU NIGHT. WEAKEST POINT OF
INITIALIZATION AS USUAL THE SFC-925MB DEW POINT/RH FIELDS...BUT
THESE DIFFERENCES LOOK TO HAVE LITTLE IF ANY IMPACT ON THE SHORT-
TERM FCST THIS CYCLE. DPROG/DT OF 500MB HGTS AT 03.00Z SHOWED MODEL
RUNS OF 01.00Z AND 02.00Z VERIFIED REASONABLY WELL ACROSS NOAM/
EASTER PAC WITH BETTER RUN-TO-RUN CONSISTENCY ON SHORTWAVE FEATURES
TO ECMWF. MODELS CONVERGING ON A TIGHTER CONSENSUS/COMPROMISE
SOLUTION AS THE NORTHERN ROCKIES SHORTWAVE DROPS QUICKLY EAST AND
SOUTHEAST TODAY/TONIGHT. TIGHTER CONSENSUS DEVELOPING FOR WED THRU
THU NIGHT AS HGTS RISE/RIDGING ALOFT BUILDS EAST ACROSS THE UPPER
MIDWEST WED/THU THEN THE NEXT TROUGH MOVES INTO THE NORTHERN PLAINS
THU NIGHT. GFS/ECMWF WITH SOMEWHAT BETTER RUN-TO-RUN CONSISTENCY
THAN THE OTHERS TONIGHT THRU THU NIGHT. CHECK OF OBS VS. MODEL DATA
AT 06Z SHOWED MODELS WITH A DECENT HANDLE ON THE SFC RIDGE OVER THE
REGION AND THE LEE TROUGHING/SASKAT LOW. PER WV IMAGERY ALL LOOKED
GOOD WITH THE SHORTWAVE QUICKLY TRAVERSING THE NORTHERN ROCKIES AND
SHORTWAVE DETAILS ELSEWHERE ACROSS NOAM/EASTERN PAC. NO CLEAR MODEL
FAVORITE AND WITH THE TREND TOWARD THE TIGHTER COMPROMISE
CONSENSUS...FAVORED THE CONSENSUS. SHORT TERM FCST CONFIDENCE
REMAINS GOOD THIS CYCLE.
FOR THE SHORT TERM...FCST CONCERNS RATHER MINOR THRU THE SHORT
TERM THIS CYCLE. SFC RIDGE AXIS MOVES QUICKLY EAST OF THE AREA TODAY
AS THE NORTHERN ROCKIES SHORTWAVE MOVES TO NORTHWEST MN/EASTERN SD
BY 00Z AND THE LEE TROUGH/FRONT MOVE EAST TO ABOUT THE SAME
POSITION. GRADIENT TIGHTENS OVER THE AREA BY MID-DAY...WITH BRISK
SOUTH WINDS 15-25KT EXPECTED IN THE OPEN AREAS/RIDGE TOPS.
MDT/STRONG LOW LEVEL WARM ADVECTION RESULTS IN ABOUT 6C OF 925MB
WARMING TODAY. WITH FLATTENING MID/UPPER LEVEL FLOW OVER THE AREA
TODAY...AND AHEAD OF THE APPROACHING SHORTWAVE...CONSIDERABLE HIGH
LEVEL MOISTURE/CLOUDS EXPECTED TO SPREAD ACROSS THE AREA. CLOUDS
WILL TEMPER WARM-UP TODAY WITH SOUTHERLY FLOW OVER MOSTLY SNOW-
FREE GROUND. IF MORE SUNSHINE OCCURS THAN EXPECTED THIS AFTERNOON...
HIGH TEMPS COULD EASILY POP INTO THE LOW/MID 30S OVER THE SOUTH HALF
OF THE FCST AREA. SFC-MID LEVEL TROUGH MOVE QUICKLY ACROSS THE AREA
THIS EVENING. MODEL SOUNDINGS/X-SECTIONS CONTINUE TO INDICATE COLUMN
REMAINS QUITE DRY IN THE 850-650MB LAYER AS THIS TROUGH PASSES.
HAVE DOUBTS ABOUT FLURRIES IN GRIDS THIS EVENING OVER THE NORTHEAST
END OF THE FCST AREA BUT WILL LEAVE THEM TO BLEND WITH NEIGHBORING
GRIDS. GRADIENT WINDS AHEAD OF/BEHIND THE FRONT/TROUGH WILL KEEP THE
BOUNDARY LAYER STIRRED TONIGHT AND LOWS ABOVE NORMAL. SHORT-LIVED
NORTHERLY FLOW/LOW LEVEL COLD ADVECTION MOVES ACROSS THE AREA LATE
TONIGHT. NEXT LEE TROUGH AND LOW MOVING INTO CENTRAL CAN ALREADY
TURNS THE LOW LEVEL WINDS WESTERLY WED AND SPREAD WARM ADVECTION
ACROSS MN/IA/WI. TEMPS TO CONTINUE MODERATING WED. AS THE CAN LOW
MOVES TO NEAR LK WINNIPEG THU ANOTHER ROUND OF MDT/STRONG LOW LEVEL
WARM ADVECTION SPREADS ACROSS THE REGION. SFC PRESSURE GRADIENT NOT
THAT STRONG ACROSS THE AREA THU WITH WINDS MOSTLY 5-10KTS. FLAT
RIDGING OVER THE NORTHERN PLAINS/UPPER MIDWEST BY LATER THU...WITH
MODELS INDICATING SOME MID/HIGH LEVEL MOISTURE AHEAD OF THE NEXT
TROUGH INTO THE NORTHERN ROCKIES WILL SPILL THRU THE RIDGING AND
ACROSS THE AREA. THE LIGHT-ISH WINDS AND SOME HIGH CLOUDS THU WILL
LIMIT MIXING AND TEMPER THE WARM-UP. HIGHS THU STILL EXPECTED TO BE
IN THE MID 30S-MID 40S...SOME 10-20F ABOVE NORMAL. CAN LOW TRACKS TO
NORTH OF LK SUPERIOR THU NIGHT...DRAGGING A COLD FRONT ACROSS THE
AREA. A MODIFIED PACIFIC AIRMASS BEHIND THE FRONT WITH LIMITED COLD
ADVECTION/COOL-DOWN BEHIND THE FRONT. LOWS THU NIGHT TO REMAIN WELL
ABOVE NORMAL WITH LIGHT/MDT GRADIENT WINDS FOR BOUNDARY LAYER
MIXING.
NUMERICAL TEMP GUIDANCE FOR HIGHS/LOWS TODAY THRU THU NIGHT
GENERALLY SIMILAR. FAVORED A BLEND OF THE GUIDANCE VALUES FOR LOWS
TONIGHT THRU THU NIGHT. HIGHS STILL LOOK BIASED TOWARD JAN
CLIMATOLOGY AND THE EXPECTATION OF A FEW INCHES OF SNOW COVER ACROSS
THE LANDSCAPE. ONLY PLACE IN THE FCST AREA THIS EXISTS IS ALONG/
NORTH OF HWY 29 ACROSS NORTH-CENTRAL WI. ELSEWHERE MOSTLY AN INCH OR
LESS OF SNOW COVER. TRENDED TOWARD WARMER OF GUIDANCE HIGHS ACROSS
THE CENTRAL/SOUTH PARTS OF THE FCST AREA TODAY THRU THU AND RAISED
THESE A CATEGORY ACROSS THE SOUTHERN THIRD.
.LONG TERM...FRIDAY THROUGH MONDAY
310 AM CST TUE JAN 3 2012
MEDIUM RANGE MODEL RUNS OF 03.00Z IN RATHER GOOD AGREEMENT FOR FRI
THRU MON...AS BROAD LONGWAVE DEVELOPS OVER THE GREAT LAKES
FRI/SAT...THEN PROGRESSES INTO THE EASTERN CONUS SUN/MON. EVEN A
GOOD CONSENSUS ON A SHORTWAVE TROUGH TO DROP INTO THE REGION SUN...
BETTER THAN HAS BEEN SEEN AT THE DAY 6 TIME RANGE MUCH OF THE
AUTUMN/EARLY WINTER. LONG-TERM FCST CONFIDENCE ABOVE AVERAGE THIS
CYCLE. THE LOW LEVEL COLD ADVECTION FROM THU NIGHT CONTINUES ACROSS
THE AREA FRI...BUT WITH FLOW MORE WESTERLY THAN NORTHERLY AND THE
MODIFIED PACIFIC AIRMASS...APPEARS FRI TO BE AS WARM OR WARMER THAN
THU. SHORTWAVE TROUGH DROPS ACROSS THE WESTERN GREAT LAKES SAT. WITH
A COOLER COLUMN UNDER THIS TROUGH...MODELS INDICATING SOME DEEPER
SATURATION MAY OCCUR...ESPECIALLY OVER THE NORTHEAST HALF OF THE
FCST AREA. MAY YET NEED A SMALL -SN CHANCE ALONG/EAST OF THE MS
RIVER SAT AFTERNOON/EVENING BUT FOLLOWED THE MODEL CONSENSUS AND
LEFT SAT DRY FOR NOW. ANOTHER SHORTWAVE TROUGH LOOKS TO DROP ACROSS
THE REGION SUN. AIRMASS WITH THIS ONE DRIER ABOVE 850MB...WITH THIS
WAVE LOOKING TO DO LITTLE MORE THAN BRING A RE-ENFORCING SHOT OF
COOLER AIR TO THE REGION. BY MONDAY MODELS TREND PROGRESSIVE WITH
THE TROUGH AND STRONG HGT RISES/LOW LEVEL WARM ADVECTION...FROM THE
NORTHERN PLAINS...TO SPREAD BACK INTO THE UPPER MIDWEST...
CONTINUING THE GENERALLY MILD AND LIMITED SNOWFALL PATTERN WELL
INTO JAN.
FURTHER OUT IN TIME...MEDIUM RANGE MODELS HINTING AT A STRONGER
SYSTEM TO MOVE ACROSS THE UPPER MIDWEST FOR THE MIDDLE OF NEXT
WEEK...WITH POTENTIAL FOR SOME SNOW FALL. DETAILS ON THIS SKETCHY AT
BEST AND ANY CONFIDENCE QUITE LOW AT THIS TIME RANGE.
&&
.AVIATION...TODAY AND TONIGHT
537 AM CST TUE JAN 3 2012
MAIN FOCUS AT THE TAF SITES IS WITH THE WIND IN REGARD TO HOW HIGH
IT WILL GUST OUT OF THE SOUTH TODAY AND THEN WHEN A COLD FRONT
WILL COME THROUGH TONIGHT AND BRING WINDS OUT OF THE NORTHWEST. A
RIDGE AXIS OF HIGH PRESSURE HAS PUSHED EAST OF THE MISSISSIPPI
RIVER WITH WINDS COMING AROUND TO THE SOUTH AT RST/LSE. WINDS WILL
START OUT LIGHT BEFORE PICKING UP THOUGH THE MORNING HOURS.
03.10Z RUC FORECAST SOUNDINGS ARE SHOWING A MIXED LAYER UP TO
AROUND 950MB TODAY WITH MOMENTUM TRANSFER SHOWING ABOUT 24-28KT
GUSTS TO BE ABLE TO BE MIXED DOWN AT RST THIS AFTERNOON. WINDS
WILL BE LIGHTER AT LSE WITH GUSTS TOPPING OUT AROUND 20KT. A COLD
FRONT WILL THEN MOVE INTO THE REGION THIS EVENING AND GO THROUGH
RST AROUND 6Z AND LSE AROUND 8Z. NO PRECIPITATION IS EXPECTED WITH
THIS FRONTAL PASSAGE...BUT SOME MID TO HIGH LEVEL CLOUDS WILL
ENTER THE REGION WITH IT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
310 AM CST TUE JAN 3 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1055 AM MST TUE JAN 3 2012
.UPDATE...
950 AM MST TUE JAN 3 2012
MADE MINOR ADJUSTMENTS TO THE CURRENT FORECAST...WITH MAIN CHANGE
BEING TO INCREASE CLOUD COVER DURING THE DAY AND EVENING. HAVE
SOME CONCERN FOR FIRE WEATHER HIGHLITES DURING THE AFTERNOON...BUT
WILL HOLD OFF ISSUING ANYTHING FOR RIGHT NOW DUE UNCERTAINTY OF
WINDS REMAINING STRONG LONG ENOUGH TO MEET CRITERIA.
LATEST SATELLITE AND RUC ANALYSIS SHOW HIGH CLOUDS MOVING OVER THE
HIGH PLAINS AHEAD OF A SHORT WAVE TROUGH. EXPECT CLOUD COVER TO
INCREASE THROUGH THE DAY THEN DISSIPATE DURING THE EVENING BEHIND
THE TROUGH AS IT EXITS THE AREA. AT THE SURFACE WINDS HAVE TURNED TO
THE NORTHWEST AND HAD SOME GUSTS UP TO 30 MPH DURING THE MORNING
BEFORE CLOUD COVER MOVED IN...MOST LIKELY DUE TO THE STRONG WINDS
OFF THE SURFACE MIXING DOWN AS TEMPERATURES WARMED.
AFTER CLOUDS MOVED OVER WINDS HAVE TURNED TO MORE OF A WESTERLY
DIRECTION AND LIGHTENED. POINT SOUNDINGS SHOW THE STRONGER WINDS
WILL MIX DOWN TO THE SURFACE...HOWEVER WITH THE ADDED CLOUD COVER
AM NOT AS CONFIDENT THAT WINDS WILL GUST UP 30 MPH LONG ENOUGH TO
MEET FIRE WEATHER CRITERIA. HOWEVER TEMPERATURES SEEM TO BE
WARMING DESPITE THE CLOUD COVER SO SOME MIXING WILL CERTAINLY BE
POSSIBLE. WILL CONTINUE TO MONITOR OBSERVATIONS.
JTL
&&
.DISCUSSION...
300 AM MST TUE JAN 3 2012
TODAY-THURSDAY NIGHT...DRY AND WARM THROUGH THE PERIOD. A COLD
FRONT WILL MOVE THROUGH LATE THIS MORNING/EARLY AFTERNOON WITH
GUSTY NORTHWEST WINDS. BEFORE IT DOES SHOULD SEE AFTERNOON
TEMPERATURES WARM INTO THE LOW TO MID 60S. FOR THE GREELEY AND
WICHITA COUNTY AREAS SFC FLOW IS FROM THE NORTHWEST AND NOT THE
SNOW PACK AS IN PREVIOUS DAYS. THIS SHOULD ALLOW TEMPERATURES TO
WARM TO AT LEAST THE MID 50S PER 850 TEMPERATURES. COULD BE
SEVERAL DEGREES HIGHER GIVEN FLOW FROM NORTHWEST. SLIGHTLY COOLER
TEMPERATURES ON WEDNESDAY WITH 55 TO 60 ACROSS THE AREA UNDER A
MOSTLY SUNNY SKY. ON THURSDAY SFC FLOW FROM THE SOUTHWEST AHEAD OF
A COLD FRONT THAT MOVES THROUGH THURSDAY NIGHT. HIGH TEMPERATURES
GENERALLY 65 TO 70 EXCEPT OVER GREELEY AND WICHITA COUNTIES WHERE
AROUND 60/LOW 60S EXPECTED AS SOME LINGERING SNOW COVER EXPECTED
SOUTH/SOUTHWEST OF THE AREA AND FLOW OFF IT MOVES INTO THOSE
AREAS.
BASED ON CURRENT FORECAST RECORD OR NEAR RECORD HIGH EXPECTED
TODAY AT GOODLAND (68 IN 2006). ON THURSDAY RECORD OR NEAR RECORD
HIGHS POSSIBLE AT GOODLAND (71 IN 1927) AND YUMA (66 IN 1965).
007
IN THE EXTENDED (FRIDAY-MONDAY)...MEDIUM RANGE MODELS IN
REASONABLE AGREEMENT EARLY IN THE PERIOD WITH H5 RIDGE BREAKING
DOWN AND BROAD TROUGHING SPREADING OVER THE AREA. DIFFERENCES
REMAIN WITH RESPECT TO STRENGTH OF SHORT WAVE TROUGH EXPECTED TO
SLIDE OVER AREA ON SATURDAY AND SUNDAY. LATEST MODELS AND
ESPECIALLY GEFS PRECIP PROBABILITIES SUGGEST SMALL PRECIP THREAT
ON BOTH FRIDAY NIGHT AND SATURDAY...WITH GEFS SUGGESTING FRIDAY
NIGHT MIGHT ACTUALLY HAVE THE BEST CHANCES. WHILE THERE IS
EXPECTED TO BE LARGE SCALE ASCENT AND SOME POTENTIAL
INSTABILITY...GEFS DATA IS RADICALLY DIFFERENT FROM BOTH 12 AND 24
HOURS AGO SO DO NOT THINK GOING MUCH ABOVE MINIMAL POPS IN THE
WEST IS WARRANTED FOR FRIDAY NIGHT GIVEN OPERATIONAL DATA AND
EXPECTED CONVECTIVE/SPOTTY NATURE OF ANY PRECIPITATION.
OTHERWISE...TEMPS FALLING BACK TO NEAR/BELOW NORMAL STILL LOOK ON
TRACK FOR PERIOD...WITH TEMPS BEGINNING TO WARM BACK UP AS H5
RIDGE REDEVELOPS OVER THE AREA ON MONDAY.
&&
.AVIATION...
1046 AM MST TUE JAN 3 2012
VFR CONDITIONS CAN BE EXPECTED FOR THE 18Z TAFS. BIGGEST QUESTION
WITH THE TAFS WILL BE THE STRENGTH OF THE WINDS. CURRENTLY MODELS
ARE NOT HANDLING THE CLOUD COVER WELL...HAVING PARTLY CLOUDY SKIES
AT BEST. CURRENTLY THINKING THE CLOUDS WILL REMAIN THROUGH THE
AFTERNOON AND DECREASE DURING THE EVENING AS THE SHORT WAVE TROUGH
MOVES THROUGH.
WITH THE ADDED CLOUD COVER...THE STRONGER WINDS ABOVE THE SURFACE
WILL NOT BE ABLE TO FULLY MIX DOWN. HOWEVER WITH THE UNSEASONABLY
WARM TEMPERATURES...AM THINKING GUSTS AROUND 20 KTS WILL BE
POSSIBLE DURING THE AFTERNOON DESPITE THE CLOUD COVER.
JTL
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1022 AM MST TUE JAN 3 2012
.UPDATE...
950 AM MST TUE JAN 3 2012
MADE MINOR ADJUSTMENTS TO THE CURRENT FORECAST...WITH MAIN CHANGE
BEING TO INCREASE CLOUD COVER DURING THE DAY AND EVENING. HAVE
SOME CONCERN FOR FIRE WEATHER HIGHLITES DURING THE AFTERNOON...BUT
WILL HOLD OFF ISSUING ANYTHING FOR RIGHT NOW DUE UNCERTAINTY OF
WINDS REMAINING STRONG LONG ENOUGH TO MEET CRITERIA.
LATEST SATELLITE AND RUC ANALYSIS SHOW HIGH CLOUDS MOVING OVER THE
HIGH PLAINS AHEAD OF A SHORT WAVE TROUGH. EXPECT CLOUD COVER TO
INCREASE THROUGH THE DAY THEN DISSIPATE DURING THE EVENING BEHIND
THE TROUGH AS IT EXITS THE AREA. AT THE SURFACE WINDS HAVE TURNED TO
THE NORTHWEST AND HAD SOME GUSTS UP TO 30 MPH DURING THE MORNING
BEFORE CLOUD COVER MOVED IN...MOST LIKELY DUE TO THE STRONG WINDS
OFF THE SURFACE MIXING DOWN AS TEMPERATURES WARMED.
AFTER CLOUDS MOVED OVER WINDS HAVE TURNED TO MORE OF A WESTERLY
DIRECTION AND LIGHTENED. POINT SOUNDINGS SHOW THE STRONGER WINDS
WILL MIX DOWN TO THE SURFACE...HOWEVER WITH THE ADDED CLOUD COVER
AM NOT AS CONFIDENT THAT WINDS WILL GUST UP 30 MPH LONG ENOUGH TO
MEET FIRE WEATHER CRITERIA. HOWEVER TEMPERATURES SEEM TO BE
WARMING DESPITE THE CLOUD COVER SO SOME MIXING WILL CERTAINLY BE
POSSIBLE. WILL CONTINUE TO MONITOR OBSERVATIONS.
JTL
&&
.DISCUSSION...
300 AM MST TUE JAN 3 2012
TODAY-THURSDAY NIGHT...DRY AND WARM THROUGH THE PERIOD. A COLD
FRONT WILL MOVE THROUGH LATE THIS MORNING/EARLY AFTERNOON WITH
GUSTY NORTHWEST WINDS. BEFORE IT DOES SHOULD SEE AFTERNOON
TEMPERATURES WARM INTO THE LOW TO MID 60S. FOR THE GREELEY AND
WICHITA COUNTY AREAS SFC FLOW IS FROM THE NORTHWEST AND NOT THE
SNOW PACK AS IN PREVIOUS DAYS. THIS SHOULD ALLOW TEMPERATURES TO
WARM TO AT LEAST THE MID 50S PER 850 TEMPERATURES. COULD BE
SEVERAL DEGREES HIGHER GIVEN FLOW FROM NORTHWEST. SLIGHTLY COOLER
TEMPERATURES ON WEDNESDAY WITH 55 TO 60 ACROSS THE AREA UNDER A
MOSTLY SUNNY SKY. ON THURSDAY SFC FLOW FROM THE SOUTHWEST AHEAD OF
A COLD FRONT THAT MOVES THROUGH THURSDAY NIGHT. HIGH TEMPERATURES
GENERALLY 65 TO 70 EXCEPT OVER GREELEY AND WICHITA COUNTIES WHERE
AROUND 60/LOW 60S EXPECTED AS SOME LINGERING SNOW COVER EXPECTED
SOUTH/SOUTHWEST OF THE AREA AND FLOW OFF IT MOVES INTO THOSE
AREAS.
BASED ON CURRENT FORECAST RECORD OR NEAR RECORD HIGH EXPECTED
TODAY AT GOODLAND (68 IN 2006). ON THURSDAY RECORD OR NEAR RECORD
HIGHS POSSIBLE AT GOODLAND (71 IN 1927) AND YUMA (66 IN 1965).
007
IN THE EXTENDED (FRIDAY-MONDAY)...MEDIUM RANGE MODELS IN
REASONABLE AGREEMENT EARLY IN THE PERIOD WITH H5 RIDGE BREAKING
DOWN AND BROAD TROUGHING SPREADING OVER THE AREA. DIFFERENCES
REMAIN WITH RESPECT TO STRENGTH OF SHORT WAVE TROUGH EXPECTED TO
SLIDE OVER AREA ON SATURDAY AND SUNDAY. LATEST MODELS AND
ESPECIALLY GEFS PRECIP PROBABILITIES SUGGEST SMALL PRECIP THREAT
ON BOTH FRIDAY NIGHT AND SATURDAY...WITH GEFS SUGGESTING FRIDAY
NIGHT MIGHT ACTUALLY HAVE THE BEST CHANCES. WHILE THERE IS
EXPECTED TO BE LARGE SCALE ASCENT AND SOME POTENTIAL
INSTABILITY...GEFS DATA IS RADICALLY DIFFERENT FROM BOTH 12 AND 24
HOURS AGO SO DO NOT THINK GOING MUCH ABOVE MINIMAL POPS IN THE
WEST IS WARRANTED FOR FRIDAY NIGHT GIVEN OPERATIONAL DATA AND
EXPECTED CONVECTIVE/SPOTTY NATURE OF ANY PRECIPITATION.
OTHERWISE...TEMPS FALLING BACK TO NEAR/BELOW NORMAL STILL LOOK ON
TRACK FOR PERIOD...WITH TEMPS BEGINNING TO WARM BACK UP AS H5
RIDGE REDEVELOPS OVER THE AREA ON MONDAY.
&&
.AVIATION...
439 AM MST TUE JAN 3 2012
FOR 12Z TAFS...VFR CONDITIONS EXPECTED FOR ENTIRE PERIOD. WHILE
LIGHT WINDS...CLEAR SKIES AND LOW DEWPOINT DEPRESSIONS ARE BEING
OBSERVED AND ARE EXPECTED TO CONTINUE THROUGH THE MORNING
HOURS...VERTICAL MOISTURE PROFILES VERY SHALLOW AND THINK FOG
THREAT IS MINIMAL. WINDS WILL SHIFT TO THE NORTH AND INCREASE
DURING THE AFTERNOON HOURS...WITH A POTENTIAL FOR A BRIEF PERIOD
OF STRONG WINDS AROUND 21Z. COULD SEE A GUST OR TWO IN EXCESS OF
30 KTS DURING THIS TIME BEFORE WINDS DECOUPLE AFTER SUNSET.
JRM
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
325 PM EST TUE JAN 3 2012
.SYNOPSIS...
NORTHWEST WINDS ACROSS THE GREAT LAKES WILL CONTINUE TO BRING SNOW
SHOWERS THROUGH THIS EVENING AND QUITE COLD TEMPERATURES THROUGH
TONIGHT.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
EXPECT LAKE EFFECT SNOW BANDS TO PERSIST ACROSS PARTS OF WESTERN
PENNSYLVANIA THROUGH EARLY EVENING AS NORTHWEST FLOW OFF THE GREAT
LAKES CONTINUES.
PLAN TO EXTEND HEADLINES FOR WARNINGS AND ADVISORIES MAINLY ACROSS
WESTERN PA AND OVER THE WV/MD MOUNTAINS THROUGH EARLY EVENING WITH
ADDITIONAL ACCUMULATIONS OF 1 TO 3 INCHES IN PERSISTENT SNOW
BANDS.
NAM MODEL PROFILES SHOW CAPPING INVERSION LOWERING TO 5 KFT AGL BY
LATE EVENING. THIS SHOULD REDUCE COVERAGE AND INTENSITY OF REMAINING
SNOW SHOWERS.
AREAS OF BLOWING SNOW CAN ALSO BE EXPECTED THROUGH EARLY EVENING AS
WINDS GUST TO AROUND 30 MPH AT TIMES. WIND SPEEDS SHOULD GRADUALLY
SUBSIDE AFTER 02Z. WIND CHILLS OVERNIGHT WILL REMAIN IN THE SINGLE
DIGITS MOST AREAS AND SHOULD RANGE FROM ZERO TO MINUS 9 IN HIGHER
ELEVATIONS...JUST ABOVE THE WIND CHILL ADVISORY THRESHOLD.
A SHORTWAVE TROUGH WILL SWING SOUTHEAST ACROSS THE UPPER OHIO VALLEY
WEDNESDAY. THIS FAST MOVING SYSTEM WILL BRING SCATTERED SNOW SHOWERS
TO THE NORTHERN HALF OF THE FORECAST AREA AS GREATEST DYNAMICS AND
MOISTURE REMAIN NORTH AND EAST OF REGION.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
SCATTERED PRECIPITATION SHOULD TAPER OFF AS UPPER TROUGH EXITS
WEDNESDAY NIGHT. THURSDAY THROUGH FRIDAY SHOULD BE MAINLY DRY AS THE
UPPER FLOW FLATTENS AND A LOW PRESSURE SYSTEM TRACKS ACROSS TO OUR
NORTH THROUGH SOUTHERN CANADA.
TEMPERATURES WILL RECOVER WELL INTO THE 30S THURSDAY AFTERNOON AND
INTO THE 40S ON FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
PER RECENT HPC GUIDANCE, THAT SHOWED PREFERENCE TOWARD RECENT ECMWF
MODEL OUTPUT, EXPECT UPPER LEVEL JETSTREAM ACROSS THE U.S. TO BE
FAIRLY ZONAL THIS WEEKEND, THEN BACK MORE INTO THE NORTHWEST AS AN
UPPER RIDGE BUILDS ACROSS THE PLAINS. THE NET RESULT WILL BE
TEMPERATURES AVERAGING SLIGHTLY WARMER THAN NORMAL.
REGARDING DAILY DETAILS, STILL UNCERTAINTY REGARDING HOW CLOSE A LOW
PRESSURE SYSTEM, MOVING NORTHEASTWARD THROUGH THE EASTERN SEABOARD
THIS WEEKEND, WILL PASS TO THE UPPER OHIO VALLEY. FOR NOW HAVE A
CHANCE OF RAIN AND SNOW SHOWERS LATE SATURDAY INTO SUNDAY.
A CLIPPER TYPE SYSTEM MAY DEVELOP EARLY NEXT WEEK IN THE EVOLVING
NORTHWESTERLY UPPER FLOW. HOWEVER, PRECIPITATION PROBABILITY TO
SMALL TO MENTION. SO MAINTAINED MAINLY CLOUDY CONDITIONS, WHICH LED
TO LOW TEMPERATURES WARMER THAN NORMAL.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
PER RECENT SURFACE AND RADAR DATA AND HRRR MODEL OUTPUT, EXPECT LAKE
EFFECT SNOW BANDS TO CAUSE FLIGHT CONDITIONS TO DETERIORATE TO IFR
AT TIMES THROUGH 00Z. NORTHWEST SURFACE WINDS CAN GUST TO 25 KTS.
RECENT NAM MODEL PROFILES SHOW A LOWERING SUBSIDENCE INVERSION
TOWARD 00Z, THAT WILL CAP THE LAKE EFFECT INSTABILITY THIS EVENING.
HENCE EXPECT NO WORSE THAN MVFR RESTRICTIONS EARLY TONIGHT WITH VERY
LIGHT SNOW SHOWERS. THEN DISSIPATING STRATOCUMULUS SHOULD YIELD
MAINLY VFR BY LATE TONIGHT.
FAST-MOVING EASTBOUND CLIPPER TYPE LOW PRESSURE SYSTEM MAY PRODUCE
SNOW SHOWERS AND POSSIBLY MVFR RESTRICTIONS WEDNESDAY AFTERNOON.
OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY...
EXPECT MAINLY VFR THURSDAY INTO SATURDAY. POSSIBLE RESTRICTIONS WITH
MIXED PRECIPITATION SATURDAY NIGHT INTO SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR OHZ040-
041-050.
PA...LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
PAZ007>009.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ074-
076.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
PAZ013>016-020>023-029-031-073-075.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR WVZ023-
041.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
WVZ001>003-021-022.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1219 PM EST TUE JAN 3 2012
.SYNOPSIS...
NORTHWEST WINDS ACROSS THE GREAT LAKES WILL CONTINUE TO BRING
SNOW SHOWERS THIS AFTERNOON AND QUITE COLD TEMPERATURES THROUGH
TONIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
MADE MINOR ADJUSTMENTS TO POPS...EXPECTED SNOW AMOUNTS AND
TEMPERATURES BASED ON RADAR TRENDS AND SURFACE OBSERVATIONS.
LAKE EFFECT SNOW BANDS WILL PERSIST ACROSS PARTS OF WESTERN
PENNSYLVANIA AND EAST CENTRAL OHIO THIS AFTERNOON DUE TO
TRAJECTORY OF NORTHWEST FLOW OFF THE GREAT LAKES.
HAVE MAINTAINED HEADLINES AND WILL CONTINUE TO ISSUE SPECIAL
WEATHER STATEMENTS AS NEEDED FOR OTHER PERSISTING SNOW BANDS THAT
DEVELOP.
NAM MODEL PROFILES SHOW CAPPING INVERSION LOWERING TO 5 KFT AGL
TOWARD EVENING WHICH SHOULD REDUCE COVERAGE AND INTENSITY OF
REMAINING SNOW SHOWERS.
TEMPERATURES WILL BE NEARLY STEADY THIS AFTERNOON AS COLD ADVECTION
CONTINUES. WINDS WILL BE GUSTY FORM THE NORTHWEST WITH WINDS
CHILLS IN THE SINGLE DIGITS. SURFACE RIDGE WILL BEGIN TO DAMPEN
SNOW SHOWERS THIS EVENING WITH TEMPERATURES IN THE TEENS TO SINGLE
DIGITS IN THE RIDGES. WIND CHILLS TONIGHT WILL BE BORDERLINE FOR
AN ADVISORY IN THE RIDGES AND WILL BE MONITORED.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
ON WEDNESDAY AND WEDNESDAY NIGHT...A SHORTWAVE TROUGH WILL
QUICKLY SWING SOUTHEAST ACROSS THE UPPER OH VALLEY BRINGING LOW
CHANCES FOR SNOW SHOWERS AS BEST DYNAMICS AND MOISTURE REMAIN
NORTH OF REGION. THURSDAY SHOULD BE MAINLY DRY AS A WEAK RIDGE
MOVES OVER THE REGION. TEMPERATURES WILL RECOVER WELL INTO THE 30S
THURSDAY AFTERNOON.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
LATEST MODELS SHOW CLIPPER MOVING ACROSS THE GREAT LAKES THURSDAY
NIGHT AND FRIDAY REMAINING FARTHER NORTH THAN PREVIOUS RUNS SO
HAVE GONE WITH A DRY FORECAST. WEAK FRONT WILL ARRIVE FRIDAY
NIGHT...WITH BEST CHANCE OF SHOWERS ON SATURDAY. SOME MODEL
DISAGREEMENT FOR SUNDAY INTO MONDAY...WITH DETERMINISTIC MODELS
INDICATING A CYCLONE DEVELOPING ACROSS THE SOUTHEASTERN UNITED
STATES (AND CLIPPING OUR SOUTHERN COUNTIES)...WHILE ENSEMBLES
GENERALLY KEEP CONDITIONS DRY. WITH MODELS STILL SHOWING SOME
INDICATION OF PRECIP...HAVE DECIDED TO KEEP SLIGHT CHANCE POPS FOR
THE SOUTHERN COUNTIES. HAVE ALSO ADDED SOME POPS NORTH FOR LAKE
EFFECT. TEMPERATURES SHOULD BE ABOVE NORMAL FRIDAY AND
SATURDAY...THEN MODERATING FOR SUNDAY AND MONDAY.
&&
.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND RADAR DATA AND HRRR MODEL OUTPUT, EXPECT LAKE
EFFECT SNOW BANDS TO CAUSE FLIGHT CONDITIONS TO DETERIORATE TO IFR
AT TIMES THIS AFTERNOON. NORTHWEST SURFACE WINDS CAN GUST TO 25 KTS.
RECENT NAM MODEL PROFILES CONTINUE TO SHOW A LOWERING SUBSIDENCE
INVERSION LATE THIS AFTERNOON THAT WILL CAP THE LAKE EFFECT
INSTABILITY BY EVENING. HENCE EXPECT NO WORSE THAN MVFR RESTRICTIONS
LATE AFTERNOON AND MAINLY VFR TONIGHT.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
LOW PRESSURE MOVING ACROSS THE GREAT LAKES MAY BRING SNOW SHOWERS
AND RESTRICTIONS LATE WEDNESDAY. EXPECT MAINLY VFR THURSDAY INTO
SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR MDZ001.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ013>016-022-023-073-075.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR PAZ074-
076.
LAKE EFFECT SNOW WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ007>009.
WV...WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR WVZ023-
041.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
349 PM EST TUE JAN 3 2012
.SHORT TERM /TONIGHT AND WED/...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THE NEXT SHORTWAVE TROF OF
INTEREST HEADING SE THRU MANITOBA AND THE DAKOTAS. IMPRESSIVE
WARMING IS NOTED AHEAD OF FEATURE. 850MB TEMPS AT KBIS/KABR/KINL
HAVE JUMPED FROM -1/-6/-15C RESPECTIVELY AT 00Z TUE TO 11/9/-9C AT
12Z. STRONG WAA HAS YET TO YIELD ANY PCPN. ONLY SOME MID AND HIGH
CLOUDS ARE NOTED. AS SHORTWAVE CONTINUES ESE...DON`T ANTICIPATE ANY
PCPN TO DEVELOP IN ONGOING STRONG WAA GIVEN OVERALL RELATIVELY DRY
ENVIRONMENT SHOWN ON THIS MORNINGS REGIONAL SOUNDINGS. THERE IS JUST
ENOUGH LINGERING OVERWATER INSTABILITY TO GENERATE SOME -SHSN OFF
THE LAKES UNDER SYNOPTIC FORCING. WIND SHOULD HAVE ENOUGH SOUTHERLY
COMPONENT TO WARRANT A MENTION OF -SHSN OVER THE E THIS EVENING...
AND ALSO OVER THE KEWEENAW LATER THIS EVENING AND OVER THE NE FCST
AREA WED MORNING AS SW WINDS VEER WNW. OTHERWISE...CONCERN AFTER
FROPA IS POTENTIAL FOR -FZDZ AS MIDLEVELS SHARPLY DRY WHILE MODELS
INSIST THAT A SHALLOW MOIST LAYER (2-3KFT THICK) MATERIALIZES. TEMPS
WITHIN THE SHALLOW MOIST LAYER ARE WARMER THAN -10C...SUGGESTING NO
ICE NUCLEATION. SATELLITE/UPSTREAM OBS HAVE YET TO SHOW ANY LOW
CLOUD DEVELOPMENT. HOWEVER...NOSE OF HIGHER SFC DWPTS WELL INTO THE
20S INTO SRN MANITOBA/ERN ND IS SUPPORTIVE OF A POTENTIAL LOW-CLOUD
DECK DEVELOPING AS THE MOISTURE ADVECTS INTO COLDER AIRMASS OVER THE
AREA TONIGHT. HAVE THUS INCLUDED A MENTION OF -FZDZ IN THE WNW WIND
UPSLOPE AREAS OVER WRN UPPER MI LATE EVENING INTO THE MORNING HRS
AND OVER THE NE FCST AREA WED. CONFIDENCE IS LOW.
CLOSELY FOLLOWED REGIONAL GEM FOR TEMP TRENDS TONIGHT. SOME AREAS...
ESPECIALLY W AND N...WILL SEE MINS EARLY THIS EVENING WITH TEMPS
SLOWLY RISING THRU THE NIGHT. MAX TEMPS IN THE UPPER 20S AROUND 30F
SHOULD BE THE RULE WED.
.LONG TERM /WED NIGHT THROUGH NEXT TUESDAY/...
WEAK SHORTWAVE WILL BE SLIDING THROUGH THE NW FLOW AT THE START OF
THE PERIOD AND WILL LEAD TO SOME MID CLOUDS OVER MUCH OF THE CWA.
LARGE DIFFERENCES IN H850 TEMPS BETWEEN 12Z NAM AND 06Z GFS...WITH
THE NAM AROUND -6C AND GFS AROUND -9C OVER THE ERN LK. 12Z GEM AND
00Z ECMWF ARE A LITTLE CLOSER TO THE GFS THAN THE NAM. THESE
DIFFERENCES PRODUCE UNCERTAINTY IN LK EFFECT CHANCES AND WILL JUST
MENTION FLURRIES OVER THE NW WIND FAVORED AREAS E OF MUNISING WED
NIGHT. AS SHORT TERM DISCUSSION MENTIONED...THERE COULD BE SOME
DRIZZLE INSTEAD...BUT FELT CHANCES WERE TOO LIMITED TO MENTION.
FLATTENING UPPER RIDGE ON THURS WILL BACK H850-500 WINDS TO THE WEST
AND PRODUCE BROAD WAA OVER THE UPPER GREAT LKS. WITH MOISTURE
STREAMING THROUGH THE UPPER FLOW...THINK THERE WILL BE SOME MID
CLOUDS OVER THE AREA THURS INTO THURS NIGHT...BUT DRIER LLVLS WILL
LIMIT PCPN EVEN WITH THE INCREASING WAA. SFC LOW DEVELOPING OVER THE
CANADIAN ROCKIES ON THURS IN RESPONSE TO SHORTWAVE MOVING THROUGH
THE NRN STREAM WILL SHIFT SE TOWARDS LK WINNIPEG BY 00Z FRI. DEEPEST
MOISTURE AND STRONGEST WAA WILL OCCUR OVER SRN ONTARIO AND NRN LK
SUPERIOR ALONG THE DEVELOPING WARM FRONT THURS AFTN INTO THE
EVENING...SO WILL CONTINUE CHANCE PCPN MENTIONS THERE.
WITH THE SFC LOW SLIDING THROUGH SRN ONTARIO THURS NIGHT AND
FRI...SW HALF OF THE AREA WILL BE UNDER DRY WARM MID LVL AIR /H850
TEMPS RISING TOWARDS 2-3C BY 12Z FRI/. MODELS CONTINUE TO SHOW
MOISTURE TRAPPED BELOW THE H900 INVERSION ON THURS NIGHT INTO THE
FIRST PART OF FRI...WHICH COULD LEAD TO BROAD LOWER STRATUS AT LEAST
ON THURS NIGHT. NOT ENTIRELY CONF ON AMNT/COVERAGE OF LOW
CLOUDS...SO WILL CONTINUE PARTLY CLOUDY SKIES OVER THE SW HALF OF
THE AREA. INCREASING WINDS...DRIER AIR...AND WEAKENING INVERSION ON
FRI SHOULD DIMINISH CLOUD COVERAGE OVER THE SW HALF. THE REST OF THE
AREA WILL BE ON THE EDGE OF THE MID CLOUDS FROM THE SYSTEM OVER THE
N. WITH AREA IN WARM SECTOR...EXPECT ABOVE NORMAL TEMPERATURES
ACROSS THE AREA ON FRI. WILL CONTINUE UPPER 30S FCST...BUT COULD SEE
SOME LOWER 40S OVER THE SCNTRL...WHERE THE WARMEST LLVL AIR WILL BE
LOCATED.
DAYS 4 THROUGH 7 /FRI NIGHT THROUGH NEXT TUESDAY/...
THE SFC LOW SHIFTING E THROUGH SERN ONTARIO AT THE START OF THE
EXTENDED PERIOD...DROPPING A COLD FRONT WILL SE ACROSS THE CWA FRI
NIGHT INTO SAT. DEEP MOISTURE/FORCING CONTINUE TO APPEAR LIMITED AND
WILL CONTINUE ONLY LOW END CHANCE POPS WITH THE PASSAGE OF THE
FRONT. THE COLD FRONT THAT DROPS ACROSS THE AREA LOOKS TO GET HUNG
UP OVER UPPER MI AND NRN WI ON SAT NIGHT DUE TO LIMITED COLD AIR
BEHIND TO GIVE IT A PUSH. ADDITIONAL LLVL MOISTURE FROM THE UPPER
TROUGH ROTATING THROUGH AND H850 TEMPS GRADUALLY FALLING TOWARDS
-14C BY SUN MORNING SHOULD LEAD TO A SLOWLY EXPANDING AREA OF LIGHT
LES SAT NIGHT INTO SUN...MAINLY FOR NW WIND LOCATIONS. LACK OF COLD
AIR GETTING FORCING INTO THE DGZ IS THE MAIN LIMITING FACTOR...SINCE
INVERSION HEIGHTS WILL INITIALLY BE AROUND 6KFT AND PLENTY OF LLVL
MOISTURE. DID BUMP POPS UP SOME FOR FAVORED LOCATIONS...BUT KEPT
THEM IN THE LOW CHANCE CAT DUE TO LIMITED ACCUM POTENTIAL.
HIGH PRESSURE WILL BUILD INTO LK SUPERIOR ON SUN AS UPPER TROUGH
SHIFTS E. DRIER AIR AND SUBSIDENCE WILL LEAD TO LOWERING INVERSION
HEIGHTS AND SHOULD TAPER OFF LES IN THE EVENING. UPPER GREAT LKS
REGION SHIFTS BACK SLIGHTLY NW FLOW ALOFT AS THE RIDGE OVER THE WRN
CONUS FLATTENS. THIS WILL ALLOW WARMER H850 TEMPS TO INVADE THE
UPPER GREAT LKS REGION AND KEEP THE NRN STREAM WAVES RUNNING ALONG
AND JUST N OF THE U.S./CANADIAN BORDER. EXTENDED MODELS CONTINUING
TO SHOW WAVE AFFECTING SRN ONTARIO ON MON...WHICH MAY PUSH SOME PCPN
OVER THE NE HALF OF THE CWA...OTHERWISE THE FAIRLY QUIET AND ABOVE
NORMAL TEMP PATTERN OF WINTER CONTINUES.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
VFR CONDITIONS WILL PREVAIL INTO THE EVENING HRS AT KIWD/KCMX/KSAW
UNDER RELATIVELY DRY AIRMASS PER MORNING SOUNDINGS. WITH SFC HIGH
PRES RIDGE OVER THE AREA EXITING TO THE E... A STRENGTHENING S WIND
WILL DEVELOP AS PRES GRADIENT TIGHTENS BTWN THE DEPARTING HI AND A
DISTURBANCE/AREA OF PRES FALLS PASSING THRU NRN ONTARIO. AS IS
TYPICAL...THE STRONGEST S WINDS SHOULD IMPACT KIWD AND KSAW WITH
GUSTS AOA 25 KTS. SHOULD WINDS DECOUPLE SUFFICIENTLY THIS EVENING...
LLWS WILL BE POSSIBLE. AS THE ONTARIO DISTURBANCE MOVES FARTHER TO
THE E TONIGHT...A LOW PRES TROF WILL SWING ACROSS UPPER MI. AS THE
FLOW VEERS TO THE WNW...EXPECT LOW CLDS/MVFR CIGS AND PERHAPS SOME
-FZDZ OR -SN TO DEVELOP WHERE THIS FLOW UPSLOPES AT KCMX/KIWD.
CONFIDENCE IS LOW. DOWNSLOPE NATURE OF THE WIND AT KSAW WILL LIMIT
THIS POTENTIAL THERE.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
PERIOD OF S TO SW GALES ARE EXPECTED LATE AFTN/EVENING OVER MUCH OF
LAKE SUPERIOR AS PRES GRADIENT TIGHTENS BTWN DEPARTING HIGH PRES AND
APPROACHING LOW PRES TROF. HEALTHY AREA OF PRES FALLS (CURRENTLY
8MB/3HR JUST NW OF LAKE SUPERIOR) SHOULD BE SUFFICIENT TO NUDGE
WINDS TO GALE FORCE AS PRES FALLS SHIFT EASTWARD THIS EVENING. SW
WIND WILL VEER TO THE NW LATER TONIGHT WED...WITH SPEEDS UP TO 25-30
KTS. AS AN AREA OF HIGH PRES MOVES INTO ONTARIO THU...WINDS OVER THE
LAKE WILL DIMINISH BLO 20KT. LOOK FOR A STRONGER WESTERLY WIND OF
25-30 KTS TO RETURN FRI FOLLOWING THE PASSAGE OF ANOTHER LOW PRES
SYSTEM THRU ONTARIO.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ266-267.
GALE WARNING UNTIL 10 PM EST /9 PM CST/ THIS EVENING FOR LSZ162-
263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1122 AM EST TUE JAN 3 2012
.SYNOPSIS...
THE COLDEST AIR SO FAR THIS WINTER SEASON WILL CONTINUE TO SWEEP
SOUTHEAST ACROSS THE GREAT LAKES AND INTO PENNSYLVANIA TODAY THROUGH
WEDNESDAY. FREQUENT LAKE EFFECT SNOW SHOWERS AND SOME HEAVY SQUALLS
WILL BE CONCENTRATED ACROSS THE NORTHWESTERN MOUNTAINS AND LAUREL
HIGHLANDS. SNOW SHOWERS OF LESSER INTENSITY AND BRIEF SQUALLS WILL
DRIFT INTO THE NORTHERN AND CENTRAL MOUNTAINS AT TIMES. A WARMUP TO
ABOVE NORMAL TEMPERATURES IS EXPECTED LATER THIS WEEK BEFORE ANOTHER
SURGE OF COLD AIR APPROACHES FOR LATE IN THE UPCOMING WEEKEND. THE
COLD AIR...WESTERLY FLOW AND WARM LAKES COULD PRODUCE MORE LAKE
EFFECT SNOW ACROSS WESTERN PENNSYLVANIA NEXT MONDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WILL CANCEL POTTER WINTER WEATHER ADVISORY...WITH THE MAIN FOCUS
ON THE DOMINANT SNOWBAND WITH LAKE HURON CONNECTION WHICH HAS
INTENSIFIED AGAIN IN THE PAST HOUR. WILL EXTEND THE WEST CENTRAL
MOUNTAIN WINTER WEATHER ADVISORY THROUGH 00Z TONIGHT...COINCIDING
WITH EXPIRATION TIMES FOR THE NORTHWEST MOUNTAIN AND LAUREL
HIGHLAND WARNINGS.
DOMINANT SNOWBAND WITH LAKE HURON CONNECTION CONTINUES TO WAGGLE
SW/NE OVER THE NORTHWEST MOUNTAINS AND LAUREL HIGHLANDS THIS
MORNING. THE BAND HAS WEAKENED EARLY THIS MORNING WITH
VISIBILITIES IN ONLY A FEW PLACES AS LOW AS 3/4 MILE AT THIS TIME.
LAPSE RATES REMAIN STEEP THROUGH THIS AFTERNOON AS THE COLDEST 850
MB AIR TRACKS ACROSS NORTHEAST PA WHILE A COMPACT SHORTWAVE TRACKS
THROUGH THE LAURELS AND INTO NO VA. THIS SHOULD KEEP SOME
ACCUMULATING SNOW GOING ACROSS THE LAURELS AND SNOWBELT REGION
THROUGH THIS EVENING.
HIGH RESOLUTION HRRR AND NAM12 INDICATE ORGANIZATION AND INTENSITY
OF SNOW BANDS DECREASING SIGNIFICANTLY AFTER 20Z...AS INVERSION
HEIGHTS START TO CRASH AND BOUNDARY LAYER TEMPS MODERATE. HOWEVER...
AS PREVIOUS SHIFT NOTED...NAM BUFKIT SHOWS A CROSS-HAIR SIGNATURE
OF STRONG UVVEL WITHIN THE FAVORABLE THERMAL RIBBON FOR DENDRITIC
SNOW GROWTH. THIS SHOULD BRING MOST AREAS OF CENTRAL PA ANOTHER
COATING TO ONE INCH OF SNOW...WITH A COUPLE INCHES OR MORE OF NEW
FLUFFY /WIND-WHIPPED SNOW FALLING ACROSS THE NW MTNS AND SNOWBELT
OF WARREN COUNTY.
CONTINUED DEEP-LAYER COLD ADVECTION WILL KEEP TEMPS STEADY OR SLOWLY
FALLING...IN THE TEENS TO LOWER 20S ACROSS THE CENTRAL AND WESTERN
COUNTIES...AND MID TO UPPER 20S IN THE SUSQ VALLEY. WIND CHILLS
WILL FREQUENTLY DIP BELOW ZERO TODAY ACROSS THE NRN AND WRN
MTNS...AND HOLD IN THE SINGLE DIGITS TO LOWER TEENS ELSEWHERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
WARMER AIR ALOFT MOVES IN TONIGHT DIMINISHING THE SNOW SHOWERS
RATHER QUICKLY. STEEP LLVL LAPSE RATES...WILL COMBINE WITH BACKING
BLYR WINDS AND WEAK ISENTROPIC UPGLIDE WITHIN THE 275-285K THETA
CHANNEL TO MAINTAIN BKN-OVC/SHALLOW STRATO CU CLOUDS AND SOME
INTERMITTENT VERY LIGHT SNOW OR FLURRIES ACROSS THE WRN MTNS
TONIGHT...WHILE PARTLY CLOUDY SKIES ARE ANTICIPATED ELSEWHERE.
COLDEST TEMPS OF THE WINTER SEASON SO FAR IN MANY LOCATIONS WILL
OCCUR TONIGHT. MINS WILL BE IN THE 5-10F RANGE ACROSS THE NW HALF TO
TWO-THIRDS OF THE CWA...WITH LOWER TEENS THROUGHOUT THE SE ZONES.
THE NEXT WEAK...CLIPPER SYSTEM SLIDES SE FROM THE GLAKES REGION
WEDNESDAY LEADING TO INCREASING CLOUDS AND PERHAPS A PERIOD OF LIGHT
SNOW...OR MORE LIKELY SNOW SHOWERS /MAINLY ACROSS THE NW HALF OF
PENN/. LIGHT ACCUMS OF A COATING TO ONE INCH WILL BE POSSIBLE OVER
THE NW MTNS.
MAX TEMPS WED WILL BE 5 TO 8 DEG F WARMER ACROSS THE CENTRAL AND NW
ZONES AND AT LEAST A FEW DEG F HIGHER THROUGHOUT THE LOWER SUSQ
VALLEY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE SECOND HALF OF THIS WEEK FEATURES GRADUALLY RISING MID/UPPER
LEVEL HEIGHTS AND A TREND TOWARD ZONAL FLOW. ASIDE FROM SOME
/LIGHTER/ LES AND OROGRAPHIC SNOW SHOWERS ACROSS THE NW MTNS AND
LAURELS WEDNESDAY NIGHT THROUGH MIDDAY THURSDAY...DRY WEATHER WITH A
RETURN TO ABOVE NORMAL TEMPS WILL FOLLOW FOR FRIDAY AND SATURDAY AS
AN POTENT LOW PRESSURE AREA SCOOTS BY ACROSS SOUTHERN CANADA.
A COLD FRONT /EXTENDING SOUTH FROM THE SERN CANADA LOW/ MAY LINK UP
WITH AN INVERTED LLVL TROUGH EXTENDED NORTH FROM THE TENN VALLEY OR
SRN APPALACHIANS TO BRING INCREASING CLOUDS AND PERHAPS SOME LIGHT
SNOW LATER IN THE WEEKEND.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
LAKE EFFECT SNOW BANDS CONTINUE ACROSS THE NW HALF OF THE REGION
IN STRONG NW FLOW. STRONGEST BAND THROUGH MID MORNING WILL BE
LOCATED IN THE VICINITY OF KJST-KAOO...AND WITH INTENSITIES NEAR
40 DBZ IT WILL PRODUCE IFR CONDITIONS AS IT SLOWLY DRIFTS SOUTH
THROUGH MID MORNING. ELSEWHERE...LOCAL REDUCTIONS REMAIN POSSIBLE
IN LESS INTENSE SNOWBANDS IN THE NORTHERN TIER AND CENTRAL
MTNS...THOUGH PREVAILING CONDITIONS WILL BE MVFR/VFR.
CIGS SHOULD LIFT TO VFR IN MOST PLACES BY LATE MORNING AHEAD OF
ONE LAST SHORTWAVE SLIDING DOWN BACK SIDE OF TROUGH. THIS S/W
COULD BRING ADDITIONAL LIGHT SNOW TO NW MTNS AND LAURELS LATER
THIS AFTERNOON...BUT INTENSITY SHOULD REMAIN LIGHT WITH MVFR
RESTRICTIONS. OTHERWISE...THIS AFTERNOON AND OVERNIGHT WILL SEE
IMPROVING CONDITIONS AS SURFACE RIDGE BUILDS IN...KEEPING
CONDITIONS VFR THROUGH WED.
GUSTY NORTHWEST SURFACE WINDS TO 25 KTS WILL CONTINUE DURING THE
DAY TODAY...BEFORE GRADUALLY DIMINISHING THIS EVENING AND
ESPECIALLY OVERNIGHT.
OUTLOOK...
TUE...OCNL MVFR IN -SN NW. OTHERWISE PRIMARILY VFR WITH ISOLD
MVFR IN -SHSN.
WED...VFR.
WED NIGHT-SAT...PRIMARILY VFR. OCNL MVFR POSS IN NW MTNS/LAURELS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
PAZ004-005.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ024-
033.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ010-
011-017.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...LAMBERT/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
244 PM CST TUE JAN 3 2012
.SHORT TERM...TONIGHT AND WEDNESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE SHIFTING EAST OVER THE CENTRAL GREAT LAKES THIS
AFTERNOON...IN RESPONSE TO MID-LEVEL HEIGHT FALLS OCCURRING OVER THE
NORTHERN PLAINS AHEAD OF A SHORTWAVE TROUGH. AHEAD OF THIS
TROUGH...MID AND HIGH CLOUDS ARE ON THE INCREASE ACROSS THE REGION.
A WARM FRONT LIES FURTHER UPSTREAM ACROSS THE PLAINS BUT THE RAOB
NETWORK SHOW AMPLE DRY AIR IN THE MID-LEVELS AND A LACK OF PRECIP.
AS THE SHORTWAVE MOVES ACROSS THE REGION TONIGHT...CONCERNS FOCUS ON
SMALL POP CHANCES AND TEMPS.
TONIGHT...SHORTWAVE TROUGH OVER THE NORTHERN PLAINS WILL SLIDE
SOUTHEAST AND BECOME ELONGATED. COMBINED WITH LIFT OVER A
H850 WARM FRONT...THE WAVE HAS SOME DECENT FORCING WITH IT. BUT
SOUNDINGS UPSTREAM REMAIN PRETTY DRY IN THE MID-LEVELS...AND CANNOT
FIND ANY PRECIP REPORTED IN THE OBS OVER SOUTHERN MANITOBA AND
SASKATCHEWAN. AS A RESULT...WILL REMOVE THE LIGHT SNOW SHOWER AND
FLURRY MENTION. WINDS WILL BE STRENGTHENING OUT OF THE SOUTHWEST
AHEAD OF THE SHORTWAVE AND MAY FIND IT DIFFICULT FOR WINDS TO
DECOUPLE. WITH THE BKN MID AND HIGH CLOUD COVER...TEMPS WILL BE
SIGNIFICANTLY WARMER THAN LAST NITE. LOWS RANGING THROUGH THE TEENS.
WEDNESDAY...POTENT 150KT JET STREAK WILL DIVE SOUTHEAST OVER THE
WESTERN GREAT LAKES IN THE AFTERNOON. LEFT FRONT QUAD OF THE JET
WILL PASS TO THE EAST OF THE REGION...KEEPING ANY UPPER DIVERGENCE
FROM CREATING LIGHT PRECIP. WILL STILL SEE INCREASING MID AND HIGH
CLOUDS (ABOVE 9KFT OR SO) AFTER A PERIOD OF MOSTLY CLEAR TO PARTLY
CLOUDY CONDITIONS IN THE MORNING. TEMPS WILL CONTINUE TO REBOUND TO
THE UPPER 20S AND LOWER 30S.
.LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. OVERALL MAINLY
A QUIET AND RELATIVELY MILD PATTERN DURING THIS PERIOD.
UPPER HEIGHTS BUILD WEDNESDAY NIGHT INTO THURSDAY AS A WEAK
SURFACE HIGH RIDGE SLIDES OVER. UPPER FLOW BREAKS DOWN BRIEFLY AS
A BROAD UPPER TROUGH WORKS OVER THE NORTHERN US REGION. A PERIOD
OF WARM AIR ADVECTION AHEAD OF THIS UPPER TROUGH WILL BRING A NEAR
STEADY TEMPERATURE TREND TO THE AREA THURSDAY NIGHT. AN ASSOCIATED
SURFACE LOW PRESSURE SYSTEM TRACKING OVER THE NORTHERN GREAT
LAKES REGION WILL THEN SLIDE A WEAK COLD FRONT OVER THE STATE ON
FRIDAY. ANY PCPN WILL BE MINIMAL AND CONFINED WELL NORTH CLOSER TO
THE SYSTEM ALONG WITH A PERIOD OF CAA OVER LAKE SUPERIOR.
WHILE SURFACE RIDGING SETTLES BACK INTO THE AREA FOR THE WEEKEND
WITH THE WESTERN STATES UPPER RIDGE BUILDING...A CONTINUED PARADE
OF WEAK MID LEVEL SUBTLE SHORT WAVES ARE PROGGED TO DROP OVER THE
AREA FOR THE WEEKEND. AS HAS BEEN THE CASE LATELY...LITTLE
MOISTURE AVAILABLE WITH THESE PACIFIC ORIGIN SYSTEMS.
MEDIUM RANGE RUNS FLATTEN THE WESTERN RIDGE FOR THE START OF THE
NEW WEEK WITH BUILDING UPPER HEIGHTS FOR THE FORECAST AREA. ANOTHER
WARMING TREND IS ANTICIPATED WITH THE RETURN SOUTHWEST TO WEST
FLOW AS THE MAIN LOW PRESSURE SYSTEM PASSES WELL NORTH OF THE
GREAT LAKES REGION.
WILL GO ABOVE GUIDANCE NUMBERS THURSDAY NIGHT AS WELL AS NEXT WEEK
DUE TO THE WARM AIR ADVECTION. THE AMOUNT OF WARM UP WILL BE
TRICKY DUE TO THE LACK OF SNOW COVER WEST TO SOUTHWEST OF THE
AREA...BUT STILL NEED TO FACTOR IN A COLD GROUND/INVERSION AND
LOW SUN ANGLE...NOT TO MENTION SKY CONDITION.
&&
.AVIATION...SW WINDS WILL STRENGTHEN LATE THIS AFTERNOON AND THROUGH
THE EVENING JUST ABOVE THE INVERSION TO 35-40KTS. AS A
RESULT...KEPT A LLWS MENTION IN ALL TAFS. OTHERWISE...VFR
CONDITIONS PREVAILING THROUGH THE TAF PERIOD WITH ONLY MID AND HIGH
CLOUDS OVERHEAD.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/TDH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
237 PM CST TUE JAN 3 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY
237 PM CST TUE JAN 3 2012
MAIN FORECAST CONCERNS ARE ON ANY CHANCES FOR PRECIPITATION
TONIGHT...THEN THE ABOVE NORMAL TEMPERATURE PATTERN THROUGH FRIDAY.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING PRETTY MUCH DOMINATING THE WESTERN TWO THIRDS OF THE
U.S. INTO SOUTHERN CANADA...EXCLUDING A POSITIVELY TILTED SHORTWAVE
TROUGH ENTERING THE WESTERN DAKOTAS...WHILE DEEP TROUGHING EXISTED
ALONG THE EAST COAST. STRONG WARM ADVECTION HAS BEEN OCCURRING AHEAD
OF THE WESTERN DAKOTAS SHORTWAVE...NOTED BY 850MB TEMPS THAT ROSE
NEARLY 15C AT ABR AND 8C AT MPX BETWEEN THE 00Z AND 12Z SOUNDINGS.
BOTH SOUNDINGS DEPICT A STRONG INVERSION...ESPECIALLY AT ABR...AND
IS TO BE EXPECTED THIS TIME OF YEAR WITH SHALLOW COLD AIRMASSES MORE
DOMINANT. DAYTIME MIXING THROUGH HIGH CLOUDS AHEAD OF THE SHORTWAVE
TROUGH HAS ALLOWED SURFACE TEMPERATURES TO CLIMB INTO THE 20S OVER
THE FORECAST AREA...AND INTO THE 30S OVER SOUTHWEST MN INTO WESTERN
IOWA. AIR ACROSS THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI
RIVER VALLEY WAS QUITE DRY AS WELL...WITH DEWPOINT DEPRESSIONS OFF
THE 12Z GRB...MPX AND ABR SOUNDINGS OF 10C OR MORE FROM 950-650MB.
AT THE SURFACE...A WARM FRONT WAS LOCATED ALONG THE DAKOTAS/MN
BORDER...WITH BREEZY SOUTH WINDS AHEAD OF IT INTO THE FORECAST AREA.
BEHIND THE FRONT...READINGS ARE IN THE 40S AND 50S OVER THE DAKOTAS.
TONIGHT AND WEDNESDAY...MODELS PROG THE POSITIVELY TILTED SHORTWAVE
TROUGH OVER THE WESTERN DAKOTAS TO MOVE SOUTHEAST ACROSS THE
FORECAST AREA BETWEEN 06-12Z TONIGHT. IN ITS WAKE...40-70 METER
HEIGHT RISES ARE EXPECTED FOR WEDNESDAY AT 500MB WHILE ANOTHER WEAK
SHORTWAVE DROPS SOUTHEAST INTO UPPER MICHIGAN. MAIN CONCERN IS
WHETHER OR NOT THE SHORTWAVE TROUGH CAN PRODUCE PRECIPITATION
TONIGHT. CERTAINLY THERE ARE DECENT 500MB HEIGHT FALLS...60-90
METERS...INDICATIVE OF THE DYNAMIC FORCING. HOWEVER...ISENTROPIC
LIFT PLOTS ON 285K-300K SURFACES SHOW LITTLE OR NO LIFT...AS WELL AS
PLENTY OF DRY AIR BETWEEN 850-600MB. THEREFORE...NOT EXPECTING ANY
PRECIPITATION WITH THE TROUGH. AFTER THIS...THE ONLY CONCERN IS
CLOUD COVER. THERE MAY BE SOME LOW CLOUDS IN THE WAKE OF THE
TROUGH...BUT MOST OF THESE ARE EXPECTED TO STAY NORTH AND EAST OF
THE AREA. ADDITIONAL MID/HIGH CLOUD COVER LOOKS TO COME IN WEDNESDAY
AFTERNOON WITH THE NEXT SHORTWAVE...BUT MOST OF THESE CLOUDS SHOULD
STAY ALONG OR NORTHEAST OF I-94. REGARDING TEMPERATURES...LOWS
TONIGHT WILL END UP MUCH WARMER THAN LAST NIGHT...AIDED BY CLOUD
COVER AND THE PASSAGE OF THE WARM FRONT. PREVIOUS FORECAST LOWS SEEM
REASONABLE WHICH ONLY SHOW ABOUT A 5 DEGREE TEMPERATURE DROP FROM
CURRENT READINGS. GIVEN A WARMER START FOR TOMORROW AND 925MB TEMPS
CLIMBING TO -2C TO +1C...HIGHS SHOULD EASILY REACH THE 30S IN MOST
LOCATIONS. A FEW LOCATIONS IN NORTHEAST IOWA COULD EVEN REACH 40.
WEDNESDAY NIGHT THROUGH FRIDAY...UPPER LEVEL TROUGHING...CURRENTLY
SEEN ON WATER VAPOR OVER THE NORTHEAST PACIFIC...IS PROGGED TO
MOSTLY EJECT OUT AND DROP DOWN INTO THE NORTHERN PLAINS AND SOUTH
CENTRAL CANADA COME FRIDAY IN A POSITIVELY TILTED FORM. AS THE
TROUGH HEADS EAST...A SURGE OF PACIFIC AIR ADVECTS EAST WITH IT INTO
THE FORECAST AREA...WARMED UP EVEN MORE IN RESPONSE TO DOWNSLOPING
OFF THE ROCKIES. 850MB TEMPS CLIMB FROM 0-2C AT 00Z THURSDAY TO AS
MUCH AS 8-12C AT 00Z FRIDAY. SOME COOL DOWN IN 850MB TEMPS IS
FORECAST FOR FRIDAY WITH READINGS DROPPING FROM 6-10C AT 12Z FRIDAY
TO -2 TO +2C BY 00Z SATURDAY...ALL IN RESPONSE TO THE APPROACHING
TROUGH. ALTHOUGH A LOT OF THIS WARMING IS TAKING PLACE ALOFT...AGAIN
AS TO BE EXPECTED THIS TIME OF YEAR WITH A LOWER SUN ANGLE AND
SHORTER DAY LENGTH...THE LACK OF SNOW COVER WILL HELP WITH MIXING.
HOW WARM WE ACTUALLY GET IS THE BIG QUESTION. FIRST OFF...THIS TIME
PERIOD WILL END UP DRY DUE TO THE SERIOUS LACK OF MOISTURE BELOW
10000 FT AS SEEN ON MODEL SOUNDINGS. NOW REGARDING CLOUD COVER. A
STREAM OF MID-HIGH CLOUDS OVER WISCONSIN LATE WEDNESDAY LOOKS TO
PUSH SLOWLY EAST THROUGH THURSDAY...IN RESPONSE TO THE BUILDING
HEIGHTS ALOFT. ANOTHER SURGE OF MID/HIGH CLOUDS LOOKS TO CROSS THE
ENTIRE FORECAST AREA THURSDAY NIGHT...IN THE WESTERLY FLOW AHEAD OF
THE SHORTWAVE TROUGH...BUT THESE APPEAR TO SCATTER OUT AND DROP
SOUTH FOR FRIDAY. THEREFORE...BOTH THURSDAY AND FRIDAY SHOULD END UP
SUNNY/MOSTLY SUNNY. WINDS ARE FORECAST OUT OF GOOD DIRECTIONS FOR
WARMING...SOUTHWEST ON THURSDAY AND WEST TO NORTHWEST ON FRIDAY...
THOUGH THE SPEEDS ARE 5 TO 10 KT AT BEST. PAST VERIFICATION OF ABOVE
NORMAL TEMPERATURE EVENTS SHOWS THAT THE ECMWF TENDS TO DO THE
BEST...SO THIS FORECAST LEANS CLOSE TO THE ECMWF GUIDANCE...
PARTICULARLY FOR HIGHS.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
237 PM CST TUE JAN 3 2012
03.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN VERY GOOD
AGREEMENT WITH THE HANDLING OF THE UPPER AIR AND SURFACE PATTERNS
THROUGHOUT MUCH OF THE CONUS DURING THE LONG TERM PERIOD. THIS LEADS
TO...AT LEAST AT THE MOMENT...ABOVE AVERAGE CONFIDENCE. GENERAL
PATTERN SHOWS TROUGHING OVER THE FORECAST AREA SOUTHWESTWARD INTO
THE SOUTHWEST U.S. FOR THE WEEKEND. THIS TROUGHING IS CREATED BY THE
TROUGH APPROACHING THE AREA ON FRIDAY...A POTENT SHORTWAVE DROPPING
SOUTH THROUGH THE ROCKIES...AND THEN ON SUNDAY A SHORTWAVE DROPPING
DOWN TOWARD THE AREA. THIS LAST SHORTWAVE COMES DOWN A BUILDING
RIDGE OVER THE WESTERN U.S. INTO SOUTHWEST CANADA. WITH THE UPPER
TROUGHING OVER THE FORECAST AREA FRIDAY NIGHT THROUGH SUNDAY...
COOLER TEMPERATURES CAN BE EXPECTED. 850MB TEMPS FALL TO -6 TO -10C
AT 18Z SATURDAY WITH ONLY A SLIGHT WARM UP TO -5 TO -8C AT 18Z
SUNDAY. A BLEND OF GUIDANCE SEEMS REASONABLE FOR TEMPERATURES AT
THIS TIME. DESPITE THE UPPER TROUGHING MOVING ACROSS...THERE IS VERY
LITTLE MOISTURE TO WORK WITH...THEREFORE NO PRECIPITATION IS
FORECAST FOR THE WEEKEND AT THIS TIME.
FOR MONDAY INTO TUESDAY...A MORE POTENT UPPER TROUGH LOOKS TO MOVE
OUT OF THE NORTHEAST PACIFIC INTO SOUTHWEST CANADA...WHICH MAY START
DIGGING INTO THE NORTHERN PLAINS LATE TUESDAY. THIS UPPER TROUGH
HELPS SHUNT THE BUILDING RIDGING OUT WEST TOWARDS THE FORECAST
AREA...BRINGING WITH IT YET ANOTHER SURGE OF PACIFIC AIR. 850MB
TEMPS CLIMB RAPIDLY TO AT LEAST 0 TO +6C BY 00Z TUESDAY...IF NOT
HIGHER. BY 12Z TUESDAY...THEY ARE SOLIDLY UP TO 6-8C. SOME COOLING
COULD OCCUR LATE TUESDAY...DEPENDING ON HOW FAST THAT UPPER TROUGH
APPROACHES. IN ANY EVENT...BOTH MONDAY AND TUESDAY LOOK ABOVE TO
WELL ABOVE NORMAL AGAIN...ESPECIALLY GIVEN THE LACK OF SNOW COVER.
STAYED CLOSER TO THE WARM END OF GUIDANCE FOR HIGHS. PRECIPITATION
CHANCES STILL ARE NIL WITH A LACK OF MOISTURE...AND FORCING IN THIS
CASE.
LOOKING AHEAD...A COLD SHOT OF AIR...SIMILAR TO THE ONE JUST
EXPERIENCED YESTERDAY...APPEARS IN THE OFFERING FOR THE MIDDLE AND
END OF NEXT WEEK. THIS IS DUE TO THE TROUGHING APPROACHING THE AREA
ON TUESDAY DIGGING DOWN TOWARDS THE OHIO VALLEY. RIGHT NOW ANY
PRECIPITATION ASSOCIATED WITH THE TROUGH APPEARS TO BE LIGHT...BUT
THIS IS STILL 8-10 DAYS OUT.
&&
.AVIATION...THROUGH 18Z WEDNESDAY
1118 AM CST TUE JAN 3 2012
POSITIVE TILT SHORT WAVE TROUGH OVER EASTERN MONTANA WILL CONTINUE
TO MOVE SOUTHEAST AND ACROSS THE UPPER MIDWEST TONIGHT. WHILE THE
SHORT WAVE TROUGH WILL PRODUCE GOOD VERTICAL MOTION AS IT COMES
THROUGH...IT JUST WILL NOT BE STRONG ENOUGH TO PRODUCE ANYTHING
OTHER THAN CLOUDS AS THE ATMOSPHERE IS VERY DRY WITH NO CHANCE FOR
ANY MOISTURE RETURN. JUST EXPECTING A HIGH VFR CEILING TO OCCUR
UNTIL THE WAVE PASSES THROUGH. A TIGHT PRESSURE GRADIENT WILL
REMAIN IN PLACE THROUGH THE REMAINDER OF THE AFTERNOON AHEAD OF
THE FRONT ASSOCIATED WITH THE SHORT WAVE TROUGH. STILL EXPECTING
SOUTH WINDS TO BE SUSTAINED BETWEEN 15 AND 20 KNOTS WITH SOME
GUSTS OF 20 TO 25 KNOTS THROUGH SUNSET. THE GRADIENT WILL START
TO RELAX THIS EVENING AS THE FRONT APPROACHES WITH A WIND SHIFT TO
THE NORTHWEST OCCURRING OVERNIGHT ONCE THE FRONT GOES THROUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
237 PM CST TUE JAN 3 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1212 PM CST TUE JAN 3 2012
.UPDATE...CIRRUS BLOWING ACROSS WISCONSIN IN UPPER LEVEL
NORTHWEST FLOW. RUC PROGS SHOW APPROACHING POCKETS OF DIVERGENCE
AND HIGHER RH IN 500-300MB LAYER...SUGGESTING THE CIRRUS OVER
EASTERN MN/WESTERN WI WILL CONTINUE TO MOVE OUR WAY. THUS...KEPT
THE PREVIOUS CLOUD TREND. MORNING TEMP TREND WAS TOO SLOW TO WARM
OVER THE BARE GROUND OF THE SOUTHWEST CWA...SO ADJUSTED THE TREND
INTO THE EARLY AFTERNOON.
&&
.AVIATION/18Z TAFS/...MID AND HIGH LEVEL CLOUDS EXPECTED THROUGH
TONIGHT AS SHORTWAVE ROLLS THROUGH...WITH BRIEF CLEARING BY
MORNING. MOISTURE VERY LACKING IN THE LOWER LEVELS...SO NOT
EXPECTING ANY PRECIP WITH THE WAVE. ANOTHER QUIET DAY EXPECTED
WEDNESDAY...WITH ONLY MORE MID AND HIGH LEVEL CLOUDS MOVING IN
LATE MORNING OR EARLY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 309 AM CST TUE JAN 3 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE HIGH.
LARGE MID/UPPER LEVEL TROUGH OVER THE EASTERN U.S. WITH A
MID/UPPER LEVEL RIDGE EXTENDING INTO WISCONSIN THIS AFTERNOON.
A SHORTWAVE IS THEN EXPECTED TO PUSH ACROSS MONTANA AND DROP
SOUTHEAST ACROSS THE CENTRAL PLAINS...THAT EXTENDS INTO SOUTHEAST
WISCONSIN LATE TONIGHT.
THE SURFACE HIGH PRESSURE RIDGE WILL BE OVERHEAD THIS
MORNING...BEFORE PUSHING EAST WITH A SOUTH FLOW AND WARM
ADVECTION PATTERN BY NOON...AHEAD OF A TROUGH OVER THE PLAINS.
MAIN FORECAST CONCERN IS WITH MID LEVEL CLOUDS ASSOCIATED WITH
THE WARM AIR ADVECTION AND WEAK UPWARD MOTION. LOW LEVELS ARE DRY
SO NO PRECIPITATION EXPECTED.
MID LEVEL CLOUDS ARE AGAIN EXPECTED TONIGHT WITH THE APPROACHING
SHORTWAVE. LIFT IS PRESENT...ESPECIALLY IN THE MID LAYERS...BUT
DRY AIR BETWEEN 5 AND 12 THSD FT SHOULD PREVENT ANY PRECIPITATION.
NAM FORECAST SOUNDINGS SHOW MUCH OF THE WARM AIR TO BE AROUND 6 TO
7 THSD FT...WITH A RATHER DEEP LOW LEVEL INVERSION. SOME INCREASE
IN MOISTURE AROUND 4 THSD FT...BUT FORECAST SOUNDINGS DO NOT QUITE
REACH SATURATION.
SHORT TERM...WEDNESDAY THROUGH THURSDAY NIGHT...FORECAST
CONFIDENCE MEDIUM TO HIGH.
COLD FRONT MOVES EAST OF THE REGION WEDNESDAY...WITH SHORT TERM
MODELS BRINGING A VORTICITY MAXIMUM SOUTHEAST THROUGH NORTHERN
WISCONSIN IN ITS WAKE. AREA FORECAST SOUNDINGS ONLY SHOW SOME MID
LEVEL CLOUDS MOVING THROUGH THE REGION. HIGHS SHOULD STILL REACH
THE MID 30S...ABOVE SEASONAL NORMALS.
WARM AIR ADVECTION THEN TAKES HOLD OF THE REGION WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT...AS NORTHWEST FLOW ALOFT LINGERS.
1000/500MB THICKNESSES RISE FROM AROUND 540 DM AT 00Z
THURSDAY...TO NEAR 550 DM BY 12Z FRIDAY. THE 00Z NAM RUN IS EVEN
MORE AGGRESSIVE...WITH LOWER TO MID 550S DM THICKNESSES. SOUTH TO
SOUTHWEST WINDS SHOULD ALLOW HIGH TEMPERATURES TO RISE INTO THE
UPPER 30S TO LOWER 40S THURSDAY...WITH LOWS IN THE UPPER 20S TO
LOWER 30S THURSDAY NIGHT.
LONG TERM...FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM.
COLD FRONT PUSHES EAST THROUGH THE AREA ON FRIDAY PER ECMWF AND
GFS...WITH A DECENT VORTICITY MAXIMUM PUSHING THROUGH THE AREA
FRIDAY NIGHT. AREA FORECAST SOUNDINGS FROM THE GFS ARE FAIRLY DRY
DURING THIS PERIOD...SO THE DRY FORECAST WILL CONTINUE. COLD AIR
ADVECTION LATER FRIDAY AND FRIDAY NIGHT WILL BRING COOLER BUT
STILL ABOVE NORMAL TEMPERATURES.
SECONDARY VORTICITY MAXIMUM SHIFTS SOUTHEAST THROUGH THE AREA
SATURDAY...THEN SHITS EAST SATURDAY NIGHT. DRY AIRMASS PER GFS
FORECAST SOUNDINGS LEADS TO CONTINUATION OF DRY FORECAST.
TEMPERATURES REMAIN MILD.
GFS/ECMWF BRING A SHORTWAVE TROUGH THROUGH THE REGION SUNDAY
NIGHT...THEN SOUTHEAST ON MONDAY. DRY CONDITIONS ARE EXPECTED TO
CONTINUE DURING THIS TIME. MILD TEMPERATURES SHOULD CONTINUE AS
WARM AIR ADVECTION RETURNS BY MONDAY.
AVIATION/12Z TAFS/...
VFR CONDITIONS EXPECTED. AS SURFACE HIGH EXITS SOUTHEAST WISCONSIN
BY AFTERNOON...WARM AIR ADVECTION ON SOUTH WINDS AHEAD OF AN
APPROACHING TROUGH WILL GENERATE LIFT BUT MAINLY MID/UPPER LEVEL
CLOUDS. THE TROUGH WILL MOVE ACROSS SOUTHERN WISCONSIN LATE
TONIGHT...BUT ANY PRECIPITATION SHOULD FALL TO THE NORTH OF THE
FORECAST AREA.
MARINE...
WINDS WILL CONTINUE TO DIMINISH AS A RIDGE OF HIGH PRESSURE MOVES
ACROSS LAKE MICHIGAN BY NOON. SOUTH WINDS WILL INCREASE LATER THIS
AFTERNOON...BUT SHOULD REMAIN BELOW SMALL CRAFT CRITERIA. THE
TROUGH IS EXPECTED TO REACH LAKE MICHIGAN LATE TONIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WIMBERLEY/DDV
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
WEDNESDAY THROUGH MONDAY...WOOD