Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 03/08/12
AREA FORECAST DISCUSSION...UPDATED
NWS TALLAHASSEE FL
615 AM EST Tue Mar 6 2012
.UPDATE...Aviation section.
&&
.SYNOPSIS...
08Z water vapor and H4 RUC analysis shows northern stream flow
carving out a significant trough over the Pacific Northwest coast
this morning. This flow then develops downstream ridging over the
high plains/Great Lakes before digging yet another trough over the
Northeastern States. Further south, flow is more zonal along the
northern Gulf coast. WV imagery shows the mid/upper levels overhead
are quite dry this morning, and this is confirmed by the 00Z KTLH
sounding which shows a dry profile throughout the troposphere and a
resulting PW of only around 0.3". The dry column and lack of any
synoptic forcing is resulting in clear skies region-wide this early
this morning.
At the surface, 1035mb high pressure centered over VA/NC extends
southwest to control the northern Gulf coast. The ridge center to
our north is providing the area with a steady NE breeze this
morning. This breeze is keeping the boundary layer mixed, and as a
result, our temps are not falling as expected in many locations. It
now appears that widespread 30s will be difficult to achieve and
will adjust temperatures up the next few hours to better blend with
the post-sunrise forecast.
&&
.SHORT TERM (Today through Thursday)...
Today and Tonight,
Dry and seasonable weather expected across the region. Zonal mid and
upper level flow prevails along the northern Gulf coast while at the
surface a strong ridge of high pressure slides off the eastern
seaboard. Skies will be clear this morning, and then give way to a
few fair weather cu during the afternoon, as easterly flow begins to
deliver increasing low level Atlantic moisture. Decent diurnal
mixing up to around 850mb where temps are 6-7C will allow temps to
top out in the upper 60s to lower 70s this afternoon. A tight
gradient in place will prevent boundary layer de-coupling tonight
and should once again prevent temps from rapidly dropping. Went with
a MAV/MET blend for low temps which yields mid/upper 40s inland and
generally 50s along the immediate coast.
Wednesday/Wednesday Night,
Potent trough/upper low will drift eastward over the inter-mountain
west and toward the central/southern Plains. In response to these
height falls, amplified ridging/heights rises will be experienced
over the Gulf and SE states. This mid/upper level ridging will keep
our forecast dry and increasingly warm. Skies will generally remain
partly cloudy due to the influx of low level Atlantic moisture with
high temps creeping up into the low/mid 70s. Along the immediate
coast (especially Franklin/Gulf counties) temps will likely hold in
the 60s with the flow off the cooler shelf waters. Low temps Wed
Night in the 50s.
Thursday,
Upper level trough and associated surface front will reach the
mid/lower MS valley with a round of shower and storms. However, for
our region, the protective upper ridge will remain in control and
keep rain chances out the forecast. Temperatures will also continue
to rise with highs approaching 80 for many inland locations. Similar
to Wednesday, a southeast flow off the shelf waters will keep the
immediate coast cooler.
&&
.LONG TERM (Friday through next Tuesday)...
Overall confidence in this part of the forecast will remain below
normal as we continue to see large differences in the solutions
presented by various models. Once thing that is certain is that the
00Z operational GFS run appears to be an outlier in its handling of
the energy that cuts off over the Desert SW on Thursday. The 05/12Z
Euro appears to have support from the latest NAM and also quite a
few of the GFS ensemble members in holding that energy in place for
a longer period of time than the latest GFS shows. We will try to
work the Euro solution into the forecast as much as possible and
take a look at the new 00Z Euro before putting on the finishing
touches. Overall, we favor a slower evolution in the pattern than
indicated by the GFS. We will however see the surface ridge continue
to slide slowly south and that will veer our low level winds and
bring in increasing moisture toward the end of the week. We will
stick with the recent forecasts of returning PoPs to the forecast on
Friday and keeping in at least some PoP through the weekend and on
into early next week. Temperature will be above normal through the
period with lows generally in the 50s to around 60 and highs in the
mid to upper 70s. A few spots could reach 80 on Friday, Saturday and
Sunday, especially across inland portions of the FL Big Bend.
&&
.AVIATION (THROUGH 12Z WEDNESDAY).
VFR conditions are forecast prevail across the area through the TAF
period with clear skies holding into the afternoon. East winds will
be sustained around 12 knots at times from mid morning on through
the afternoon with a few higher gusts possible. Scattered stratocu
will move in from the east during the mid to late afternoon hours
and persist through the evening. There is a small chance that MVFR
ceilings will work into the VLD area late tonight, but confidence
was too low to place in the forecast at this time.
&&
.MARINE...
A strong area of high pressure will move east to the Carolina coast
later today and then off the eastern seaboard Wednesday. Associated
with this area of high pressure, a tight gradient will remain in
place through the middle of the week. Easterly flow is expected to
reach advisory levels at times this morning, and then again tonight
into Wednesday morning. Moderate east to southeast flow will
continue through Thursday ahead of an approaching frontal system.
&&
.FIRE WEATHER...
Red flag conditions are once again forecast for today across most of
our FL zones due to a combination of RH below 35 percent and
dispersion indices above 75. The RH forecast has come up across the
eastern FL Big Bend zones, but it is very close to 35 percent and
dispersion indices are higher there. Feel more comfortable leaving
the warning in place for these borderline conditions considering the
dispersion numbers. An increase in RH will preclude red flag
conditions from being reached for the remainder of the week after
today and then on through the weekend.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 71 48 75 51 79 / 0 0 0 0 10
Panama City 69 53 71 57 74 / 0 0 0 0 10
Dothan 69 49 73 53 78 / 0 0 0 0 10
Albany 68 47 72 52 78 / 0 0 10 0 10
Valdosta 68 48 73 52 80 / 0 0 10 0 10
Cross City 73 49 77 53 81 / 0 0 0 0 10
Apalachicola 66 53 68 58 71 / 0 0 0 0 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...Red Flag Warning from Noon EST /11 AM CST/ today to 6 PM EST /5
PM CST/ this evening for Calhoun-Central Walton-Coastal Bay-
Coastal Dixie-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 until 10 AM EST Wednesday for Coastal
waters From Ochlockonee River to Apalachicola FL out to 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
Long Term/Aviation/Fire Wx...Wool
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
335 AM EST Tue Mar 6 2012
.SYNOPSIS...
08Z water vapor and H4 RUC analysis shows northern stream flow
carving out a significant trough over the Pacific Northwest coast
this morning. This flow then develops downstream ridging over the
high plains/Great Lakes before digging yet another trough over the
Northeastern States. Further south, flow is more zonal along the
northern Gulf coast. WV imagery shows the mid/upper levels overhead
are quite dry this morning, and this is confirmed by the 00Z KTLH
sounding which shows a dry profile throughout the troposphere and a
resulting PW of only around 0.3". The dry column and lack of any
synoptic forcing is resulting in clear skies region-wide this early
this morning.
At the surface, 1035mb high pressure centered over VA/NC extends
southwest to control the northern Gulf coast. The ridge center to
our north is providing the area with a steady NE breeze this
morning. This breeze is keeping the boundary layer mixed, and as a
result, our temps are not falling as expected in many locations. It
now appears that widespread 30s will be difficult to achieve and
will adjust temperatures up the next few hours to better blend with
the post-sunrise forecast.
&&
.SHORT TERM (Today through Thursday)...
Today and Tonight,
Dry and seasonable weather expected across the region. Zonal mid and
upper level flow prevails along the northern Gulf coast while at the
surface a strong ridge of high pressure slides off the eastern
seaboard. Skies will be clear this morning, and then give way to a
few fair weather cu during the afternoon, as easterly flow begins to
deliver increasing low level Atlantic moisture. Decent diurnal
mixing up to around 850mb where temps are 6-7C will allow temps to
top out in the upper 60s to lower 70s this afternoon. A tight
gradient in place will prevent boundary layer de-coupling tonight
and should once again prevent temps from rapidly dropping. Went with
a MAV/MET blend for low temps which yields mid/upper 40s inland and
generally 50s along the immediate coast.
Wednesday/Wednesday Night,
Potent trough/upper low will drift eastward over the inter-mountain
west and toward the central/southern Plains. In response to these
height falls, amplified ridging/heights rises will be experienced
over the Gulf and SE states. This mid/upper level ridging will keep
our forecast dry and increasingly warm. Skies will generally remain
partly cloudy due to the influx of low level Atlantic moisture with
high temps creeping up into the low/mid 70s. Along the immediate
coast (especially Franklin/Gulf counties) temps will likely hold in
the 60s with the flow off the cooler shelf waters. Low temps Wed
Night in the 50s.
Thursday,
Upper level trough and associated surface front will reach the
mid/lower MS valley with a round of shower and storms. However, for
our region, the protective upper ridge will remain in control and
keep rain chances out the forecast. Temperatures will also continue
to rise with highs approaching 80 for many inland locations. Similar
to Wednesday, a southeast flow off the shelf waters will keep the
immediate coast cooler.
&&
.LONG TERM (Friday through next Tuesday)...
Overall confidence in this part of the forecast will remain below
normal as we continue to see large differences in the solutions
presented by various models. Once thing that is certain is that the
00Z operational GFS run appears to be an outlier in its handling of
the energy that cuts off over the Desert SW on Thursday. The 05/12Z
Euro appears to have support from the latest NAM and also quite a
few of the GFS ensemble members in holding that energy in place for
a longer period of time than the latest GFS shows. We will try to
work the Euro solution into the forecast as much as possible and
take a look at the new 00Z Euro before putting on the finishing
touches. Overall, we favor a slower evolution in the pattern than
indicated by the GFS. We will however see the surface ridge continue
to slide slowly south and that will veer our low level winds and
bring in increasing moisture toward the end of the week. We will
stick with the recent forecasts of returning PoPs to the forecast on
Friday and keeping in at least some PoP through the weekend and on
into early next week. Temperature will be above normal through the
period with lows generally in the 50s to around 60 and highs in the
mid to upper 70s. A few spots could reach 80 on Friday, Saturday and
Sunday, especially across inland portions of the FL Big Bend.
&&
.AVIATION (THROUGH 06Z WEDNESDAY).
VFR conditions will prevail across the forecast area through the TAF
period with clear skies holding into the afternoon. East winds will
be sustained around 12 knots at times from mid morning on through
the afternoon with a few higher gusts possible. Scattered SC will
move in from the east during the mid to late afternoon hours and
persist through the evening.
&&
.MARINE...
A strong area of high pressure will move east to the Carolina coast
later today and then off the eastern seaboard Wednesday. Associated
with this area of high pressure, a tight gradient will remain in
place through the middle of the week. Easterly flow is expected to
reach advisory levels at times this morning, and then again tonight
into Wednesday morning. Moderate east to southeast flow will
continue through Thursday ahead of an approaching frontal system.
&&
.FIRE WEATHER...
Red flag conditions are once again forecast for today across most of
our FL zones due to a combination of RH below 35 percent and
dispersion indices above 75. The RH forecast has come up across the
eastern FL Big Bend zones, but it is very close to 35 percent and
dispersion indices are higher there. Feel more comfortable leaving
the warning in place for these borderline conditions considering the
dispersion numbers. An increase in RH will preclude red flag
conditions from being reached for the remainder of the week after
today and then on through the weekend.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 71 48 75 51 79 / 0 0 0 0 10
Panama City 69 53 71 57 74 / 0 0 0 0 10
Dothan 69 49 73 53 78 / 0 0 0 0 10
Albany 68 47 72 52 78 / 0 0 10 0 10
Valdosta 68 48 73 52 80 / 0 0 10 0 10
Cross City 73 49 77 53 81 / 0 0 0 0 10
Apalachicola 66 53 68 58 71 / 0 0 0 0 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...Red Flag Warning from Noon EST /11 AM CST/ today to 6 PM EST /5
PM CST/ this evening for Calhoun-Central Walton-Coastal Bay-
Coastal Dixie-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 until 10 AM EST Wednesday for Coastal
waters From Ochlockonee River to Apalachicola FL out to 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
Long Term/Aviation/Fire Wx...Wool
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
533 PM CST WED MAR 7 2012
.AVIATION...
A STRONG COLD FRONT MOVING THROUGH THE REGION NOW WILL BE EAST OF
ALL TAF SITES BY 03Z. A NARROW BAND OF SHRA WILL ACCOMPANY THE
FRONT. A CB WAS IN INCLUDED EARLY THIS EVENING AT KDBQ/KMLI/KBRL
TO COVER A LOW PROBABILITY OF ISOLATED TSRA. SCATTERED SHRA WITH
MAINLY MVFR CIGS WILL TRAIL THE FRONT. AN AREA OF IFR CIGS OVER
NORTH CENTRAL IA MAY BRUSH KDBQ LATE THIS EVENING. THE SHRA
SHOULD BE EAST OF THE TAF SITES BY 09Z. IF THE SHRA REMAIN LONGER
THAN EXPECTED THERE COULD BE A MIX OF LIGHT RN/SN JUST AS THE
PRECIPITATION IS ENDING. CIGS TO IMPROVE TO VFR LATE TONIGHT
WITH VFR CONDITIONS CONTINUING FOR THE REMAINDER OF THE FORECAST
PERIOD. GUSTY NORTHWEST WINDS WILL DEVELOP BEHIND THE FRONT AND
CONTINUE INTO THURSDAY AFTERNOON. ..DLF..
&&
.PREV DISCUSSION... /ISSUED 315 PM CST WED MAR 7 2012/
SYNOPSIS...
12Z UA ANALYSIS HAS A STRONG LLJ RUNNING FROM THE GULF COAST INTO
THE NORTHEAST. A STRONG CANADIAN COLD FRONT RAN FROM THE ARROWHEAD
OF MINNESOTA INTO SOUTHEAST COLORADO. A VERY PRONOUNCED MOISTURE
PLUME WAS OVER THE MID CONUS WITH 850MB DEW POINTS GETTING INTO THE
LOW TEENS IN SOUTH TEXAS. SATELLITE/RADAR TRENDS THROUGH MID
AFTERNOON SHOW A LARGE EXPANSE OF MID CLOUDS WITH LOW CLOUDS ALONG
AND BEHIND THE COLD FRONT. RADARS SHOW PRECIPITATION DEVELOPING
ALONG AND BEHIND THE FRONT FROM IOWA INTO MINNESOTA.
18Z SFC ANALYSIS HAD A WEAK LOW NEAR KRPD IN NORTHWEST WISCONSIN
WITH THE COLD FRONT FROM NEAR THE LOW BACK INTO THE OKLAHOMA
PANHANDLE NEAR KGUY. A SUBTLE PRE-FRONTAL TROF RAN FROM NEAR KRST TO
KFNB. DEW POINTS AHEAD OF THE FRONT WERE IN THE 40S AND 50S THAT
QUICKLY DROP INTO THE 20S AND 30S AND FINALLY TEENS BEHIND THE FRONT.
SHORT TERM...TONIGHT AND THURSDAY...
GFS MOISTURE INITIALIZATION WAS WAY TOO MOIST AGAIN WITH ERRORS OF
3-5C COMMON IN THE LOWEST LAYERS. THE WRF WAS BETTER BUT STILL TOO
MOIST. ALTHOUGH THE RUC WAS SLIGHTLY TOO MOIST...IT WAS DEPICTING
QUITE WELL WHAT WAS HAPPENING AND ITS TRENDS WERE USED HEAVILY FOR
TONIGHT. THE ECMWF/GEM/UKMET WERE FAVORED FOR THURSDAY.
RUC TRENDS COMBINED WITH RECENT RADAR TRENDS INDICATE THAT PRECIP
WILL BE MAINLY ALONG/BEHIND THE FRONT. THE WAA TOOL USING THE RUC AT
THE 925MB SFC AGREES QUITE WELL ON HOW PRECIP HAS DEVELOPED SO FAR.
THUS PRECIP WILL DEVELOP/MOVE INTO THE NORTHWEST CWFA LATE THIS
AFTERNOON/EVENING. SOME PRE-FRONTAL SHOWERS MAY OCCUR LATE THIS
AFTERNOON WITH PEAK HEATING. PER THE LIFT TOOL...THE BEST CHANCES
FOR ANY ISOLATED TSRA WILL BE OVER THE NEXT 4-6 HRS IN THE NORTHWEST
PART OF THE CWFA. THUS WILL INCLUDE A MENTION OF ISOLATED THUNDER
THERE.
ONCE THE COLD FRONT PASSES ANY ONE AREA...TEMPERATURES SHOULD DROP
ABOUT 15 DEGREES IN JUST OVER AN HOUR.
BETWEEN MID EVENING AND MIDNIGHT AREAL COVERAGE OF THE RAIN WILL
EXPAND AS THE FRONT CONTINUES MOVING SOUTHEAST. THE EVENING HOURS
WILL BE THE MOST LIKELY TIME PERIOD FOR THE RELATIVELY HEAVIER RAIN
AMOUNTS BUT EVEN THAT AMOUNT WILL BE UNDER ONE QUARTER INCH.
JUST PRIOR TO MIDNIGHT SOME SNOW MAY MIX IN WITH THE RAIN BEFORE IT
ENDS ACROSS THE FAR NORTHWEST CWFA. AT THE VERY WORST A LOCALIZED
DUSTING MAY OCCUR.
AFTER MIDNIGHT THE RAIN WILL END FROM NORTHWEST TO SOUTHEAST AS
CONDENSATION PRESSURE DEFICITS RISE AND THE BETTER FORCING MOVES
EAST OF THE CWFA. MOST OF THE CWFA SHOULD BE PRECIPITATION FREE BY
SUNRISE. THE INCOMING HIGH PRESSURE MAY ALLOW SKIES TO PARTIALLY
CLEAR. LOW TEMPERATURES WILL OCCUR AT OR SHORTLY AFTER SUNRISE
THURSDAY.
ON THURSDAY...SOME LINGERING SPRINKLES MAY BE SEEN IN THE FAR EAST
AND SOUTHEAST PARTS OF THE CWFA BEFORE ENDING BY MID MORNING. HIGH
PRESSURE BUILDING IN SHOULD ALLOW SKIES TO CLEAR FURTHER BEFORE HIGH
CLOUDS MOVE BACK INTO THE AREA. LOW LEVEL LAPSE RATES ARE REASONABLY
STEEP AND SHOULD PROMOTE GOOD MIXING AND RESULT IN ANOTHER BREEZY IF
NOT WINDY DAY. HIGH TEMPERATURES SHOULD BE 15-20 DEGREES COLDER BUT
STILL ABOVE NORMAL. ..08..
LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY...
ABOVE NORMAL TO WELL ABOVE NORMAL WITH LIGHT RAIN CHANCES SUNDAY INTO
MONDAY.
OVERALL...INITIALIZATION AND VERIFICATION AVERAGE WITH ONCE AGAIN
SIGNIFICANT BL PROBLEMS WITH LOW LEVEL THERMAL (TOO COOL) AND
MOISTURE FIELDS (TOO HIGH). HI-RES ECMWF HANDLING THIS AND ALSO RUN
TO RUN CONTINUITY THE BEST. LIKELY GUIDANCE TEMPERATURES DAYS 3-7
ARE AT LEAST A CATEGORY OR TWO TOO LOW...OR MAY NEED RAISING 3-5
DEGREES FOR HIGHS MOST DAYS.
THURSDAY NIGHT...WINDS MAY DECOUPLE UNDER A FAIR SKY...IF SO THEN
MINS MAY NEED TO BE TRIMMED BY UP TO 3 DEGREES. THIS WOULD RESULT
IN LOWS IN THE LOWER TO MIDDLE 20S.
FRIDAY THROUGH SATURDAY...FAIR SKIES AND WARMING TREND. LIGHT SOUTH
WINDS AND COPIOUS SUNSHINE TO MAKE FOR COMFORTABLE MARCH WEATHER.
HIGHS MAY APPROACH 60S IN SOME SECTIONS ON SATURDAY. MINS SATURDAY
AM WITHIN A FEW DEGREES OF 32F AND SUNDAY AM AROUND 40F.
SUNDAY AND MONDAY...AREAS OF LIGHT TO POSSIBLY MODERATE RAIN...MOSTLY
SUNDAY. HAVE KEPT CHANCE POPS AS TREND HAS BEEN A TRACK A BIT SOUTH
THE PAST 3 DAYS. BEST FORCING SOUTH AND SUGGEST TOTAL RAIN AMOUNTS TO
BE GENERALLY BELOW A QUARTER INCH MOST LOCATIONS. HIGHS SUNDAY TO BE
IMPACTED BY AMOUNT OF CLOUD COVER. SKIES TO CLEAR MONDAY WITH HIGHS
WELL INTO THE 60S. MINS SUNDAY AND MONDAY MORNING IN THE 40S MOST
LOCATIONS.
TUESDAY AND WEDNESDAY...DRY WITH WELL ABOVE NORMAL TEMPERATURES.
HIGHS IN THE 60S WITH LOWS IN THE 40S AND LOWER 50S ON THURSDAY
MORNING. SOME LOW LEVEL THERMAL FIELDS SUGGEST 70S POSSIBLE ON ONE
OR MORE DAYS WITH ENOUGH HEATING FOR LATER SHIFTS TO RECONSIDER.
THESE TEMPERATURES ARE 15-20 DEGREES ABOVE NORMAL. ..NICHOLS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1118 AM CST TUE MAR 6 2012
.AVIATION...
CLEAR SKIES...BUT WINDY SOUTH TO SOUTHWEST WINDS OF 16 TO 25
KTS...GUSTING TO 26 TO 33 KTS...WILL CONTINUE TO BLOW OVER IOWA
AND ILLINOIS THROUGH SUNSET THIS EVENING...FOLLOWED BY LESS
GUSTY...BUT STILL SUSTAINED 15 TO 20 KT WINDS OVERNIGHT. AFTER 14Z
TOMORROW...STRATUS MAY MOVE OVER ALL SITES..AND THIS COULD BE
MVFR...BUT FOR NOW...I WILL ONLY PUT DBQ AT 3000 FT...WITH OTHER
SITES AROUND 3500 FT. WINDS WILL AROUND 14 KTS SOUTHWEST
TOMORROW...GUSTING TO THE 20 TO 25 KT RANGE.
&&
.PREV DISCUSSION... /ISSUED 652 AM CST TUE MAR 6 2012/
UPDATE...
12Z DVN RAOB SHOWS IMPRESSIVE LOW LEVEL INVERSION... WHICH WHEN
MIXED OUT YIELDS TEMPS AROUND 70 DEGS. NO REASON WITH REMAINING
SNOW COVER TO QUICKLY ERODE TO THINK THIS WON/T OCCUR... AND SENT
UPDATE TO NUDGE UP TEMPS ALL AREAS WITH WIDESPREAD 60S WITH L70S
SOUTH. THIS ALSO DEPICTED WELL IN 2M TEMP FCST OF HRRR IN LAST
SEVERAL RUNS. COULD END UP BEING WITHIN A FEW DEGS OF RECORDS AT
SOME SITES MAINLY SOUTH. THE RECORDS FOR TDY ARE AS FOLLOWS...
BRL (72 IN 2005 AND PREVIOUS YRS)... MLI (73 IN 2005) CID (73 IN
2005) AND DBQ (69 IN 2000).
PREV DISCUSSION... /ISSUED 319 AM CST TUE MAR 6 2012/
SYNOPSIS...
LATEST SFC ANALYSIS PLACES MAIN LOW OVER MT WITH SECONDARY LOWS
OVER NW ND AND CENTRAL SD. WARM FRONT EXTENDS SE FROM THE
LOWS THROUGH SW IA AND NORTHEAST MO. GUSTY SE WINDS WITH
INCREASING MSLP GRADIENT COUPLED WITH LOW LEVEL WARM ADVECTION
RESULTING IN NEAR STEADY TEMPS. BUT WARM FRONT ON THE MARCH
NWD WITH KIRKSVILLE MO HAVING GONE FROM 34 TO 48 DEGS BETWEEN
06Z- 08Z. FLOW PATTERN ALOFT HAS TEMPORARILY FLATTENED AND IS
NEARLY ZONAL BUT IN PROCESS OF BECOMING SOUTHWESTERLY AS SHORTWAVE
ENERGY DIVES TOWARD GREAT BASIN.
SHORT TERM...TODAY AND TONIGHT...
MAIN CONCERNS ARE WITH WINDS AND TEMPS. SFC COLD FRONT TO EMERGE
INTO THE PLAINS TDY AND MODELS IN GOOD AGREEMENT ON LAYING OUT
THE FRONT FROM NEAR THE ARROWHEAD OF MN THROUGH NW IA BY 12Z WED.
THUS CWA WILL RESIDE IN THE PRE-FRONTAL WARM SECTOR ENVIRONMENT
THROUGHOUT THE PERIOD CHARACTERIZED BY DRY AND UNSEASONABLY WARM
CONDITIONS WITH E/SE WINDS SHIFTING TO SOUTH AND BECOMING QUITE
BREEZY TO WINDY AT TIMES WITH STRENGTHENING PRESSURE GRADIENT. THE
INITIAL CHALLENGE IS WHETHER HEADLINES FOR WIND NECESSARY. THERE
ARE SOME BIG DIFFERENCES IN MIXING HEIGHTS BETWEEN NAM AND GFS
WITH BIG IMPLICATIONS TO TEMPS AND WINDS. THE DIFFERENCES MOST
LIKELY DUE TO MODELED SNOW COVER WITH 00Z NAM MODELING
WIDESPREAD 1.5 TO 2 INCHES BASICALLY NORTH OF HWY 34. CLOSE
LOOK AT LATE DAY SATL IMAGE FROM YSTDY SHOWED MAIN BATCH OF SNOW
COVER OF 1-2 INCHES IN AREA BOUNDED BY KAWG-KDBQ-KVTI. TEMPS HAVE
BEEN JUST ABOVE FREEZING THIS REGION MOST OF NIGHT THUS SOME
CONTINUED MELT. BOTTOM LINE... DISCARDING NAM SOLUTION AND SIDING
WITH DEEPER MIXED GFS. GFS BUFR SOUNDINGS AND MSLP GRADIENT
SUPPORT WINDS GENERALLY 20-30 MPH WITH SOME HIGHER GUSTS. COULD
SEE A COUPLE SITES REACH LOW END ADVISORY CRITERIA MAINLY ON
SUSTAINED WINDS AOA 30 MPH... WHICH WAS OBSERVED YSTDY IN THE
PLAINS... BUT DOESN/T LOOK WIDESPREAD ENOUGH AND MARGINAL ATTIM TO
PRECLUDE ANY HEADLINES FOR WIND. GUSTY WINDS AND LOW RH VALUES
MAY INCREASE FIRE DANGER FOR DRY GRASS FUELS ELEVATED ABOVE THE
MELTING SNOW AND CONTINUE MENTION IN HWO AND GRAPHICAL WX STORY.
AS FOR HIGHS... GOING FCST LOOKS GOOD BASED OFF GFS BUFR SOUNDINGS
AND PROGGED LOW LEVEL THICKNESS AND VERIFICATION FROM YSTDY IN THE
PLAINS. EXPECT WIDESPREAD 60S... WITH COUPLE SITES POSSIBLY
NEAR 70 DEGS FAR SOUTH AND FEW 50S FAR N/NE. TNGT... UNSEASONABLY
MILD WITH SOUTH WINDS 15 TO 25 MPH AND INCREASE IN CLOUDS
SUPPORTING GOING ABOVE GUIDANCE ON MINS. SOME SUGGESTIONS OF MORE
WIDESPREAD 50S AND POSSIBLY NEEDING TO RAISE COUPLE MORE DEGS BUT
CONTINUE WITH GENERALLY U40S TO L50S. ..05..
LONG TERM...WEDNESDAY THROUGH NEXT MONDAY...
PRIMARY FOCUS IS ON RAIN AND THUNDERSTORM CHANCES WED...AND
ESPECIALLY WED NIGHT WITH THE COLD FRONTAL PASSAGE. STILL A LARGE
DEGREE OF UNCERTAINTY WITH THE NEXT POTENTIAL SYSTEM LATE IN THE
WEEKEND.
WEDNESDAY CERTAINLY LOOKS TO BE ANOTHER WINDY AND WARM DAY. THE
AMOUNT OF LOW LEVEL MOISTURE RETURN IS LIKELY OVERDONE IN THE
MODELS...BASED ON RECENT MODEL PERFORMANCE AND REAL TIME
VERIFICATION. THUS...SIMILAR TO THE THOUGHTS IN THE PREVIOUS
FORECAST...THE POTENTIAL FOR SHOWERS WILL BE LIMITED IN THE
EAST...BUT MORE LIKELY IN THE WEST IN THE AFTERNOON AS ISENTROPIC
LIFT DEVELOPS AND CONDENSATION PRESSURE DEFICITS LOWER. EVEN WITHOUT
WIDESPREAD LOW CLOUDS...INCREASING HIGH LEVEL MOISTURE SHOULD RESULT
IN MOSTLY CLOUDY SKIES AND LIMITED INSOLATION. THE PREFRONTAL
AIRMASS WILL EASILY SUPPORT TEMPERATURES IN THE UPPER 50S TO UPPER
60S...WHICH COULD POTENTIALLY BE EVEN WARMER IF CLOUD COVER IS THIN.
ALL OPERATIONAL MODELS...EXCEPT THE OUTLIER FASTER ECMWF...KEEP THE
COLD FRONT NORTHWEST OF THE FORECAST AREA DURING THE DAYTIME. SOUTH
TO SOUTHWEST WINDS SHOULD BE AT LEAST IN THE RANGE OF 20 TO 30 MPH
RANGE IN THE EAST...AND 15 TO 25 MPH RANGE IN THE WEST CLOSER TO THE
APPROACHING FRONT. MODELS CONTINUE TO PORTRAY A WARM AND DRY LAYER
AROUND 700 MB ABOVE THE MOISTENING LOW LEVELS...THAT SHOULD LIMIT
THE DEPTH OF ANY CONVECTION THAT DEVELOPS AS LOW LEVEL LAPSE RATES
STEEPEN. HAVE THUS LIMITED THE POTENTIAL FOR ISOLATED THUNDERSTORMS
TO THE WEST IN THE LATE AFTERNOON...WHERE 700 MB TEMPERATURES BEGIN
TO COOL.
WEDNESDAY NIGHT...WILL CONTINUE CATEGORICAL POPS FOR RAIN AS THE
COLD FRONT DRIVES SOUTHEAST THROUGH THE FORECAST AREA. GULF MOISTURE
CONVERGING ON THIS BOUNDARY IS SHOWN DRIVING PW VALUES TO AROUND 1
INCH BY 06Z OVER THE FORECAST AREA...AND HIGHER TRENDING ECMWF AND
GEM MODEL QPF LOOKS REASONABLE WITH WIDESPREAD HALF INCH EVENT
TOTALS. THERE WILL BE A PERIOD OF NEGATIVE THETAE LAPSE RATES OVER
ESPECIALLY THE SOUTH IN THE EVENING AND HAVE KEPT ISOLATED
THUNDERSTORM WORDING. FORECAST SOUNDINGS CONTINUE TO INDICATE A
POTENTIAL FOR A BRIEF PERIOD OF MIXED PRECIPITATION OR PERHAPS LIGHT
SNOW ALONG THE BACK EDGE OF THE SYSTEM AS IT WINDS DOWN IN THE NW
LATE. HAVE CONTINUED THIS TREND IN THE FORECAST BUT DO NOT
ANTICIPATE ANY ACCUMULATIONS. MODELS ARE IN DECENT AGREEMENT WITH
THE SURFACE COLD FRONT EXITING THE SOUTHEAST BY SUNRISE...WITH
SUNRISE MINS RANGING FROM THE UPPER 20S NORTHWEST TO THE LOWER 40S
SOUTHEAST.
SOME POST FRONTAL LIGHT RAIN MAY BE LINGERING IN THE SOUTH THU
MORNING. OTHERWISE...HIGH PRESSURE BUILDING INTO THE AREA SHOULD
PROVIDE MOSTLY CLEAR SKIES AND DAYTIME TEMPERATURES RETURNING CLOSER
TO MARCH NORMALS IN THE 40S BOTH THU AND FRI.
A DEVELOPING LOW LEVEL RETURN FLOW SHOULD MODERATE TEMPERATURES BACK
INTO THE 50S SATURDAY THROUGH MONDAY. OVERALL...MODELS CONTINUE TO
ADVERTISE A DEVELOPING UPPER LOW OVER THE SW U.S. LIFTING NORTHEAST
TO BRING PRECIPITATION TO THE LOCAL AREA SUNDAY INTO SUNDAY NIGHT.
THE GFS CONTINUES TO EXHIBIT THE POOREST RUN TO RUN CONTINUITY...AND
ALSO TRENDS FASTER AND MORE SOUTHEASTERLY WITH THE TRACK OF THIS
FEATURE. WHILE CONFIDENCE IN ANY GIVEN SOLUTION IS LOW...TRENDS AND
CONSENSUS SUPPORT CHANCE POPS FOR RAIN SUNDAY INTO SUNDAY
NIGHT...THEN SLIGHT TO LOW END CHANCES INTO MONDAY. ..SHEETS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
..ERVIN..
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
652 AM CST TUE MAR 6 2012
.UPDATE...
12Z DVN RAOB SHOWS IMPRESSIVE LOW LEVEL INVERSION... WHICH WHEN
MIXED OUT YIELDS TEMPS AROUND 70 DEGS. NO REASON WITH REMAINING
SNOW COVER TO QUICKLY ERODE TO THINK THIS WON/T OCCUR... AND SENT
UPDATE TO NUDGE UP TEMPS ALL AREAS WITH WIDESPREAD 60S WITH L70S
SOUTH. THIS ALSO DEPICTED WELL IN 2M TEMP FCST OF HRRR IN LAST
SEVERAL RUNS. COULD END UP BEING WITHIN A FEW DEGS OF RECORDS AT
SOME SITES MAINLY SOUTH. THE RECORDS FOR TDY ARE AS FOLLOWS...
BRL (72 IN 2005 AND PREVIOUS YRS)... MLI (73 IN 2005) CID (73 IN
2005) AND DBQ (69 IN 2000).
&&
.PREV DISCUSSION... /ISSUED 548 AM CST TUE MAR 6 2012/
AVIATION...
MAINLY VFR CONDITIONS EXPECTED THROUGH TONIGHT. TIGHTENING MSLP
GRADIENT BETWEEN LOW PRESSURE EMERGING INTO THE PLAINS AND
DEPARTING HIGH WILL RESULT IN WINDY CONDITIONS WITH SOUTH WINDS
20-30 KTS AND GUSTY BY LATE AM THROUGH AFTN. STRONG INVERSION
EARLY THIS AM WILL LEAD TO LLWS POTENTIAL UNTIL MID AM WITH 12Z
KDVN RAOB SHOWING 54 KTS FROM 210 DEGS AT 2000 FT AGL. WINDS TO
REMAIN GUSTY FROM SOUTH AT 10-20 KTS TNGT. MAY SEE SOME STRATUS
DEVELOP AND/OR MOVE INTO EASTERN IA LATE TNGT AS LOW LEVEL
MOISTURE AXIS BEGINS TO MAKE INROADS AHEAD OF APPROACHING COLD
FRONT. KEPT CIGS IN VFR CAT THOUGH CAN/T RULE OUT SOME MVFR CIGS
BUT CONFIDENCE ON LOWER CIGS IS LOW GIVEN THAT MODELS VERIFYING
TOO MOIST AND OVERDONE WITH NWD EXTENT OF BETTER LOW LEVEL MOISTURE
EARLY THIS AM.
PREV DISCUSSION... /ISSUED 319 AM CST TUE MAR 6 2012/
SYNOPSIS...
LATEST SFC ANALYSIS PLACES MAIN LOW OVER MT WITH SECONDARY LOWS
OVER NW ND AND CENTRAL SD. WARM FRONT EXTENDS SE FROM THE
LOWS THROUGH SW IA AND NORTHEAST MO. GUSTY SE WINDS WITH
INCREASING MSLP GRADIENT COUPLED WITH LOW LEVEL WARM ADVECTION
RESULTING IN NEAR STEADY TEMPS. BUT WARM FRONT ON THE MARCH
NWD WITH KIRKSVILLE MO HAVING GONE FROM 34 TO 48 DEGS BETWEEN
06Z- 08Z. FLOW PATTERN ALOFT HAS TEMPORARILY FLATTENED AND IS
NEARLY ZONAL BUT IN PROCESS OF BECOMING SOUTHWESTERLY AS SHORTWAVE
ENERGY DIVES TOWARD GREAT BASIN.
SHORT TERM...TODAY AND TONIGHT...
MAIN CONCERNS ARE WITH WINDS AND TEMPS. SFC COLD FRONT TO EMERGE
INTO THE PLAINS TDY AND MODELS IN GOOD AGREEMENT ON LAYING OUT
THE FRONT FROM NEAR THE ARROWHEAD OF MN THROUGH NW IA BY 12Z WED.
THUS CWA WILL RESIDE IN THE PRE-FRONTAL WARM SECTOR ENVIRONMENT
THROUGHOUT THE PERIOD CHARACTERIZED BY DRY AND UNSEASONABLY WARM
CONDITIONS WITH E/SE WINDS SHIFTING TO SOUTH AND BECOMING QUITE
BREEZY TO WINDY AT TIMES WITH STRENGTHENING PRESSURE GRADIENT. THE
INITIAL CHALLENGE IS WHETHER HEADLINES FOR WIND NECESSARY. THERE
ARE SOME BIG DIFFERENCES IN MIXING HEIGHTS BETWEEN NAM AND GFS
WITH BIG IMPLICATIONS TO TEMPS AND WINDS. THE DIFFERENCES MOST
LIKELY DUE TO MODELED SNOW COVER WITH 00Z NAM MODELING
WIDESPREAD 1.5 TO 2 INCHES BASICALLY NORTH OF HWY 34. CLOSE
LOOK AT LATE DAY SATL IMAGE FROM YSTDY SHOWED MAIN BATCH OF SNOW
COVER OF 1-2 INCHES IN AREA BOUNDED BY KAWG-KDBQ-KVTI. TEMPS HAVE
BEEN JUST ABOVE FREEZING THIS REGION MOST OF NIGHT THUS SOME
CONTINUED MELT. BOTTOM LINE... DISCARDING NAM SOLUTION AND SIDING
WITH DEEPER MIXED GFS. GFS BUFR SOUNDINGS AND MSLP GRADIENT
SUPPORT WINDS GENERALLY 20-30 MPH WITH SOME HIGHER GUSTS. COULD
SEE A COUPLE SITES REACH LOW END ADVISORY CRITERIA MAINLY ON
SUSTAINED WINDS AOA 30 MPH... WHICH WAS OBSERVED YSTDY IN THE
PLAINS... BUT DOESN/T LOOK WIDESPREAD ENOUGH AND MARGINAL ATTIM TO
PRECLUDE ANY HEADLINES FOR WIND. GUSTY WINDS AND LOW RH VALUES
MAY INCREASE FIRE DANGER FOR DRY GRASS FUELS ELEVATED ABOVE THE
MELTING SNOW AND CONTINUE MENTION IN HWO AND GRAPHICAL WX STORY.
AS FOR HIGHS... GOING FCST LOOKS GOOD BASED OFF GFS BUFR SOUNDINGS
AND PROGGED LOW LEVEL THICKNESS AND VERIFICATION FROM YSTDY IN THE
PLAINS. EXPECT WIDESPREAD 60S... WITH COUPLE SITES POSSIBLY
NEAR 70 DEGS FAR SOUTH AND FEW 50S FAR N/NE. TNGT... UNSEASONABLY
MILD WITH SOUTH WINDS 15 TO 25 MPH AND INCREASE IN CLOUDS
SUPPORTING GOING ABOVE GUIDANCE ON MINS. SOME SUGGESTIONS OF MORE
WIDESPREAD 50S AND POSSIBLY NEEDING TO RAISE COUPLE MORE DEGS BUT
CONTINUE WITH GENERALLY U40S TO L50S. ..05..
LONG TERM...WEDNESDAY THROUGH NEXT MONDAY...
PRIMARY FOCUS IS ON RAIN AND THUNDERSTORM CHANCES WED...AND
ESPECIALLY WED NIGHT WITH THE COLD FRONTAL PASSAGE. STILL A LARGE
DEGREE OF UNCERTAINTY WITH THE NEXT POTENTIAL SYSTEM LATE IN THE
WEEKEND.
WEDNESDAY CERTAINLY LOOKS TO BE ANOTHER WINDY AND WARM DAY. THE
AMOUNT OF LOW LEVEL MOISTURE RETURN IS LIKELY OVERDONE IN THE
MODELS...BASED ON RECENT MODEL PERFORMANCE AND REAL TIME
VERIFICATION. THUS...SIMILAR TO THE THOUGHTS IN THE PREVIOUS
FORECAST...THE POTENTIAL FOR SHOWERS WILL BE LIMITED IN THE
EAST...BUT MORE LIKELY IN THE WEST IN THE AFTERNOON AS ISENTROPIC
LIFT DEVELOPS AND CONDENSATION PRESSURE DEFICITS LOWER. EVEN WITHOUT
WIDESPREAD LOW CLOUDS...INCREASING HIGH LEVEL MOISTURE SHOULD RESULT
IN MOSTLY CLOUDY SKIES AND LIMITED INSOLATION. THE PREFRONTAL
AIRMASS WILL EASILY SUPPORT TEMPERATURES IN THE UPPER 50S TO UPPER
60S...WHICH COULD POTENTIALLY BE EVEN WARMER IF CLOUD COVER IS THIN.
ALL OPERATIONAL MODELS...EXCEPT THE OUTLIER FASTER ECMWF...KEEP THE
COLD FRONT NORTHWEST OF THE FORECAST AREA DURING THE DAYTIME. SOUTH
TO SOUTHWEST WINDS SHOULD BE AT LEAST IN THE RANGE OF 20 TO 30 MPH
RANGE IN THE EAST...AND 15 TO 25 MPH RANGE IN THE WEST CLOSER TO THE
APPROACHING FRONT. MODELS CONTINUE TO PORTRAY A WARM AND DRY LAYER
AROUND 700 MB ABOVE THE MOISTENING LOW LEVELS...THAT SHOULD LIMIT
THE DEPTH OF ANY CONVECTION THAT DEVELOPS AS LOW LEVEL LAPSE RATES
STEEPEN. HAVE THUS LIMITED THE POTENTIAL FOR ISOLATED THUNDERSTORMS
TO THE WEST IN THE LATE AFTERNOON...WHERE 700 MB TEMPERATURES BEGIN
TO COOL.
WEDNESDAY NIGHT...WILL CONTINUE CATEGORICAL POPS FOR RAIN AS THE
COLD FRONT DRIVES SOUTHEAST THROUGH THE FORECAST AREA. GULF MOISTURE
CONVERGING ON THIS BOUNDARY IS SHOWN DRIVING PW VALUES TO AROUND 1
INCH BY 06Z OVER THE FORECAST AREA...AND HIGHER TRENDING ECMWF AND
GEM MODEL QPF LOOKS REASONABLE WITH WIDESPREAD HALF INCH EVENT
TOTALS. THERE WILL BE A PERIOD OF NEGATIVE THETAE LAPSE RATES OVER
ESPECIALLY THE SOUTH IN THE EVENING AND HAVE KEPT ISOLATED
THUNDERSTORM WORDING. FORECAST SOUNDINGS CONTINUE TO INDICATE A
POTENTIAL FOR A BRIEF PERIOD OF MIXED PRECIPITATION OR PERHAPS LIGHT
SNOW ALONG THE BACK EDGE OF THE SYSTEM AS IT WINDS DOWN IN THE NW
LATE. HAVE CONTINUED THIS TREND IN THE FORECAST BUT DO NOT
ANTICIPATE ANY ACCUMULATIONS. MODELS ARE IN DECENT AGREEMENT WITH
THE SURFACE COLD FRONT EXITING THE SOUTHEAST BY SUNRISE...WITH
SUNRISE MINS RANGING FROM THE UPPER 20S NORTHWEST TO THE LOWER 40S
SOUTHEAST.
SOME POST FRONTAL LIGHT RAIN MAY BE LINGERING IN THE SOUTH THU
MORNING. OTHERWISE...HIGH PRESSURE BUILDING INTO THE AREA SHOULD
PROVIDE MOSTLY CLEAR SKIES AND DAYTIME TEMPERATURES RETURNING CLOSER
TO MARCH NORMALS IN THE 40S BOTH THU AND FRI.
A DEVELOPING LOW LEVEL RETURN FLOW SHOULD MODERATE TEMPERATURES BACK
INTO THE 50S SATURDAY THROUGH MONDAY. OVERALL...MODELS CONTINUE TO
ADVERTISE A DEVELOPING UPPER LOW OVER THE SW U.S. LIFTING NORTHEAST
TO BRING PRECIPITATION TO THE LOCAL AREA SUNDAY INTO SUNDAY NIGHT.
THE GFS CONTINUES TO EXHIBIT THE POOREST RUN TO RUN CONTINUITY...AND
ALSO TRENDS FASTER AND MORE SOUTHEASTERLY WITH THE TRACK OF THIS
FEATURE. WHILE CONFIDENCE IN ANY GIVEN SOLUTION IS LOW...TRENDS AND
CONSENSUS SUPPORT CHANCE POPS FOR RAIN SUNDAY INTO SUNDAY
NIGHT...THEN SLIGHT TO LOW END CHANCES INTO MONDAY. ..SHEETS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
800 PM MST WED MAR 7 2012
.UPDATE...
ISSUED AT 752 PM MST WED MAR 7 2012
TONIGHT-THURSDAY NIGHT...18Z GFS/NAM/ECWMF AND MOST RECENT 00Z
NAM/RUC ALL SHOWING A MORE SOUTHERLY TRACK TO THE 500 LOW
CURRENTLY OVER EAST CENTRAL ARIZONA. 850-500 MOISTURE RATHER
LACKING TONIGHT EXCEPT ALONG THE HIGHER TERRAIN NEAR FLAGLER IN
EASTERN COLORADO BUT THAT WILL BE BRIEF AS IT CONTINUES TO MOVE
SOUTH AND OUT OF THE AREA. WILL NEED TO WATCH THE FAR
EAST/SOUTHEAST/SOUTH LATE TONIGHT AS RUC ONLY MODEL TO GENERATE
SOME LIGHT PRECIP AROUND 09Z DESPITE THE BETTER MOISTURE BEING
FURTHER SOUTH.
WITH THE MORE SOUTHERN TRACK MORE OF THE FORECAST AREA WILL SEE
PLENTIFUL SUNSHINE. WINDS WILL AGAIN BE FROM THE NORTH AT 15 TO 25
MPH. LATEST NAM/SREF 2M TEMPS AND MAV/MET MOS GUIDANCE ALL IN
AGREEMENT THAT AFTERNOON TEMPERATURES WILL PEAK GENERALLY IN THE
40S WITH A FEW 50S NEAR NORTON AND HILL CITY.
THURSDAY NIGHT...STILL LOOKS DRY. 00Z NAM TRIES TO INCREASE THE
LOW AND MID LEVEL MOISTURE ACROSS GREELEY AND WICHITA COUNTIES AS
THE UPPER LOW STARTS TO ROTATE INTO NORTHEAST NEW MEXICO/TEXAS
PANHANDLE. NOT MANY CHANGES MADE TO GRIDS DURING THIS PERIOD AT
PRESENT TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 212 PM MST WED MAR 7 2012
MAIN CONCERN WILL BE POSSIBILITY OF PRECIPITATION AND
PRECIPITATION TYPE. IN THE PAST 24 HRS...THERE HAS BEEN MUCH
UNCERTAINTY REGARDING PRECIP OVER THE AREA ASSOCIATED WITH THE
UPPER TROUGH WEST OF THE REGION...BUT THE GENERAL TREND HAS MADE
PRECIP LESS AND LESS LIKELY. BASED ON THIS TREND AND THE LATEST
GUIDANCE...HAVE LOWERED PROBABILITIES FURTHER...AND KEPT THE
HIGHEST CHANCES NEAREST TO THE TROUGH IN THE SOUTHWESTERN PART OF
THE AREA. NAM MODEL SOUNDINGS INDICATE THAT THERE IS STILL
POTENTIAL FOR A PERIOD OF FREEZING RAIN IN THE EARLY MORNING IF
ANY PRECIP WERE TO FALL...BUT SNOW SHOULD QUICKLY BECOME THE
PREDOMINANT PRECIP TYPE AS THE WESTERLY COMPONENT OF WINDS ALOFT
MODIFIES THE AIR MASS.
AS THE LOW MOVES FURTHER SOUTHEAST DURING THE DAYTIME ON
THURSDAY...THE CHANCE FOR PRECIP SHOULD MINIMIZE DURING THE
AFTERNOON HOURS. SKIES WILL CLEAR IN THE NORTHERN PORTION OF THE
AREA...ALLOWING WARMER TEMPERATURES IN THE NORTH COMPARED TO
FURTHER SOUTH. GUSTY NORTHERLY WINDS CAN BE EXPECTED DURING THE
DAYTIME DUE TO THE MOVEMENT AND POSITION OF THE TROUGH.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 212 PM MST WED MAR 7 2012
THERE ARE STILL SOME MODEL DIFFERENCES WITH THE UPPER LOW DURING
THIS TIMEFRAME. BOTH THE NAM/GFS BRING THE UPPER LOW INTO THE TEXAS
PANHANDLE THURSDAY NIGHT/FRIDAY. THE GFS HOLDS THE LOW IN THE TEXAS
PANHANDLE FRIDAY NIGHT WHILE THE NAM HAS IT POSITIONED A LITTLE
FURTHER NORTH IN THE OKLAHOMA PANHANDLE. BOTH HAVE THE GFS/NAM HAVE
THE UPPER LOW OVER THE OKLAHOMA PANHANDLE SATURDAY MORNING. THE GFS
TAKES THE LOW INTO CENTRAL KANSAS SATURDAY NIGHT. OTHER THAN
THURSDAY EVENING, LATE FRIDAY NIGHT AND SATURDAY BOTH MODELS KEEP
THE DYNAMICS/MOISTURE OUTSIDE OF THE FA. FOR THE PERIODS JUST
MENTIONED THERE IS SOME VERY MARGINAL MOISTURE OVER THE SOUTHEAST
FRINGE OF THE FA. FORECAST SOUNDINGS NEAR THE BEST PLAN VIEW
MOISTURE FIELD LOOK VERY DRY SO AM NOT OPTIMISTIC ABOUT ANY
MEASURABLE PRECIPITATION. FOR THIS REASON HAVE INCLUDED ONLY
SPRINKLES/FLURRIES THURSDAY EVENING AND LATE FRIDAY NIGHT. SOME
LIGHT RAIN MAY BE POSSIBLE IN THE FAR EAST SATURDAY MORNING.
OTHERWISE THE REMAINING PERIODS ARE DRY WITH NIL POPS.
MIN TEMPERATURES WILL MODERATE FROM THE LOWER 20S THURSDAY NIGHT TO
THE UPPER 20S/LOWER 30S FRIDAY/SATURDAY NIGHTS. MAX TEMPERATURES
WILL GENERALLY REACH THE MID 50S FRIDAY/SATURDAY.
FOR SUNDAY - WEDNESDAY...THE GFS SHOWS A RIDGE OVER THE FA SUNDAY
FOLLOWED BY WEST SOUTHWESTERLY FLOW MONDAY THROUGH WEDNESDAY.
LACK OF ANY SIGNIFICANT SHORTWAVE/FORCING WILL KEEP POPS NIL
THROUGH THIS PART OF THE FORECAST. 850MB TEMPERATURES INDICATE
THAT MAX TEMPERATURES SHOULD BE ABOUT 10 TO ALMOST 20 DEGREES
ABOVE NORMAL IN THE 60S TO AROUND 70. MIN TEMPERATURES IN THE
30S/LOW 40S WILL BE ABOUT 10 TO 15 DEGREES ABOVE NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 420 PM MST WED MAR 7 2012
VFR THROUGH THE PERIOD AT BOTH KGLD AND KMCK. STRATO-CU AT
4000-4500 FT EXPECTED AROUND THE KGLD TERMINAL BUT MORE DIRECTLY
IMPACTING THE KMCK TERMINAL THROUGH 06Z OR SO BEFORE AIRMASS
SLIDES SOUTH AWAY FROM THE AREA. RAPID CLEARING EXPECTED FROM
NORTH TO SOUTH EARLY THURSDAY MORNING WITH ONLY A FEW CIRRUS
CLOUDS EXPECTED SHORTLY THEREAFTER. NW-NE WINDS HAVE ALREADY LOST
THEIR GUSTS AS OF 23Z AND THROUGH 15Z SHOULD REMAIN IN THE 8-11KT
RANGE FROM THE N/NW. AROUND 15Z THURSDAY MIXING/HEATING WILL
PRODUCE 15G25KT WINDS FROM THE N.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...007
SHORT TERM...CJS
LONG TERM....FS
AVIATION...007
AREA FORECAST DISCUSSION
NWS WICHITA KS
536 PM CST WED MAR 7 2012
.UPDATE...
ADJUSTED THE SHORT TERM GRIDS TO BETTER REFLECT CURRENT OBSERVATIONS/
TRENDS. APPEARS THAT HRRR HAS BEST HANDLE ON FRONT/TIMING/TEMPERATURES
IN THE VERY SHORT TERM...WITH A BLEND INTO THE NAM LATER TONIGHT.
WILL LIKELY BE MAKING SOME TWEAKS TO POPS IN A BIT.
&&
.AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MAIN AVIATION CONCERNS ARE POTENTIAL THUNDERSTORMS THIS EVENING
AND MVFR CEILINGS AT KCNU LATER TONIGHT. THERE APPEARS TO BE A
NARROW WINDOW OF OPPORTUNITY FOR ELEVATED STORMS TO DEVELOP THIS
EVENING AT KICT/KCNU AND POSSIBLY AS FAR NORTH AS KHUT. NAM/RUC
MODEL FORECAST HAS 500+ J/G MUCAPE ACROSS SOUTH CENTRAL/SOUTHEAST
KS ROUGHLY BETWEEN 03-08 UTC. CEILINGS WILL DECREASE IN THE RAIN AT
KCNU WITH MVFR CEILINGS LOOKING LIKELY OVERNIGHT. SOME IMPROVEMENT
IS ANTICIPATED ALL SITES DURING THE DAY. -HOWERTON
&&
.PREV DISCUSSION... /ISSUED 317 PM CST WED MAR 7 2012/
DISCUSSION...
MAIN FORECAST CONCERN IS THE PRECIPITATION CHANCES THIS EVENING AND
LATER THIS WEEK.
SYNOPSIS:
A POTENT UPPER LEVEL TROUGH IS MOVING EASTWARD ACROSS THE
INTER-MOUNTAIN WEST. AT THE SURFACE A COLD FRONT IS MAKING ITS WAY
ACROSS KANSAS. AS OF 3PM THE FRONT IS APPROACHING WICHITA WHICH IS A
LITTLE AHEAD OF WHAT WAS PREVIOUSLY THOUGHT. TEMPERATURES HAVE
SURGED AHEAD OF THE FRONT AIDED BY THE GUSTY SOUTHERLY WINDS.
TONIGHT - SATURDAY:
THE UPPER TROUGH THAT ENTERED THE GREAT BASIN YESTERDAY HAS
SPLIT...WITH THE CUT OFF PORTION LOCATED OVER NORTHERN
ARIZONA/SOUTHERN UTAH...AND MOVING SLOWLY THROUGH THE FOUR CORNERS
AREA. LEE CYCLOGENESIS HAS A SURFACE LOW CURRENTLY OVER NEW MEXICO
WITH THE SURFACE TROUGH FOLLOWING THE COLD FRONT THROUGH KANSAS TO
THE GREAT LAKES REGION. GUSTY SOUTH WINDS TODAY HAVE ADVECTED MID TO
UPPER 50 DEWPOINTS TO THE SOUTHEASTERN TWO-THIRDS OF THE CWA.
AS THIS COLD FRONT MOVES SOUTHEAST THROUGH THE AREA THIS
EVENING...SHOWERS AND SCATTERED THUNDERSTORMS ARE LIKELY MAINLY
ALONG AND BEHIND THE FRONT. THE LATEST GUIDANCE CONTINUES TO SHOW THAT
PRECIPITATION WILL DEVELOP BEYOND 00Z THIS EVENING MAINLY OVER
SOUTHEASTERN KANSAS. SUFFICIENT INSTABILITY AND SHEAR MAY
SUPPORT A FEW STRONGER STORMS AND HAIL WITH THOSE CELLS...ESPECIALLY
NEAR THE KANSAS/OKLAHOMA. NORTHERN EXTENT OF THE PRECIPITATION
APPEARS TO BE GREATER WITH THE NAM THAN THE OTHER MODELS...THINK THE
PRECIPITATION WILL RESIDE MAINLY OVER SOUTH CENTRAL AND SOUTHEASTERN
KANSAS BUT THERE REMAINS A SLIGHT CHANCE OVER CENTRAL KANSAS.
THE UPPER LEVEL LOW STALLS OVER THE TEXAS PANHANDLE FOR THURSDAY
THROUGH SATURDAY...AND WILL PUSH ANOTHER SURGE OF MOISTURE NORTH
THROUGHOUT THE DAY SATURDAY. ONCE AGAIN THE SOUTHEASTERN TWO-THIRDS
ARE MORE FAVORED FOR THE PRECIPITATION SATURDAY...BUT THIS WILL HAVE
TO BE MONITORED. PRECIP TYPE SHOULD STAY MOSTLY LIQUID FORM...BUT
SLIGHT CHANCE THAT SOME COULD BE FREEZING DRIZZLE ON THE NORTHERN
FRINGES.
LAUGEMAN
SUNDAY - WEDNESDAY:
THE CUT OFF UPPER LOW WILL BE KICKED EASTWARD BY THE NEXT UPPER
LEVEL WAVE MOVING INTO THE NORTHWEST. PRECIPITATION WILL BE
POSSIBLE SUNDAY MORNING AS THE UPPER LOW LIFTS OVER THE AREA...BUT
CHANCES DO NOT LOOK TO BE HIGH. THE SYSTEM WILL EXIT BY SUNDAY
NIGHT AND WHILE ANOTHER DISTURBANCE WILL LIFT OVER US...IT LOOKS TO
BE FAR ENOUGH EAST TO KEEP PRECIPITATION CHANCES AT BAY. WARM AIR
ADVECTION THROUGH THE BEGINNING OF THE WEEK WILL HELP TEMPERATURES
REACH WELL ABOVE NORMAL THROUGH THE PERIOD.
BILLINGS
FIRE WEATHER...
THE GRASSLAND FIRE DANGER INDEX REMAINS VERY HIGH THROUGH THE REST
OF THIS AFTERNOON WITH GUSTY SOUTHERLY WINDS AHEAD OF THE
FRONT...BUT AS THE WINDS DECREASE THIS EVENING CONDITIONS WILL
IMPROVE. BEHIND THE COLD FRONT WINDS WILL AGAIN BE GUSTY DURING THE
DAY THURSDAY AND VERY HIGH FIRE DANGER WILL AGAIN BE POSSIBLE ACROSS
PORTIONS OF CENTRAL KANSAS. OTHERWISE WITH THE CHANCES FOR
PRECIPITATION AND LIGHTER WINDS DURING THE WEEKEND THE FIRE DANGER
INDEX WILL MAX OUT IN THE HIGH CATEGORY.
BILLINGS
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE MAIN AVIATION CONCERN IS THE STRONG WINDS...COLD FRONT TIMING
AND MVFR CONDITIONS POSSIBLE THIS AFTERNOON AND OVERNIGHT.
THE COLD FRONT AS OF 18Z HAS JUST REACHED KSLN AND IT WILL
CONTINUE A SLOW SOUTHWARD TREK THIS AFTERNOON/EVENING. EXPECT IT
TO REACH KICT AFTER 00Z. AHEAD OF THE FRONT SOUTHERLY WINDS ARE
VERY STRONG WITH SUSTAINED SPEEDS BETWEEN 25-30 KTS AND GUSTS
UPWARDS TO 35-40 KTS. AS THE FRONT APPROACHES AND MOVES THROUGH
WINDS WILL DECREASE AND BECOME NORTHERLY. NORTHERLY WINDS WILL BE
GUSTY...BUT NOT AS STRONG AS AHEAD OF THE FRONT. CEILINGS ARE
BOUNCING AROUND THE MVFR/VFR THRESHOLD IN THE 2500-3500 FT RANGE
AHEAD AND BEHIND THE FRONT. HAVE REMAINED SOMEWHAT PESSIMISTIC
WITH THE TAF FORECAST IN MVFR.
PRECIPITATION CHANCES INCREASE AS THE FRONT MOVES INTO SOUTHERN
KANSAS BETWEEN 02-06Z WHERE MOISTURE IS MORE PLENTIFUL. HAVE -SHRA
AT KICT AND KCNU WHERE CONFIDENCE IS HIGHEST...WITH VCSH POSSIBLE
AT ALL OTHER TERMINALS EXCEPT KRSL. COLDER AIR IS EXPECTED TO PUSH
INTO CENTRAL KANSAS...BUT HAVE KEPT FREEZING PRECIPITATION OUT OF
THE FORECAST AT THIS TIME AS THAT IS FURTHER OUT IN THE FORECAST
AND CONFIDENCE ON THAT FEATURE IS LOW.
BILLINGS
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 36 45 34 53 / 70 40 20 10
HUTCHINSON 35 46 32 53 / 50 30 20 10
NEWTON 35 46 33 53 / 50 40 10 10
ELDORADO 37 45 33 53 / 70 50 10 10
WINFIELD-KWLD 40 44 35 52 / 80 60 20 10
RUSSELL 31 49 29 54 / 20 10 10 10
GREAT BEND 32 48 29 53 / 20 10 20 10
SALINA 34 48 30 55 / 30 10 10 10
MCPHERSON 34 47 31 54 / 40 30 10 10
COFFEYVILLE 44 47 37 54 / 80 80 20 10
CHANUTE 39 45 34 55 / 80 70 10 10
IOLA 39 45 33 54 / 80 70 10 10
PARSONS-KPPF 42 44 35 54 / 80 70 20 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
236 PM CST TUE MAR 6 2012
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 359 AM CST TUE MAR 6 2012
SYNOPSIS:
WATER VAPOR LOOP AND LAST NIGHT`S RAOB ANALYSIS CONFIRMED THE
DEVELOPMENT OF SIGNIFICANT MID LEVEL TROUGH OVER THE PACIFIC
NORTHWEST REGION. 12-HR 500MB HEIGHT FALLS OF 130-170 METERS WERE
OBSERVED OVER WESTERN OREGON AND WASHINGTON. THE BASE OF THIS
TROUGH WAS CONTINUING TO DIG SOUTHEAST INTO NORTHERN CALIFORNIA AS
OF 09Z THIS MORNING. STRONG WEST-SOUTHWESTERLY MID LEVEL FLOW WAS
OCCURRING EAST OF THIS ACROSS THE GREAT BASIN REGION INTO THE
ROCKIES. THIS WAS RESULTING IN A LARGE AREA OF LOWER TROPOSPHERIC
WARMING WITH LOWER ELEVATION STATIONS ACROSS THE GREAT BASIN/ROCKIES
SEEING 850MB TEMPS IN THE MID TO UPPER TEENS. 700MB TEMPERATURES
WERE +4 TO +5C ACROSS ARIZONA AND NEW MEXICO. THE FRONT SEPARATING
THE COLD, POLAR AIRMASS FROM THE WARM INTERMOUNTAIN WEST AIRMASS WAS
POSITIONED FROM SOUTHWESTERN ALBERTA...EAST-SOUTHEASTWARD ALONG THE
CANADA-US BORDER TO A WEAK CYCLONIC CENTER AT 850MB NEAR THE
MANITOBA BORDER WITH MINNESOTA AND NORTH DAKOTA. STRONG SOUTHERLY
FLOW WAS NOTED ACROSS THE SOUTHERN PLAINS BETWEEN THE LEE-SIDE TROUGH
AND A GULF OF MEXICO HIGH.
TODAY:
THE VERY WARM AND DRY LOWER TROPOSPHERIC DOWNSLOPE AIRMASS WILL
YIELD ANOTHER UNSEASONABLY WARM DAY ACROSS SOUTHWEST KANSAS. GIVEN
THE RESULTS OF YESTERDAY AND AN EVEN WARMER THERMODYNAMIC
ENVIRONMENT TODAY...THERE IS MUCH MORE CONFIDENCE IN HIGHS TODAY
REACHING 80 DEGREES OVER A GOOD CHUNK OF SOUTHWEST KANSAS...AND HAVE
INCREASED THE MAXT GRID AS A RESULT. THE HRRR AND RUC MODELS WERE
USED AS THE PRIMARY GUIDANCE IN THE DEWPOINT/RH FORECAST FOR FIRE
WEATHER CONCERNS. DEWPOINTS WILL BE VERY LOW ACROSS THE
NORTHWESTERN 2/3RDS OF THE FORECAST AREA...IN THE 14 TO 20F
RANGE...AS TEMPERATURES RISE INTO THE UPPER 70S/NEAR 80. THIS WILL
RESULT IN RELATIVE HUMIDITY DOWN INTO THE 10 TO 15 PERCENT RANGE.
THE MAIN QUESTION REGARDING SIGNIFICANCE OF THE CRITICAL FIRE
WEATHER THREAT WILL BE WIND SPEED. HIGH RESOLUTION MODELS HAVE
TRENDED DOWNWARD IN THE WIND SPEED ACROSS THE VERY LOW RH AREAS FOR
THIS AFTERNOON...AND IT APPEARS THAT WIND SPEEDS WILL NOW BE RATHER
MARGINAL FOR CRITICAL FIRE WX. THE LATEST FORECAST WILL REFLECT 15
TO 20 MPH WINDS FOR MOST OF THE DAY...WITH 20 TO 25 MPH FOR ONLY A
COUPLE HOURS PROBABLY BY LATE AFTERNOON. GUSTS ARE STILL
ANTICIPATED TO BE 25 TO 30 MPH. FARTHER EAST WHERE THE MSLP
GRADIENT WILL BE TIGHTER...WINDS WILL BE FAIRLY STRONG AND APPROACH
WIND ADVISORY CATEGORY. HAVE DECIDED TO NOT ISSUE A WIND ADVISORY
IN THE SOUTH CENTRAL KANSAS COUNTIES GIVEN THE UNCERTAINTY IN DEEP
MIXING...BUT THE REALLY DEEP MIXING MAY NOT REALLY MATTER MUCH AND
WIND ADVISORY LEVEL WINDS (SUSTAINED 30 MPH) MAY STILL BE REACHED
ACROSS PRATT-COMANCHE-BARBER COUNTIES.
TONIGHT:
AS THE UPPER TROUGH CONTINUES TO DIG SOUTHEAST LATE TODAY AND
TONIGHT...THE FRONT (MENTIONED IN THE SYNOPSIS PARAGRAPH) WILL BEGIN
ITS EQUATORWARD PUSH. THE FRONT IS EXPECTED TO REACH FAR NORTHWEST
KANSAS AROUND 09Z TONIGHT. AHEAD OF THE FRONT IN SOUTHWEST
KANSAS...WIND SPEEDS WILL STAY FAIRLY STRONG BY NOCTURNAL STANDARDS
WITH SPEEDS AVERAGING 20 TO 30 MPH THROUGH MOST OF THE
NIGHT...ESPECIALLY THE SOUTHEAST HALF OF THE FORECAST AREA. THIS
WILL KEEP TEMPERATURES ABNORMALLY WARM THROUGH THE NIGHT WITH 06-12Z
TEMPERATURES IN THE LOWER 50S FOR A GOOD PORTION OF THE FORECAST
AREA. LOW LEVEL MOISTURE WILL ALSO BEGIN TO MOVE INTO THE
SOUTHEASTERN COUNTIES WITH DEWPOINT TEMPERATURES RISING INTO THE
UPPER 40S TO NEAR 50 (PARTICULARLY ACROSS BARBER COUNTY). THE
DEVELOPMENT OF LOW STRATUS WILL HAVE TO BE WATCHED...BUT AT THIS
TIME THE MAJORITY OF INITIAL LOW LEVEL CLOUD COVER TOWARD DAYBREAK
WEDNESDAY WILL BE ACROSS OKLAHOMA AND AREAS OF SOUTH CENTRAL KANSAS
JUST EAST OF BARBER COUNTY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 233 PM CST TUE MAR 6 2012
WARM AIR ADVECTION AND ISENTROPIC LIFT IMPROVES ACROSS SOUTH CENTRAL
AND MUCH OF SOUTHWEST KANSAS WEDNESDAY NIGHT AS COLDER AIR NEAR THE
SURFACE RETURNS BEHIND A COLD FRONT. MODEL SOUNDINGS ACROSS
SOUTHWEST AND SOUTH CENTRAL KANSAS INDICATING A FAIRLY DEEP LAYER OF
LOW LEVEL MOISTURE DEVELOPING BY 12Z THURSDAY...HOWEVER LITTLE
MOISTURE IS PRESENT IN THE ICE CRYSTAL GROWTH ZONE. THIS WOULD
SUPPORT MORE DRIZZLE/FREEZING DRIZZLE THAN SNOW SO THE MAIN QUESTION
WILL BE THE TEMPERATURES NEAR THE SURFACE AS THIS PRECIPITATION
FALLS. AT THIS TIME THE NAM WAS COLDER THAN ALL THE MODELS NEAR THE
SURFACE AND THE 2 METER TEMPERATURE BETWEEN 18Z THURSDAY AND 00Z
FRIDAY SUGGESTED AFTERNOON TEMPERATURES WILL BE AROUND 32 DEGREES
FOR MUCH OF WESTERN KANSAS. AM CURRENTLY LEANING TOWARDS THESE
COLDER TEMPERATURES THURSDAY AFTERNOON BASED ON EXPECTED CLOUD
COVER, POSSIBLE PRECIPITATION AND COLD AIR ADVECTION ADVERTISED BY
ALL THE MODELS ACROSS SOUTHWEST KANSAS. BASED ON THESE SURFACE
TEMPERATURES LATE WEDNESDAY NIGHT AND THURSDAY THERE APPEARS TO BE
CHANCE FOR A PROLONGED PERIOD LIGHT/VERY LIGHT FREEZING DRIZZLE
ACROSS POTIONS OF SOUTHWEST KANSAS DURING THE DAY. CURRENTLY IT
APPEARS THAT PRECIPITATION DURING THIS FREEZING DRIZZLE TIME FRAME
WILL BE LIGHT (LESS THAN 0.05INCHES) SO WILL NOT BE ISSUING A WATCH OR
ADVISORY. DO HOWEVER EXPECT THIS PROLONGED PERIOD OF LIGHT
PRECIPITATION WILL PRODUCE SOME SLICK SPOTS ON SOME ELEVATED
SURFACES.
ON FRIDAY AND EARLY SATURDAY AN UPPER LOW WILL CONTINUE TO WOBBLE
ACROSS NEW MEXICO AS A SERIES OF UPPER LEVEL DISTURBANCE ROTATES
AROUND THIS SYSTEM. THE ECMWF, GEM, SREF MEAN, AND GFS ALL CONTINUE
TO STRUGGLE WITH THE MOVEMENT OF THIS CUTOFF UPPER LOW AND
CONFIDENCE IS NOT HIGH WITH WHICH ONE IS MORE CORRECT. AT THIS TIME
GIVEN THAT THE GFS AT 12Z WEDNESDAY UNDERESTIMATED THE UPPER LEVEL
JET STREAK WEST OF THIS SYSTEM AM CURRENTLY TRENDING TOWARD A SLOWER
AND FURTHER SOUTH SOLUTION WHICH THE 00Z ECMWF,12Z GEM AND MEAN SREF
INDICATED. WITH THIS IN MIND WILL HOLD ON TO THE PRECIPITATION
CHANCES THROUGH THE WEEKEND AS MOISTURE AND WEAK LIFT PERSISTS
ACROSS WESTERN KANSAS AHEAD OF THIS SLOW MOVING UPPER LEVEL SYSTEM.
BY LATE THIS WEEKEND ALL THE MODELS BEGIN TO MOVE THIS SYSTEM EAST
OF WESTERN KANSAS ALLOWING A UPPER LEVEL RIDGE TO BUILD INTO THE
WESTERN HIGH PLAINS. MAGNITUDE AND TIMING OF THIS RIDGING STILL
UNCLEAR BUT A WARMING TREND SHOULD BEGIN EARLY NEXT WEEK. 850MB
TEMPERATURE TRENDS CONTINUE TO SUPPORT HIGHS REBOUNDING BACK INTO
THE 60S BY AS EARLY AS MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1119 AM CST TUE MAR 6 2012
LOOK FOR STRONGER WINDS TO MIX TO THE SURFACE THIS AFTERNOON WITH
SOUTH TO SOUTHWEST WINDS OF 20 TO 30KT AND ONLY A FEW CIRRUS.
TONIGHT A LOW LEVEL JET OF 50 TO 55KTS AT H85 WILL DEVELOP WITH
SURFACE WINDS STAYING IN THE 15 TO 25 MPH RANGE. A STRONG COLD
FRONT WILL SWITCH WINDS TO THE NORTH AROUND DODGE CITY BY NOON
TO 1 PM WEDNESDAY AND AROUND 9 TO 10 AM AT HAYS. WINDS WILL SHIFT
ABRUPTLY NORTH AT 20 TO 30KTS WITH THE FROPA THEN SLACKEN DURING
THE DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 51 66 28 33 / 10 30 70 80
GCK 49 53 27 33 / 10 20 60 60
EHA 47 65 25 33 / 0 20 60 60
LBL 50 66 29 33 / 10 20 70 70
HYS 51 53 28 38 / 10 40 40 40
P28 55 68 35 36 / 20 70 80 80
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 7 PM CST /6 PM MST/ THIS EVENING FOR
KSZ030-031-043>046-061>065-074>078-084>087.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM....BURGERT
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1125 AM CST TUE MAR 6 2012
...UPDATED FOR AVIATION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 359 AM CST TUE MAR 6 2012
SYNOPSIS:
WATER VAPOR LOOP AND LAST NIGHT`S RAOB ANALYSIS CONFIRMED THE
DEVELOPMENT OF SIGNIFICANT MID LEVEL TROUGH OVER THE PACIFIC
NORTHWEST REGION. 12-HR 500MB HEIGHT FALLS OF 130-170 METERS WERE
OBSERVED OVER WESTERN OREGON AND WASHINGTON. THE BASE OF THIS
TROUGH WAS CONTINUING TO DIG SOUTHEAST INTO NORTHERN CALIFORNIA AS
OF 09Z THIS MORNING. STRONG WEST-SOUTHWESTERLY MID LEVEL FLOW WAS
OCCURRING EAST OF THIS ACROSS THE GREAT BASIN REGION INTO THE
ROCKIES. THIS WAS RESULTING IN A LARGE AREA OF LOWER TROPOSPHERIC
WARMING WITH LOWER ELEVATION STATIONS ACROSS THE GREAT BASIN/ROCKIES
SEEING 850MB TEMPS IN THE MID TO UPPER TEENS. 700MB TEMPERATURES
WERE +4 TO +5C ACROSS ARIZONA AND NEW MEXICO. THE FRONT SEPARATING
THE COLD, POLAR AIRMASS FROM THE WARM INTERMOUNTAIN WEST AIRMASS WAS
POSITIONED FROM SOUTHWESTERN ALBERTA...EAST-SOUTHEASTWARD ALONG THE
CANADA-US BORDER TO A WEAK CYCLONIC CENTER AT 850MB NEAR THE
MANITOBA BORDER WITH MINNESOTA AND NORTH DAKOTA. STRONG SOUTHERLY
FLOW WAS NOTED ACROSS THE SOUTHERN PLAINS BETWEEN THE LEE-SIDE TROUGH
AND A GULF OF MEXICO HIGH.
TODAY:
THE VERY WARM AND DRY LOWER TROPOSPHERIC DOWNSLOPE AIRMASS WILL
YIELD ANOTHER UNSEASONABLY WARM DAY ACROSS SOUTHWEST KANSAS. GIVEN
THE RESULTS OF YESTERDAY AND AN EVEN WARMER THERMODYNAMIC
ENVIRONMENT TODAY...THERE IS MUCH MORE CONFIDENCE IN HIGHS TODAY
REACHING 80 DEGREES OVER A GOOD CHUNK OF SOUTHWEST KANSAS...AND HAVE
INCREASED THE MAXT GRID AS A RESULT. THE HRRR AND RUC MODELS WERE
USED AS THE PRIMARY GUIDANCE IN THE DEWPOINT/RH FORECAST FOR FIRE
WEATHER CONCERNS. DEWPOINTS WILL BE VERY LOW ACROSS THE
NORTHWESTERN 2/3RDS OF THE FORECAST AREA...IN THE 14 TO 20F
RANGE...AS TEMPERATURES RISE INTO THE UPPER 70S/NEAR 80. THIS WILL
RESULT IN RELATIVE HUMIDITY DOWN INTO THE 10 TO 15 PERCENT RANGE.
THE MAIN QUESTION REGARDING SIGNIFICANCE OF THE CRITICAL FIRE
WEATHER THREAT WILL BE WIND SPEED. HIGH RESOLUTION MODELS HAVE
TRENDED DOWNWARD IN THE WIND SPEED ACROSS THE VERY LOW RH AREAS FOR
THIS AFTERNOON...AND IT APPEARS THAT WIND SPEEDS WILL NOW BE RATHER
MARGINAL FOR CRITICAL FIRE WX. THE LATEST FORECAST WILL REFLECT 15
TO 20 MPH WINDS FOR MOST OF THE DAY...WITH 20 TO 25 MPH FOR ONLY A
COUPLE HOURS PROBABLY BY LATE AFTERNOON. GUSTS ARE STILL
ANTICIPATED TO BE 25 TO 30 MPH. FARTHER EAST WHERE THE MSLP
GRADIENT WILL BE TIGHTER...WINDS WILL BE FAIRLY STRONG AND APPROACH
WIND ADVISORY CATEGORY. HAVE DECIDED TO NOT ISSUE A WIND ADVISORY
IN THE SOUTH CENTRAL KANSAS COUNTIES GIVEN THE UNCERTAINTY IN DEEP
MIXING...BUT THE REALLY DEEP MIXING MAY NOT REALLY MATTER MUCH AND
WIND ADVISORY LEVEL WINDS (SUSTAINED 30 MPH) MAY STILL BE REACHED
ACROSS PRATT-COMANCHE-BARBER COUNTIES.
TONIGHT:
AS THE UPPER TROUGH CONTINUES TO DIG SOUTHEAST LATE TODAY AND
TONIGHT...THE FRONT (MENTIONED IN THE SYNOPSIS PARAGRAPH) WILL BEGIN
ITS EQUATORWARD PUSH. THE FRONT IS EXPECTED TO REACH FAR NORTHWEST
KANSAS AROUND 09Z TONIGHT. AHEAD OF THE FRONT IN SOUTHWEST
KANSAS...WIND SPEEDS WILL STAY FAIRLY STRONG BY NOCTURNAL STANDARDS
WITH SPEEDS AVERAGING 20 TO 30 MPH THROUGH MOST OF THE
NIGHT...ESPECIALLY THE SOUTHEAST HALF OF THE FORECAST AREA. THIS
WILL KEEP TEMPERATURES ABNORMALLY WARM THROUGH THE NIGHT WITH 06-12Z
TEMPERATURES IN THE LOWER 50S FOR A GOOD PORTION OF THE FORECAST
AREA. LOW LEVEL MOISTURE WILL ALSO BEGIN TO MOVE INTO THE
SOUTHEASTERN COUNTIES WITH DEWPOINT TEMPERATURES RISING INTO THE
UPPER 40S TO NEAR 50 (PARTICULARLY ACROSS BARBER COUNTY). THE
DEVELOPMENT OF LOW STRATUS WILL HAVE TO BE WATCHED...BUT AT THIS
TIME THE MAJORITY OF INITIAL LOW LEVEL CLOUD COVER TOWARD DAYBREAK
WEDNESDAY WILL BE ACROSS OKLAHOMA AND AREAS OF SOUTH CENTRAL KANSAS
JUST EAST OF BARBER COUNTY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 359 AM CST TUE MAR 6 2012
THE EXTENDED PERIOD BEGINS 12Z WEDNESDAY. LOTS OF WEATHER TO
CONSIDER, HOWEVER, THIS AFD SECTION WILL BE SLIGHTLY ABBREVIATED DUE
TO MOST OF THE TIME WAS SPENT ON THE GRIDS MAKING NUMEROUS
MODIFICATIONS. OVERALL, THE EXTENDED PERIOD RELIED HEAVILY ON THE
00Z ECMWF FOR THE SYNOPTIC PATTERN AND USED 00Z NAM FOR
THERMODYNAMICS. THE 00Z GFS WAS COMPLETELY DISMISSED AS IT IS A
CLEAR OUTLIER COMPARED TO THE ECMWF/NAM/GEM/UKMET.
WEDNESDAY:
ON WEDNESDAY, A SIGNIFICANT COLD FRONT WILL BE TRAVERSING ACROSS THE
REGION. HAVE ADOPTED A NON DIURNAL TEMPERATURE CURVE WITH A FIRST
GUESS FROM THE NAM AS PEAK HEATING WILL OCCUR NEAR THE NORMAL
AFTERNOON HOURS TOWARDS MEDICINE LODGE, HOWEVER AT SCOTT CITY TO
HAYS, MAX TEMPERATURES WILL BE REACHED EARLY AND THEN FALL LIKE A
ROCK AS THE FRONT MOVES THROUGH.
MOST OF THE DAY WEDNESDAY SHOULD REMAIN DRY, EXCEPT ACROSS SOUTH
CENTRAL KANSAS WHERE WARM AIR ADVECTION AND ISENTROPIC LIFT COULD
PROVIDE THIS REGION WITH DRIZZLE. BY WEDNESDAY EVENING INTO THURSDAY
MORNING, A VORTMAX WILL SLIDE ACROSS THE REGION WITH SIGNIFICANT
HEIGHT FALLS AND RELATED AGEOSTROPHIC MOTIONS (DYNAMIC LIFT)
SPREADING ACROSS SOUTHWEST KANSAS. THIS DYNAMIC PROCESS WILL BE
ENOUGH TO CAUSE RAIN AND ISOLATED THUNDERSTORMS ACROSS SOUTH CENTRAL
KANSAS. ECMWF CAPE IS NOT PARTICULARLY IMPRESSIVE, HOWEVER, MID
LEVEL LAPSE RATES WILL CONTINUE TO STEEPEN SO THINK THERE WILL BE
ENOUGH INSTABILITY IN THE LOW TO MIDDLE PORTION OF THE ATMOSPHERE TO
PRODUCE SOME LIGHTNING. SEVERE WEATHER IS NOT ANTICIPATED AS ANY
CONVECTION WILL LIKE PEAK OVERNIGHT WITH SURFACE BASE INSTABILITY IS
AT A MINIMUM. PLUS, THE CONVECTION WILL BE ELEVATED. PERHAPS SOME
MARGINAL HAIL COULD OCCUR AT MEDICINE LODGE GIVEN THE AFOREMENTIONED
STEEP LAPSE RATES BUT IT IS TOO EARLY TO TELL.
MEANWHILE, THROUGH THE OVERNIGHT WEDNESDAY AND INTO THURSDAY,
SIGNIFICANT COLD AIR ADVECTION WILL BE OCCURRING ON THE BACKSIDE OF
OF 850-700 HPA TROUGH. RIGHT NOW, I HAVE EMPLOYED THE PROBABILITY OF
WEATHER TYPE TOOL FROM THE ESTF SMART TOOL REPOSITORY AND HAVE USED
THE NAM FOR A THERMODYNAMIC BACKGROUND. WOULD PREFER NOT TO USE
THIS MESOSCALE MODEL AT THIS TIME RANGE, HOWEVER, THE ECMWF HAS LOW
RESOLUTION IN THE VERTICAL AND CANNOT BE USED TO DETERMINE
PRECIPITATION TYPE. THE POWT ACTUALLY PRODUCED FAIRLY REASONABLE
LOOKING PRECIPITATION TYPE GRIDS AND I PARTICULARLY LIKE THE
TRANSITION THROUGH THE OVERNIGHT HOURS. THERE WILL BE A ZONE ACROSS
THE FORECAST AREA WHERE THE TOP DOWN METHOD AND FORECAST SOUNDINGS
SHOW THAT FREEZING RAIN COULD BE HAPPEN. RIGHT NOW, I WAS
CONSERVATIVE ON ICE ACCUMULATION AMOUNTS BUT IF THIS ZR AREA WERE TO
EXPAND WITH ELEVATED SHOWERS/CONVECTION ON TOP OF A SHALLOW COLD AIR
MASS...TREACHEROUS COMMUTING CONDITIONS WILL CERTAINLY BE A
POSSIBILITY. IT IS TOO EARLY TO MENTION A WINTER STORM WATCH, BUT AN
ICE STORM WARNING CANNOT BE COMPLETELY DISMISSED AT THIS POINT BASED
OFF 00Z DATA THAT WAS ANALYZED.
THURSDAY:
FOR THURSDAY, THE COUNTY WARNING AREA WILL CONTINUE TO BE IN THE
TRANSITION ZONE FOR PRECIPITATION TYPES. SNOW LOOKS LIKELY ACROSS MY
NORTHWEST COUNTIES WHERE RAIN LOOKS LIKELY ACROSS SOUTH CENTRAL
KANSAS. THE ECMWF IS MORE AGGRESSIVE WITH COLD AIR ADVECTION THROUGH
THE 850-700 HPA LAYER COMPARED TO THE NAM WHICH WANTS TO KEEP THE
WARM NOSE LINGERING AROUND, PARTICULARLY ACROSS SOUTH CENTRAL
KANSAS. AS MENTIONED BEFORE, WENT AHEAD AND USED THE NAM THERMO
FIELDS FOR PRECIPITATION TYPES ALTHOUGH THE ECMWF COULD BE MORE
CORRECT IN CONTINUING TO DRIVE THE COLD AIR SOUTHWARD THROUGH THE
DAY. ALL THESE DETAILS WILL BE HAMMERED OUT AS THE EVENT APPROACHES.
FRIDAY AND BEYOND:
DUE TO TIME CONSTRAINTS, DID NOT DEVIATE FROM THE ALLBLEND APPROACH.
THERE IS TOO MUCH UNCERTAINTY IN WHAT WILL HAPPEN WITH THE UPPER
LEVEL WAVE. THE ECMWF/GEM KEEPS THE WAVE CLOSER TO OUR AREA WHICH
WOULD PROVIDE THE REGION WITH A CHANCE OF SHOWERS AND SNOW SHOWERS.
THE GFS IS VERY PROGRESSIVE BUT AS MENTIONED ABOVE WAS DISCOUNTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1119 AM CST TUE MAR 6 2012
LOOK FOR STRONGER WINDS TO MIX TO THE SURFACE THIS AFTERNOON WITH
SOUTH TO SOUTHWEST WINDS OF 20 TO 30KT AND ONLY A FEW CIRRUS.
TONIGHT A LOW LEVEL JET OF 50 TO 55KTS AT H85 WILL DEVELOP WITH
SURFACE WINDS STAYING IN THE 15 TO 25 MPH RANGE. A STRONG COLD
FRONT WILL SWITCH WINDS TO THE NORTH AROUND DODGE CITY BY NOON
TO 1 PM WEDNESDAY AND AROUND 9 TO 10 AM AT HAYS. WINDS WILL SHIFT
ABRUPTLY NORTH AT 20 TO 30KTS WITH THE FROPA THEN SLACKEN DURING
THE DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 80 47 66 27 / 0 10 30 60
GCK 80 44 55 27 / 0 10 20 60
EHA 81 44 59 24 / 0 0 20 60
LBL 81 46 65 27 / 0 10 20 60
HYS 79 47 55 27 / 0 10 40 60
P28 75 52 69 34 / 0 20 70 80
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 7 PM CST /6 PM MST/ THIS EVENING FOR
KSZ030-031-043>046-061>065-074>078-084>087.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM....SUGDEN
AVIATION...KRUSE
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
500 AM CST TUE MAR 6 2012
...UPDATE TO AVIATION FOR 12Z TAFS...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 359 AM CST TUE MAR 6 2012
SYNOPSIS:
WATER VAPOR LOOP AND LAST NIGHT`S RAOB ANALYSIS CONFIRMED THE
DEVELOPMENT OF SIGNIFICANT MID LEVEL TROUGH OVER THE PACIFIC
NORTHWEST REGION. 12-HR 500MB HEIGHT FALLS OF 130-170 METERS WERE
OBSERVED OVER WESTERN OREGON AND WASHINGTON. THE BASE OF THIS
TROUGH WAS CONTINUING TO DIG SOUTHEAST INTO NORTHERN CALIFORNIA AS
OF 09Z THIS MORNING. STRONG WEST-SOUTHWESTERLY MID LEVEL FLOW WAS
OCCURRING EAST OF THIS ACROSS THE GREAT BASIN REGION INTO THE
ROCKIES. THIS WAS RESULTING IN A LARGE AREA OF LOWER TROPOSPHERIC
WARMING WITH LOWER ELEVATION STATIONS ACROSS THE GREAT BASIN/ROCKIES
SEEING 850MB TEMPS IN THE MID TO UPPER TEENS. 700MB TEMPERATURES
WERE +4 TO +5C ACROSS ARIZONA AND NEW MEXICO. THE FRONT SEPARATING
THE COLD, POLAR AIRMASS FROM THE WARM INTERMOUNTAIN WEST AIRMASS WAS
POSITIONED FROM SOUTHWESTERN ALBERTA...EAST-SOUTHEASTWARD ALONG THE
CANADA-US BORDER TO A WEAK CYCLONIC CENTER AT 850MB NEAR THE
MANITOBA BORDER WITH MINNESOTA AND NORTH DAKOTA. STRONG SOUTHERLY
FLOW WAS NOTED ACROSS THE SOUTHERN PLAINS BETWEEN THE LEE-SIDE TROUGH
AND A GULF OF MEXICO HIGH.
TODAY:
THE VERY WARM AND DRY LOWER TROPOSPHERIC DOWNSLOPE AIRMASS WILL
YIELD ANOTHER UNSEASONABLY WARM DAY ACROSS SOUTHWEST KANSAS. GIVEN
THE RESULTS OF YESTERDAY AND AN EVEN WARMER THERMODYNAMIC
ENVIRONMENT TODAY...THERE IS MUCH MORE CONFIDENCE IN HIGHS TODAY
REACHING 80 DEGREES OVER A GOOD CHUNK OF SOUTHWEST KANSAS...AND HAVE
INCREASED THE MAXT GRID AS A RESULT. THE HRRR AND RUC MODELS WERE
USED AS THE PRIMARY GUIDANCE IN THE DEWPOINT/RH FORECAST FOR FIRE
WEATHER CONCERNS. DEWPOINTS WILL BE VERY LOW ACROSS THE
NORTHWESTERN 2/3RDS OF THE FORECAST AREA...IN THE 14 TO 20F
RANGE...AS TEMPERATURES RISE INTO THE UPPER 70S/NEAR 80. THIS WILL
RESULT IN RELATIVE HUMIDITY DOWN INTO THE 10 TO 15 PERCENT RANGE.
THE MAIN QUESTION REGARDING SIGNIFICANCE OF THE CRITICAL FIRE
WEATHER THREAT WILL BE WIND SPEED. HIGH RESOLUTION MODELS HAVE
TRENDED DOWNWARD IN THE WIND SPEED ACROSS THE VERY LOW RH AREAS FOR
THIS AFTERNOON...AND IT APPEARS THAT WIND SPEEDS WILL NOW BE RATHER
MARGINAL FOR CRITICAL FIRE WX. THE LATEST FORECAST WILL REFLECT 15
TO 20 MPH WINDS FOR MOST OF THE DAY...WITH 20 TO 25 MPH FOR ONLY A
COUPLE HOURS PROBABLY BY LATE AFTERNOON. GUSTS ARE STILL
ANTICIPATED TO BE 25 TO 30 MPH. FARTHER EAST WHERE THE MSLP
GRADIENT WILL BE TIGHTER...WINDS WILL BE FAIRLY STRONG AND APPROACH
WIND ADVISORY CATEGORY. HAVE DECIDED TO NOT ISSUE A WIND ADVISORY
IN THE SOUTH CENTRAL KANSAS COUNTIES GIVEN THE UNCERTAINTY IN DEEP
MIXING...BUT THE REALLY DEEP MIXING MAY NOT REALLY MATTER MUCH AND
WIND ADVISORY LEVEL WINDS (SUSTAINED 30 MPH) MAY STILL BE REACHED
ACROSS PRATT-COMANCHE-BARBER COUNTIES.
TONIGHT:
AS THE UPPER TROUGH CONTINUES TO DIG SOUTHEAST LATE TODAY AND
TONIGHT...THE FRONT (MENTIONED IN THE SYNOPSIS PARAGRAPH) WILL BEGIN
ITS EQUATORWARD PUSH. THE FRONT IS EXPECTED TO REACH FAR NORTHWEST
KANSAS AROUND 09Z TONIGHT. AHEAD OF THE FRONT IN SOUTHWEST
KANSAS...WIND SPEEDS WILL STAY FAIRLY STRONG BY NOCTURNAL STANDARDS
WITH SPEEDS AVERAGING 20 TO 30 MPH THROUGH MOST OF THE
NIGHT...ESPECIALLY THE SOUTHEAST HALF OF THE FORECAST AREA. THIS
WILL KEEP TEMPERATURES ABNORMALLY WARM THROUGH THE NIGHT WITH 06-12Z
TEMPERATURES IN THE LOWER 50S FOR A GOOD PORTION OF THE FORECAST
AREA. LOW LEVEL MOISTURE WILL ALSO BEGIN TO MOVE INTO THE
SOUTHEASTERN COUNTIES WITH DEWPOINT TEMPERATURES RISING INTO THE
UPPER 40S TO NEAR 50 (PARTICULARLY ACROSS BARBER COUNTY). THE
DEVELOPMENT OF LOW STRATUS WILL HAVE TO BE WATCHED...BUT AT THIS
TIME THE MAJORITY OF INITIAL LOW LEVEL CLOUD COVER TOWARD DAYBREAK
WEDNESDAY WILL BE ACROSS OKLAHOMA AND AREAS OF SOUTH CENTRAL KANSAS
JUST EAST OF BARBER COUNTY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 359 AM CST TUE MAR 6 2012
THE EXTENDED PERIOD BEGINS 12Z WEDNESDAY. LOTS OF WEATHER TO
CONSIDER, HOWEVER, THIS AFD SECTION WILL BE SLIGHTLY ABBREVIATED DUE
TO MOST OF THE TIME WAS SPENT ON THE GRIDS MAKING NUMEROUS
MODIFICATIONS. OVERALL, THE EXTENDED PERIOD RELIED HEAVILY ON THE
00Z ECMWF FOR THE SYNOPTIC PATTERN AND USED 00Z NAM FOR
THERMODYNAMICS. THE 00Z GFS WAS COMPLETELY DISMISSED AS IT IS A
CLEAR OUTLIER COMPARED TO THE ECMWF/NAM/GEM/UKMET.
WEDNESDAY:
ON WEDNESDAY, A SIGNIFICANT COLD FRONT WILL BE TRAVERSING ACROSS THE
REGION. HAVE ADOPTED A NON DIURNAL TEMPERATURE CURVE WITH A FIRST
GUESS FROM THE NAM AS PEAK HEATING WILL OCCUR NEAR THE NORMAL
AFTERNOON HOURS TOWARDS MEDICINE LODGE, HOWEVER AT SCOTT CITY TO
HAYS, MAX TEMPERATURES WILL BE REACHED EARLY AND THEN FALL LIKE A
ROCK AS THE FRONT MOVES THROUGH.
MOST OF THE DAY WEDNESDAY SHOULD REMAIN DRY, EXCEPT ACROSS SOUTH
CENTRAL KANSAS WHERE WARM AIR ADVECTION AND ISENTROPIC LIFT COULD
PROVIDE THIS REGION WITH DRIZZLE. BY WEDNESDAY EVENING INTO THURSDAY
MORNING, A VORTMAX WILL SLIDE ACROSS THE REGION WITH SIGNIFICANT
HEIGHT FALLS AND RELATED AGEOSTROPHIC MOTIONS (DYNAMIC LIFT)
SPREADING ACROSS SOUTHWEST KANSAS. THIS DYNAMIC PROCESS WILL BE
ENOUGH TO CAUSE RAIN AND ISOLATED THUNDERSTORMS ACROSS SOUTH CENTRAL
KANSAS. ECMWF CAPE IS NOT PARTICULARLY IMPRESSIVE, HOWEVER, MID
LEVEL LAPSE RATES WILL CONTINUE TO STEEPEN SO THINK THERE WILL BE
ENOUGH INSTABILITY IN THE LOW TO MIDDLE PORTION OF THE ATMOSPHERE TO
PRODUCE SOME LIGHTNING. SEVERE WEATHER IS NOT ANTICIPATED AS ANY
CONVECTION WILL LIKE PEAK OVERNIGHT WITH SURFACE BASE INSTABILITY IS
AT A MINIMUM. PLUS, THE CONVECTION WILL BE ELEVATED. PERHAPS SOME
MARGINAL HAIL COULD OCCUR AT MEDICINE LODGE GIVEN THE AFOREMENTIONED
STEEP LAPSE RATES BUT IT IS TOO EARLY TO TELL.
MEANWHILE, THROUGH THE OVERNIGHT WEDNESDAY AND INTO THURSDAY,
SIGNIFICANT COLD AIR ADVECTION WILL BE OCCURRING ON THE BACKSIDE OF
OF 850-700 HPA TROUGH. RIGHT NOW, I HAVE EMPLOYED THE PROBABILITY OF
WEATHER TYPE TOOL FROM THE ESTF SMART TOOL REPOSITORY AND HAVE USED
THE NAM FOR A THERMODYNAMIC BACKGROUND. WOULD PREFER NOT TO USE
THIS MESOSCALE MODEL AT THIS TIME RANGE, HOWEVER, THE ECMWF HAS LOW
RESOLUTION IN THE VERTICAL AND CANNOT BE USED TO DETERMINE
PRECIPITATION TYPE. THE POWT ACTUALLY PRODUCED FAIRLY REASONABLE
LOOKING PRECIPITATION TYPE GRIDS AND I PARTICULARLY LIKE THE
TRANSITION THROUGH THE OVERNIGHT HOURS. THERE WILL BE A ZONE ACROSS
THE FORECAST AREA WHERE THE TOP DOWN METHOD AND FORECAST SOUNDINGS
SHOW THAT FREEZING RAIN COULD BE HAPPEN. RIGHT NOW, I WAS
CONSERVATIVE ON ICE ACCUMULATION AMOUNTS BUT IF THIS ZR AREA WERE TO
EXPAND WITH ELEVATED SHOWERS/CONVECTION ON TOP OF A SHALLOW COLD AIR
MASS...TREACHEROUS COMMUTING CONDITIONS WILL CERTAINLY BE A
POSSIBILITY. IT IS TOO EARLY TO MENTION A WINTER STORM WATCH, BUT AN
ICE STORM WARNING CANNOT BE COMPLETELY DISMISSED AT THIS POINT BASED
OFF 00Z DATA THAT WAS ANALYZED.
THURSDAY:
FOR THURSDAY, THE COUNTY WARNING AREA WILL CONTINUE TO BE IN THE
TRANSITION ZONE FOR PRECIPITATION TYPES. SNOW LOOKS LIKELY ACROSS MY
NORTHWEST COUNTIES WHERE RAIN LOOKS LIKELY ACROSS SOUTH CENTRAL
KANSAS. THE ECMWF IS MORE AGGRESSIVE WITH COLD AIR ADVECTION THROUGH
THE 850-700 HPA LAYER COMPARED TO THE NAM WHICH WANTS TO KEEP THE
WARM NOSE LINGERING AROUND, PARTICULARLY ACROSS SOUTH CENTRAL
KANSAS. AS MENTIONED BEFORE, WENT AHEAD AND USED THE NAM THERMO
FIELDS FOR PRECIPITATION TYPES ALTHOUGH THE ECMWF COULD BE MORE
CORRECT IN CONTINUING TO DRIVE THE COLD AIR SOUTHWARD THROUGH THE
DAY. ALL THESE DETAILS WILL BE HAMMERED OUT AS THE EVENT APPROACHES.
FRIDAY AND BEYOND:
DUE TO TIME CONSTRAINTS, DID NOT DEVIATE FROM THE ALLBLEND APPROACH.
THERE IS TOO MUCH UNCERTAINTY IN WHAT WILL HAPPEN WITH THE UPPER
LEVEL WAVE. THE ECMWF/GEM KEEPS THE WAVE CLOSER TO OUR AREA WHICH
WOULD PROVIDE THE REGION WITH A CHANCE OF SHOWERS AND SNOW SHOWERS.
THE GFS IS VERY PROGRESSIVE BUT AS MENTIONED ABOVE WAS DISCOUNTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 456 AM CST TUE MAR 6 2012
VFR CIGS WILL PREVAIL THROUGH THE TAF PERIOD. SOME HIGH LEVEL
CIRRIFORM CLOUDS ARE LIKELY TODAY SPREADING IN DOWNSTREAM OF
AN UPPER LEVEL DISTURBANCE LOCATED ACROSS THE DESERT SOUTHWEST.
OTHERWISE, BREEZY S/SW WINDS AROUND 20 KT ARE EXPECTED TO PEAK
THROUGH THIS AFTERNOON IN ASSOCIATION WITH ADIABATIC MIXING
AND LEE TROUGHING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 80 47 66 27 / 0 10 30 60
GCK 80 44 55 27 / 0 10 20 60
EHA 81 44 59 24 / 0 0 20 60
LBL 81 46 65 27 / 0 10 20 60
HYS 79 47 55 27 / 0 10 40 60
P28 75 52 69 34 / 0 20 70 80
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON CST /11 AM MST/ TODAY TO 7 PM CST /6
PM MST/ THIS EVENING FOR KSZ030-031-043>046-061>065-074>078-
084>087.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM....SUGDEN
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
404 AM CST TUE MAR 6 2012
...UPDATED SHORT TERM AND LONG TERM SECTIONS...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 359 AM CST TUE MAR 6 2012
SYNOPSIS:
WATER VAPOR LOOP AND LAST NIGHT`S RAOB ANALYSIS CONFIRMED THE
DEVELOPMENT OF SIGNIFICANT MID LEVEL TROUGH OVER THE PACIFIC
NORTHWEST REGION. 12-HR 500MB HEIGHT FALLS OF 130-170 METERS WERE
OBSERVED OVER WESTERN OREGON AND WASHINGTON. THE BASE OF THIS
TROUGH WAS CONTINUING TO DIG SOUTHEAST INTO NORTHERN CALIFORNIA AS
OF 09Z THIS MORNING. STRONG WEST-SOUTHWESTERLY MID LEVEL FLOW WAS
OCCURRING EAST OF THIS ACROSS THE GREAT BASIN REGION INTO THE
ROCKIES. THIS WAS RESULTING IN A LARGE AREA OF LOWER TROPOSPHERIC
WARMING WITH LOWER ELEVATION STATIONS ACROSS THE GREAT BASIN/ROCKIES
SEEING 850MB TEMPS IN THE MID TO UPPER TEENS. 700MB TEMPERATURES
WERE +4 TO +5C ACROSS ARIZONA AND NEW MEXICO. THE FRONT SEPARATING
THE COLD, POLAR AIRMASS FROM THE WARM INTERMOUNTAIN WEST AIRMASS WAS
POSITIONED FROM SOUTHWESTERN ALBERTA...EAST-SOUTHEASTWARD ALONG THE
CANADA-US BORDER TO A WEAK CYCLONIC CENTER AT 850MB NEAR THE
MANITOBA BORDER WITH MINNESOTA AND NORTH DAKOTA. STRONG SOUTHERLY
FLOW WAS NOTED ACROSS THE SOUTHERN PLAINS BETWEEN THE LEESIDE TROUGH
AND A GULF OF MEXICO HIGH.
TODAY:
THE VERY WARM AND DRY LOWER TROPOSPHERIC DOWNSLOPE AIRMASS WILL
YIELD ANOTHER UNSEASONABLY WARM DAY ACROSS SOUTHWEST KANSAS. GIVEN
THE RESULTS OF YESTERDAY AND AN EVEN WARMER THERMODYNAMIC
ENVIRONMENT TODAY...THERE IS MUCH MORE CONFIDENCE IN HIGHS TODAY
REACHING 80 DEGREES OVER A GOOD CHUNK OF SOUTHWEST KANSAS...AND HAVE
INCREASED THE MAXT GRID AS A RESULT. THE HRRR AND RUC MODELS WERE
USED AS THE PRIMARY GUIDANCE IN THE DEWPOINT/RH FORECAST FOR FIRE
WEATHER CONCERNS. DEWPOINTS WILL BE VERY LOW ACROSS THE
NORTHWESTERN 2/3RDS OF THE FORECAST AREA...IN THE 14 TO 20F
RANGE...AS TEMPERATURES RISE INTO THE UPPER 70S/NEAR 80. THIS WILL
RESULT IN RELATIVE HUMIDITY DOWN INTO THE 10 TO 15 PERCENT RANGE.
THE MAIN QUESTION REGARDING SIGNIFICANCE OF THE CRITICAL FIRE
WEATHER THREAT WILL BE WIND SPEED. HIGH RESOLUTION MODELS HAVE
TRENDED DOWNWARD IN THE WIND SPEED ACROSS THE VERY LOW RH AREAS FOR
THIS AFTERNOON...AND IT APPEARS THAT WIND SPEEDS WILL NOW BE RATHER
MARGINAL FOR CRITICAL FIRE WX. THE LATEST FORECAST WILL REFLECT 15
TO 20 MPH WINDS FOR MOST OF THE DAY...WITH 20 TO 25 MPH FOR ONLY A
COUPLE HOURS PROBABLY BY LATE AFTERNOON. GUSTS ARE STILL
ANTICIPATED TO BE 25 TO 30 MPH. FARTHER EAST WHERE THE MSLP
GRADIENT WILL BE TIGHTER...WINDS WILL BE FAIRLY STRONG AND APPROACH
WIND ADVISORY CATEGORY. HAVE DECIDED TO NOT ISSUE A WIND ADVISORY
IN THE SOUTH CENTRAL KANSAS COUNTIES GIVEN THE UNCERTAINTY IN DEEP
MIXING...BUT THE REALLY DEEP MIXING MAY NOT REALLY MATTER MUCH AND
WIND ADVISORY LEVEL WINDS (SUSTAINED 30 MPH) MAY STILL BE REACHED
ACROSS PRATT-COMANCHE-BARBER COUNTIES.
TONIGHT:
AS THE UPPER TROUGH CONTINUES TO DIG SOUTHEAST LATE TODAY AND
TONIGHT...THE FRONT (MENTIONED IN THE SYNOPSIS PARAGRAPH) WILL BEGIN
ITS EQUATORWARD PUSH. THE FRONT IS EXPECTED TO REACH FAR NORTHWEST
KANSAS AROUND 09Z TONIGHT. AHEAD OF THE FRONT IN SOUTHWEST
KANSAS...WIND SPEEDS WILL STAY FAIRLY STRONG BY NOCTURNAL STANDARDS
WITH SPEEDS AVERAGING 20 TO 30 MPH THROUGH MOST OF THE
NIGHT...ESPECIALLY THE SOUTHEAST HALF OF THE FORECAST AREA. THIS
WILL KEEP TEMPERATURES ABNORMALLY WARM THROUGH THE NIGHT WITH 06-12Z
TEMPERATURES IN THE LOWER 50S FOR A GOOD PORTION OF THE FORECAST
AREA. LOW LEVEL MOISTURE WILL ALSO BEGIN TO MOVE INTO THE
SOUTHEASTERN COUNTIES WITH DEWPOINT TEMPERATURES RISING INTO THE
UPPER 40S TO NEAR 50 (PARTICULARLY ACROSS BARBER COUNTY). THE
DEVELOPMENT OF LOW STRATUS WILL HAVE TO BE WATCHED...BUT AT THIS
TIME THE MAJORITY OF INITIAL LOW LEVEL CLOUD COVER TOWARD DAYBREAK
WEDNESDAY WILL BE ACROSS OKLAHOMA AND AREAS OF SOUTH CENTRAL KANSAS
JUST EAST OF BARBER COUNTY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 359 AM CST TUE MAR 6 2012
THE EXTENDED PERIOD BEGINS 12Z WEDNESDAY. LOTS OF WEATHER TO
CONSIDER, HOWEVER, THIS AFD SECTION WILL BE SLIGHTLY ABBREVIATED DUE
TO MOST OF THE TIME WAS SPENT ON THE GRIDS MAKING NUMEROUS
MODIFICATIONS. OVERALL, THE EXTENDED PERIOD RELIED HEAVILY ON THE
00Z ECMWF FOR THE SYNOPTIC PATTERN AND USED 00Z NAM FOR
THERMODYNAMICS. THE 00Z GFS WAS COMPLETELY DISMISSED AS IT IS A
CLEAR OUTLIER COMPARED TO THE ECMWF/NAM/GEM/UKMET.
WEDNESDAY:
ON WEDNESDAY, A SIGNIFICANT COLD FRONT WILL BE TRAVERSING ACROSS THE
REGION. HAVE ADOPTED A NON DIURNAL TEMPERATURE CURVE WITH A FIRST
GUESS FROM THE NAM AS PEAK HEATING WILL OCCUR NEAR THE NORMAL
AFTERNOON HOURS TOWARDS MEDICINE LODGE, HOWEVER AT SCOTT CITY TO
HAYS, MAX TEMPERATURES WILL BE REACHED EARLY AND THEN FALL LIKE A
ROCK AS THE FRONT MOVES THROUGH.
MOST OF THE DAY WEDNESDAY SHOULD REMAIN DRY, EXPECT ACROSS SOUTH
CENTRAL KANSAS WHERE WARM AIR ADVECTION AND ISENTROPIC LIFT COULD
PROVIDE THIS REGION WITH DRIZZLE. BY WEDNESDAY EVENING INTO THURSDAY
MORNING, A VORTMAX WILL SLIDE ACROSS THE REGION WITH SIGNIFICANT
HEIGHT FALLS AND RELATED AGEOSTROPHIC MOTIONS (DYNAMIC LIFT)
SPREADING ACROSS SOUTHWEST KANSAS. THIS DYNAMIC PROCESS WILL BE
ENOUGH TO CAUSE RAIN AND ISOLATED THUNDERSTORMS ACROSS SOUTH CENTRAL
KANSAS. ECMWF CAPE IS NOT PARTICULARLY IMPRESSIVE, HOWEVER, MID
LEVEL LAPSE RATES WILL CONTINUE TO STEEPEN SO THINK THERE WILL BE
ENOUGH INSTABILITY IN THE LOW TO MIDDLE PORTION OF THE ATMOSPHERE TO
PRODUCE SOME LIGHTNING. SEVERE WEATHER IS NOT ANTICIPATED AS ANY
CONVECTION WILL LIKE PEAK OVERNIGHT WITH SURFACE BASE INSTABILITY IS
AT A MINIMUM. PLUS, THE CONVECTION WILL BE ELEVATED. PERHAPS SOME
MARGINAL HAIL COULD OCCUR AT MEDICINE LODGE GIVEN THE AFOREMENTIONED
STEEP LAPSE RATES BUT IT IS TOO EARLY TO TELL.
MEANWHILE, THROUGH THE OVERNIGHT WEDNESDAY AND INTO THURSDAY,
SIGNIFICANT COLD AIR ADVECTION WILL BE OCCURRING ON THE BACKSIDE OF
OF 850-700 HPA TROUGH. RIGHT NOW, I HAVE EMPLOYED THE PROBABILITY OF
WEATHER TYPE TOOL FROM THE ESTF SMART TOOL REPOSITORY AND HAVE USED
THE NAM FOR A THERMODYNAMIC BACKGROUND. WOULD PREFER NOT TO USE
THIS MESOSCALE MODEL AT THIS TIME RANGE, HOWEVER, THE ECMWF HAS LOW
RESOLUTION IN THE VERTICAL AND CANNOT BE USED TO DETERMINE
PRECIPITATION TYPE. THE POWT ACTUALLY PRODUCED FAIRLY REASONABLE
LOOKING PRECIPITATION TYPE GRIDS AND I PARTICULARLY LIKE THE
TRANSITION THROUGH THE OVERNIGHT HOURS. THERE WILL BE A ZONE ACROSS
THE FORECAST AREA WHERE THE TOP DOWN METHOD AND FORECAST SOUNDINGS
SHOW THAT FREEZING RAIN COULD BE HAPPEN. RIGHT NOW, I WAS
CONSERVATIVE ON ICE ACCUMULATION AMOUNTS BUT IF THIS ZR AREA WERE TO
EXPAND WITH ELEVATED SHOWERS/CONVECTION ON TOP OF A SHALLOW COLD AIR
MASS...TREACHEROUS COMMUTING CONDITIONS WILL CERTAINLY BE A
POSSIBILITY. IT IS TOO EARLY TO MENTION A WINTER STORM WATCH, BUT AN
ICE STORM WARNING CANNOT BE COMPLETELY DISMISSED AT THIS POINT BASED
OFF 00Z DATA THAT WAS ANALYZED.
THURSDAY:
FOR THURSDAY, THE COUNTY WARNING AREA WILL CONTINUE TO BE IN THE
TRANSITION ZONE FOR PRECIPITATION TYPES. SNOW LOOKS LIKELY ACROSS MY
NORTHWEST COUNTIES WHERE RAIN LOOKS LIKELY ACROSS SOUTH CENTRAL
KANSAS. THE ECMWF IS MORE AGGRESSIVE WITH COLD AIR ADVECTION THROUGH
THE 850-700 HPA LAYER COMPARED TO THE NAM WHICH WANTS TO KEEP THE
WARM NOSE LINGERING AROUND, PARTICULARLY ACROSS SOUTH CENTRAL
KANSAS. AS MENTIONED BEFORE, WENT AHEAD AND USED THE NAM THERMO
FIELDS FOR PRECIPITATION TYPES ALTHOUGH THE ECMWF COULD BE MORE
CORRECT IN CONTINUING TO DRIVE THE COLD AIR SOUTHWARD THROUGH THE
DAY. ALL THESE DETAILS WILL BE HAMMERED OUT AS THE EVENT APPROACHES.
FRIDAY AND BEYOND:
DUE TO TIME CONSTRAINTS, DID NOT DEVIATE FROM THE ALLBLEND APPROACH.
THERE IS TOO MUCH UNCERTAINTY IN WHAT WILL HAPPEN WITH THE UPPER
LEVEL WAVE. THE ECMWF/GEM KEEPS THE WAVE CLOSER TO OUR AREA WHICH
WOULD PROVIDE THE REGION WITH A CHANCE OF SHOWERS AND SNOW SHOWERS.
THE GFS IS VERY PROGRESSIVE BUT AS MENTIONED ABOVE WAS DISCOUNTED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1132 PM CST MON MAR 5 2012
LEE TROUGHING WILL INCREASE ON TUESDAY AS AN UPPER LEVEL STORM
SYSTEM DEVELOPS ACROSS THE WESTERN UNITED STATES. WINDS WILL
INCREASE FROM THE SOUTH AT 20 TO 25 KTS BY 18-20Z. BY 03Z,
A 65KT LOW LEVEL JET WILL DEVELOP AT DDC/GCK/HYS. LOW-LEVEL WIND
SHEAR COULD BE A CONCERN, BUT CONFIDENCE IS NOT HIGH ENOUGH TO
INCLUDE IN THE 06Z TAF.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 80 47 66 27 / 0 10 30 60
GCK 80 44 55 27 / 0 10 20 60
EHA 81 44 59 24 / 0 0 20 60
LBL 81 46 65 27 / 0 10 20 60
HYS 79 47 55 27 / 0 10 40 60
P28 75 52 69 34 / 0 20 70 80
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON CST /11 AM MST/ TODAY TO 7 PM CST /6
PM MST/ THIS EVENING FOR KSZ030-031-043>046-061>065-074>078-
084>087.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM....SUGDEN
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1010 PM MST MON MAR 5 2012
.UPDATE...
ISSUED AT 922 PM MST MON MAR 5 2012
TONIGHT THROUGH TUESDAY NIGHT...CIRRUS WILL MOVE ACROSS THE AREA
TUESDAY AND TUESDAY NIGHT FROM THE SOUTHWEST AHEAD OF AN
APPROACHING AND DEVELOPING UPPER LOW THAT BY 12Z WEDNESDAY WILL BE
NEAR SOUTHWEST UTAH.
HIGH TEMPERATURES TUESDAY MID 70S TO LOW 80S PER GFS/NAM/UKMET 850
TEMPS WHICH ARE 2-5 DEGREES F WARMER THAN THIS AFTERNOONS
OBSERVED 850 TEMPS. RECORDS IN MCCOOK AND COLBY SHOULD BE TIED OR
BROKEN. WINDS WILL BECOME S/SW AND INCREASE INTO THE BREEZY TO
WINDY CATEGORY TUESDAY AFTERNOON DECREASING AFTER DARK.
RH VALUES TUESDAY AFTERNOON WILL DROP DOWN INTO THE 10 PERCENT
RANGE...POSSIBLY LOWER IN SPOTS. RED FLAG WARNING WAS ISSUED
EARLIER THIS AFTERNOON.
COLD FRONT TO MOVE IN BEFORE SUNRISE WEDNESDAY MORNING BRINGING
MUCH COLDER TEMPERATURES TO THE AREA FOR THE AFTERNOON HOURS.
UPDATE ISSUED AT 515 PM MST MON MAR 5 2012
ALLOWED RED FLAG WARNING AND WIND ADVISORY TO EXPIRE ON TIME. HAVE
UPGRADED FIRE WEATHER WATCH TUESDAY TO A RED FLAG WARNING AND
STARTED IT AN HOUR EARLIER PER CURRENT GRID RH VALUES AT OR BELOW
20 PERCENT FOR MUCH OF THE AREA. NO OTHER CHANGES MADE AT PRESENT
TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 214 PM MST MON MAR 5 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW WESTERLY FLOW
ACROSS THE INTER-MOUNTAIN WEST AND CENTRAL HIGH PLAINS. AT THE
SURFACE A LEE TROUGH HAS SHIFTED EAST TO BE NEAR THE COLORADO/KANSAS
STATE LINE.
THE TIGHTEST SURFACE GRADIENT REMAINS ALONG THE SE BORDER OF THE
CWA...WHERE THE WIND ADVISORY IS STILL IN EFFECT. WINDS HAVE JUST
STARTED TO REACH ADVISORY CRITERIA AT A FEW LOCATIONS EARLY THIS
AFTERNOON. WINDS WILL BEGIN TO DECREASE AS DAYTIME MIXING COMES TO
AN END. LOCATIONS CLOSER TO THE TROUGH AXIS MAY SEE WINDS DIMINISH
SOONER. FOR NOW THE WIND ADVISORY AND RED FLAG WARNING WILL BE
ALLOWED TO CONTINUE THROUGH 00Z...THOUGH WESTERN COUNTIES MAY BE
ALLOWED TO END EARLIER.
OVERNIGHT LOWS ARE TRICKY TONIGHT WITH WINDS AROUND 10 MPH POSSIBLE
EAST AND WEST OF SURFACE TROUGH...WITH EXACT LOCATION OF TROUGH AXIS
STILL IN QUESTION. IN ADDITION TO WINDS POSSIBLY ALLOWING FOR BETTER
OVERNIGHT MIXING...WAA WILL CONTINUE THROUGH THE NIGHT WITH H85
TEMPS 14-17C. CURRENT FORECAST CALLS FOR LOW TO MID 30S AND UPPER
30S IN THE EAST NEAR HILL CITY. THIS STILL MAY BE TOO COOL
CONSIDERING THE AIRMASS ALOFT.
NEAR RECORD HIGHS ARE STILL FORECAST FOR TUESDAY WITH SW FLOW AND A
VERY WARM AIRMASS IN PLACE ACROSS THE CWA. WITH AFTERNOON
TEMPERATURES TODAY REACHING THE MID 70S AT WESTERN LOCATIONS...THERE
SHOULD BE NO PROBLEMS REACHING THE UPPER 70S ON TUESDAY WHEN H85
TEMPS ARE FORECAST TO BE ABOUT 5C WARMER THAN TODAY. MANY LOCATIONS
WILL PROBABLY REACH 80F. RED FLAG CONDITIONS WILL ALSO BE POSSIBLE
TUESDAY WITH GUSTY WINDS VERY LOW RH VALUES EXPECTED ACROSS THE
AREA. A FIRE WEATHER WATCH REMAINS IN EFFECT FOR THE ENTIRE CWA
TUESDAY AFTERNOON AND EVENING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 214 PM MST MON MAR 5 2012
TUESDAY NIGHT AND WEDNESDAY A TROUGH OF DIGS INTO THE WESTERN
UNITED STATES AND FORMS A CLOSED LOW IN THE VICINITY OF THE
4-CORNERS REGION. CLOUDS WILL BEGIN TO INCREASE AHEAD OF THIS
SYSTEM AND THE SURFACE LOW PRESSURE AREA IS SEEMINGLY SPLIT INTO
TWO PARTS...WITH THE LEADING PORTION DEEPENING IN THE LEE OF THE
ROCKIES AND MOVING SOUTHWARD INTO THE CENTRAL HIGH PLAINS EARLY
WEDNESDAY MORNING AND THE TRAILING PORTION DEEPENING IN CLOSER
PROXIMITY TO THE UPPER LOW CENTER NEAR THE 4-CORNERS AREA. A COLD
FRONT ASSOCIATED WITH THE LEAD LOW PUSHES THROUGH THE FORECAST
AREA DURING THE DAY ON WEDNESDAY AND KEEPS HIGH TEMPERATURES 30
DEGREES COOLER OR MORE FROM TUESDAY/S HIGHS. VERY LITTLE IF ANY
PRECIPITATION IS EXPECTED WITH THIS FRONT AS IT SWEEPS THROUGH THE
REGION AS THE AIRMASS STILL REMAINS RELATIVELY DRY ALOFT AND THE
MAIN DYNAMICS WITH THE UPPER LOW CENTER ARE STILL OFF TO THE WEST.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT WILL BRING THE POSSIBILITY
OF A WINTRY MIX OF PRECIPITATION AS THE NORTHERN BRANCH OF THE
UPPER PATTERN SWEEPS A TROUGH ACROSS THE NORTHERN PLAINS AND THE
UPPER LOW NEAR THE 4-CORNERS REGION CUTS OFF AND DRIFTS SLOWLY
OVER NEW MEXICO. THE SURFACE AREA OF LOWER PRESSURE CONSOLIDATES
INTO A SINGLE LOW IN THE VICINITY OF FAR WESTERN TEXAS ON THURSDAY
AND BEGINS TO ELONGATE ALONG THE SURFACE FRONTAL BOUNDARY
STRETCHING FROM WESTERN TEXAS INTO THE MID-MISSISSIPPI VALLEY
REGION. THE BEST CHANCES OF PRECIPITATION WILL BE ALONG THIS
FRONTAL BOUNDARY...WITH DIMINISHING CHANCES THE FURTHER NORTH ONE
TRAVELS AWAY FROM THE BOUNDARY. HAVE PLACED A MIX OF MAINLY LIGHT
RAIN AND SNOW ACROSS THE FORECAST AREA WITH GREATER PRECIPITATION
ACCUMULATIONS ACROSS THE SOUTHERN AREAS.
THE CUT OFF UPPER LOW LINGERS OVER NEW MEXICO FRIDAY AND FRIDAY
NIGHT AND THEN BEGINS TO LIFT OUT ACROSS THE CENTRAL AND SOUTHERN
PLAINS ON SATURDAY THROUGH SUNDAY NIGHT. MODEL SOLUTIONS OFFER A
VARIETY OF SOLUTIONS OF NOW AND WHEN THE UPPER LOW EVENTUALLY
TRACKS EAST OF THE ROCKIES...SO CONFIDENCE IN ANY ONE SOLUTION IS
MINIMAL AT THIS TIME. HAVE KEPT A SLIGHT CHANCE OF RAIN AND RAIN
AND SNOW ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA DURING THIS TIME WITH A GENERAL RETURN OF TEMPERATURES TO
NEAR NORMAL.
WITH A SHORT WAVE RIDGE MOVING OVER THE AREA IN THE WAKE OF THE
UPPER LOW LIFTING THROUGH...HAVE KEPT THE EARLY PART OF NEXT WEEK
DRY WITH SLIGHTLY WARMER CONDITIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1004 PM MST MON MAR 5 2012
VFR CONDITIONS FOR BOTH KGLD AND KMCK. WEST WINDS AROUND 11KTS AT
PRESENT TIME WILL SHIFT TO THE SOUTH/SOUTHWEST AND INCREASE INTO
THE 15-20G30KT RANGE BY LATE TUESDAY MORNING/EARLY AFTERNOON AHEAD
OF AN APPROACHING COLD FRONT...DECREASING SHORTLY AFTER SUNSET JUST A
FEW CIRRUS CLOUDS EXPECTED...MAINLY TOWARD TUESDAY MORNING.
&&
.FIRE WEATHER...
ISSUED AT 515 PM MST MON MAR 5 2012
RED FLAG WARNING IN EFFECT FOR THE ENTIRE TRI-STATE AREA. RH
VALUES AS LOW AS 8 PERCENT AND SOUTHWEST WINDS GUSTING 35 MPH WILL
PRODUCE CRITICAL FIRE WEATHER CONDITIONS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING FROM 10 AM TO 7 PM MST TUESDAY FOR COZ252>254.
KS...RED FLAG WARNING FROM 10 AM MST /11 AM CST/ TO 7 PM MST /8 PM
CST/ TUESDAY FOR KSZ001>004-013>016-027>029-041-042.
NE...RED FLAG WARNING FROM 10 AM MST /11 AM CST/ TO 7 PM MST /8 PM
CST/ TUESDAY FOR NEZ079>081.
&&
$$
UPDATE...007
SHORT TERM...DR
LONG TERM....LOCKHART
AVIATION...007
AREA FORECAST DISCUSSION
NWS GOODLAND KS
930 PM MST MON MAR 5 2012
.UPDATE...
ISSUED AT 922 PM MST MON MAR 5 2012
TONIGHT THROUGH TUESDAY NIGHT...CIRRUS WILL MOVE ACROSS THE AREA
TUESDAY AND TUESDAY NIGHT FROM THE SOUTHWEST AHEAD OF AN
APPROACHING AND DEVELOPING UPPER LOW THAT BY 12Z WEDNESDAY WILL BE
NEAR SOUTHWEST UTAH.
HIGH TEMPERATURES TUESDAY MID 70S TO LOW 80S PER GFS/NAM/UKMET 850
TEMPS WHICH ARE 2-5 DEGREES F WARMER THAN THIS AFTERNOONS
OBSERVED 850 TEMPS. RECORDS IN MCCOOK AND COLBY SHOULD BE TIED OR
BROKEN. WINDS WILL BECOME S/SW AND INCREASE INTO THE BREEZY TO
WINDY CATEGORY TUESDAY AFTERNOON DECREASING AFTER DARK.
RH VALUES TUESDAY AFTERNOON WILL DROP DOWN INTO THE 10 PERCENT
RANGE...POSSIBLY LOWER IN SPOTS. RED FLAG WARNING WAS ISSUED
EARLIER THIS AFTERNOON.
COLD FRONT TO MOVE IN BEFORE SUNRISE WEDNESDAY MORNING BRINGING
MUCH COLDER TEMPERATURES TO THE AREA FOR THE AFTERNOON HOURS.
UPDATE ISSUED AT 515 PM MST MON MAR 5 2012
ALLOWED RED FLAG WARNING AND WIND ADVISORY TO EXPIRE ON TIME. HAVE
UPGRADED FIRE WEATHER WATCH TUESDAY TO A RED FLAG WARNING AND
STARTED IT AN HOUR EARLIER PER CURRENT GRID RH VALUES AT OR BELOW
20 PERCENT FOR MUCH OF THE AREA. NO OTHER CHANGES MADE AT PRESENT
TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 214 PM MST MON MAR 5 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW WESTERLY FLOW
ACROSS THE INTER-MOUNTAIN WEST AND CENTRAL HIGH PLAINS. AT THE
SURFACE A LEE TROUGH HAS SHIFTED EAST TO BE NEAR THE COLORADO/KANSAS
STATE LINE.
THE TIGHTEST SURFACE GRADIENT REMAINS ALONG THE SE BORDER OF THE
CWA...WHERE THE WIND ADVISORY IS STILL IN EFFECT. WINDS HAVE JUST
STARTED TO REACH ADVISORY CRITERIA AT A FEW LOCATIONS EARLY THIS
AFTERNOON. WINDS WILL BEGIN TO DECREASE AS DAYTIME MIXING COMES TO
AN END. LOCATIONS CLOSER TO THE TROUGH AXIS MAY SEE WINDS DIMINISH
SOONER. FOR NOW THE WIND ADVISORY AND RED FLAG WARNING WILL BE
ALLOWED TO CONTINUE THROUGH 00Z...THOUGH WESTERN COUNTIES MAY BE
ALLOWED TO END EARLIER.
OVERNIGHT LOWS ARE TRICKY TONIGHT WITH WINDS AROUND 10 MPH POSSIBLE
EAST AND WEST OF SURFACE TROUGH...WITH EXACT LOCATION OF TROUGH AXIS
STILL IN QUESTION. IN ADDITION TO WINDS POSSIBLY ALLOWING FOR BETTER
OVERNIGHT MIXING...WAA WILL CONTINUE THROUGH THE NIGHT WITH H85
TEMPS 14-17C. CURRENT FORECAST CALLS FOR LOW TO MID 30S AND UPPER
30S IN THE EAST NEAR HILL CITY. THIS STILL MAY BE TOO COOL
CONSIDERING THE AIRMASS ALOFT.
NEAR RECORD HIGHS ARE STILL FORECAST FOR TUESDAY WITH SW FLOW AND A
VERY WARM AIRMASS IN PLACE ACROSS THE CWA. WITH AFTERNOON
TEMPERATURES TODAY REACHING THE MID 70S AT WESTERN LOCATIONS...THERE
SHOULD BE NO PROBLEMS REACHING THE UPPER 70S ON TUESDAY WHEN H85
TEMPS ARE FORECAST TO BE ABOUT 5C WARMER THAN TODAY. MANY LOCATIONS
WILL PROBABLY REACH 80F. RED FLAG CONDITIONS WILL ALSO BE POSSIBLE
TUESDAY WITH GUSTY WINDS VERY LOW RH VALUES EXPECTED ACROSS THE
AREA. A FIRE WEATHER WATCH REMAINS IN EFFECT FOR THE ENTIRE CWA
TUESDAY AFTERNOON AND EVENING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 214 PM MST MON MAR 5 2012
TUESDAY NIGHT AND WEDNESDAY A TROUGH OF DIGS INTO THE WESTERN
UNITED STATES AND FORMS A CLOSED LOW IN THE VICINITY OF THE
4-CORNERS REGION. CLOUDS WILL BEGIN TO INCREASE AHEAD OF THIS
SYSTEM AND THE SURFACE LOW PRESSURE AREA IS SEEMINGLY SPLIT INTO
TWO PARTS...WITH THE LEADING PORTION DEEPENING IN THE LEE OF THE
ROCKIES AND MOVING SOUTHWARD INTO THE CENTRAL HIGH PLAINS EARLY
WEDNESDAY MORNING AND THE TRAILING PORTION DEEPENING IN CLOSER
PROXIMITY TO THE UPPER LOW CENTER NEAR THE 4-CORNERS AREA. A COLD
FRONT ASSOCIATED WITH THE LEAD LOW PUSHES THROUGH THE FORECAST
AREA DURING THE DAY ON WEDNESDAY AND KEEPS HIGH TEMPERATURES 30
DEGREES COOLER OR MORE FROM TUESDAY/S HIGHS. VERY LITTLE IF ANY
PRECIPITATION IS EXPECTED WITH THIS FRONT AS IT SWEEPS THROUGH THE
REGION AS THE AIRMASS STILL REMAINS RELATIVELY DRY ALOFT AND THE
MAIN DYNAMICS WITH THE UPPER LOW CENTER ARE STILL OFF TO THE WEST.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT WILL BRING THE POSSIBILITY
OF A WINTRY MIX OF PRECIPITATION AS THE NORTHERN BRANCH OF THE
UPPER PATTERN SWEEPS A TROUGH ACROSS THE NORTHERN PLAINS AND THE
UPPER LOW NEAR THE 4-CORNERS REGION CUTS OFF AND DRIFTS SLOWLY
OVER NEW MEXICO. THE SURFACE AREA OF LOWER PRESSURE CONSOLIDATES
INTO A SINGLE LOW IN THE VICINITY OF FAR WESTERN TEXAS ON THURSDAY
AND BEGINS TO ELONGATE ALONG THE SURFACE FRONTAL BOUNDARY
STRETCHING FROM WESTERN TEXAS INTO THE MID-MISSISSIPPI VALLEY
REGION. THE BEST CHANCES OF PRECIPITATION WILL BE ALONG THIS
FRONTAL BOUNDARY...WITH DIMINISHING CHANCES THE FURTHER NORTH ONE
TRAVELS AWAY FROM THE BOUNDARY. HAVE PLACED A MIX OF MAINLY LIGHT
RAIN AND SNOW ACROSS THE FORECAST AREA WITH GREATER PRECIPITATION
ACCUMULATIONS ACROSS THE SOUTHERN AREAS.
THE CUT OFF UPPER LOW LINGERS OVER NEW MEXICO FRIDAY AND FRIDAY
NIGHT AND THEN BEGINS TO LIFT OUT ACROSS THE CENTRAL AND SOUTHERN
PLAINS ON SATURDAY THROUGH SUNDAY NIGHT. MODEL SOLUTIONS OFFER A
VARIETY OF SOLUTIONS OF NOW AND WHEN THE UPPER LOW EVENTUALLY
TRACKS EAST OF THE ROCKIES...SO CONFIDENCE IN ANY ONE SOLUTION IS
MINIMAL AT THIS TIME. HAVE KEPT A SLIGHT CHANCE OF RAIN AND RAIN
AND SNOW ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA DURING THIS TIME WITH A GENERAL RETURN OF TEMPERATURES TO
NEAR NORMAL.
WITH A SHORT WAVE RIDGE MOVING OVER THE AREA IN THE WAKE OF THE
UPPER LOW LIFTING THROUGH...HAVE KEPT THE EARLY PART OF NEXT WEEK
DRY WITH SLIGHTLY WARMER CONDITIONS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 515 PM MST MON MAR 5 2012
VFR CONDITIONS FOR BOTH KGLD AND KMCK. SOUTHWEST WINDS AT PRESENT
TIME WILL BECOME WESTERLY EARLY TONIGHT THEN SHIFT TO THE
SOUTH/SOUTHWEST AND INCREASE INTO THE 15-20G30KT RANGE BY LATE
TUESDAY MORNING/EARLY AFTERNOON AHEAD OF AN APPROACHING COLD
FRONT. JUST A FEW CIRRUS EXPECTED...MAINLY TOWARD MORNING.
&&
.FIRE WEATHER...
ISSUED AT 515 PM MST MON MAR 5 2012
RED FLAG WARNING IN EFFECT FOR THE ENTIRE TRI-STATE AREA. RH
VALUES AS LOW AS 8 PERCENT AND SOUTHWEST WINDS GUSTING 35 MPH WILL
PRODUCE CRITICAL FIRE WEATHER CONDITIONS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING FROM 10 AM TO 7 PM MST TUESDAY FOR COZ252>254.
KS...RED FLAG WARNING FROM 10 AM MST /11 AM CST/ TO 7 PM MST /8 PM
CST/ TUESDAY FOR KSZ001>004-013>016-027>029-041-042.
NE...RED FLAG WARNING FROM 10 AM MST /11 AM CST/ TO 7 PM MST /8 PM
CST/ TUESDAY FOR NEZ079>081.
&&
$$
UPDATE...007
SHORT TERM...DR
LONG TERM....LOCKHART
AVIATION...007
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
406 PM EST TUE MAR 6 2012
.SYNOPSIS...
ISSUED AT 405 PM EST TUE MAR 6 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF MOVING INTO THE
ROCKIES WITH A BROAD DOWNSTREAM RIDGE EXPANDING FROM THE CNTRL TO
ERN CONUS. MAIN PORTION OF THIS TROF WILL SHIFT ACROSS THE NRN
CONUS/GREAT LAKES AND NEW ENGLAND OVER THE NEXT SEVERAL DAYS WHILE
ENERGY IN THE SRN PORTION OF THE TROF BREAKS OUT AND CLOSES OFF OVER
THE SW STATES. TROF WILL BRING A PERIOD OF PCPN WED THRU THU.
EVENTUALLY...THE SW LOW WILL EJECT OUT TO THE NE OVER THE
WEEKEND/EARLY NEXT WEEK. WHAT AFFECTS THE LOW WILL HAVE OVER THE
UPPER LAKES REMAINS TO BE SEEN.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 405 PM EST TUE MAR 6 2012
IN THE SHORT TERM...CONCERNS REVOLVE AROUND TEMP TRENDS...FOG
DEVELOPMENT AND THEN PCPN WED ASSOCIATED WITH COLD FRONT/TROF MOVING
INTO THE UPPER LAKES.
DWPTS ARE RISING INTO THE MID 30S TO LWR 40S AS FAR NE SE MN/SW WI
THIS AFTN WITH TRAJECTORIES BRINGING THAT MOISTURE INTO UPPER MI
DURING THE NIGHT AND WED MORNING. WITH THE LOW-LEVEL MOISTURE
ADVECTION OVER THE SNOW COVER...STRATUS/FOG SHOULD EVENTUALLY
DEVELOP TONIGHT. DENSE FOG MAY DEVELOP...ESPECIALLY OVER UPSLOPE
HIGHER TERRAIN LATE TONIGHT INTO WED. IF THERE WAS SOME ADDITIONAL
MOISTURE FROM RAIN/DRIZZLE...WOULD GO WITH MORE OF A DENSE FOG
WORDING. FOR NOW...GOING FCST OF AN INCREASE IN LOWER CLOUDS AND FOG
DEVELOPMENT...MAINLY LATER TONIGHT...LOOKS ON TRACK. TEMPS SHOULDN`T
FALL MUCH IF AT ALL UNDER MOISTURE ADVECTION AND FAIRLY TIGHT PRES
GRADIENT/STIRRING WINDS. MINS SHOULD BE IN THE MID 30S TO LWR 40S...
WARMEST IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR.
COLD FRONT IS STILL ON TRACK TO MOVE THRU THE AREA LATER WED
AFTN/EVENING AS SFC LOW MOVES ACROSS NORTHERN PORTIONS OF ONTARIO.
EVEN WITH CLOUDS/FOG (POSSIBLY DENSE) AHEAD OF THE FRONT...WARM
START TO THE DAY SHOULD ALLOW TEMPS TO RISE WELL INTO THE 40S AHEAD
OF THE FRONT WED. FCST SOUNDINGS FROM NAM/GFS INDICATE RAIN WILL BE
PTYPE. EXCEPTION WILL BE THE FAR W LATE IN THE DAY. SOUNDINGS THERE
INITIALLY SHOW COOLING WORKING IN BLO 850MB...THEN SHOW ALL OF THE
PROFILE NEAR OR BLO 0C LATE AFTN...RESULTING IN CHANGE TO SNOW...
WITH SLEET POSSIBLE AT LEAST BRIEFLY AS WELL. WITH SLOWER COOLING
NOTED BY GEM/UKMET...OPTED TO SLOW CHANGEOVER BY A FEW HRS. NOT
EXPECTING ANY SNOW/SLEET ACCUMULATION WED WITH TEMPS WELL INTO THE
30S THRU LATE AFTN OVER THE W. OTHERWISE...WITH ASSISTANCE OF RIGHT
ENTRANCE OF UPPER JET...EXPECT AN AREA OF -RA TO DEVELOP
(LIKELY/CATEGORICAL POPS)...MOSTLY ALONG/JUST BEHIND COLD FRONT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 405 PM EST TUE MAR 6 2012
COLD FRONT WILL BE STRETCHED FROM NE TO SW ACROSS THE CNTRL/ERN CWA
AT THE START OF THE PERIOD...WHILE THE UPPER TROUGH IS STARTING TO
PUSH INTO THE UPPER GREAT LKS. THIS FRONT WILL CONTINUE TO SLIDE SE
INTO NRN LOWER MI DURING THE EARLY OVERNIGHT HRS. PCPN DEVELOPING
ALONG THE FRONT TOMORROW AFTN WILL LARGELY BE FOCUSED OVER THE ERN
CWA AT THE START OF THE PERIOD. THIS SHOULD BE FALLING AS RAIN...DUE
TO THE ABUNDANT WAA FROM H925-800 LEADING TO TEMPS AT OR ABOVE 3C.
FARTHER W IN CNTRL AND WRN UPPER MI...LLVL COLD AIR SURGING IN
BEHIND THE FRONT WILL BRING IN A COLD LAYER FOR THE PCPN TO FALL
INTO. THE MAIN QUESTION IS HOW QUICKLY THAT COLD AIR WILL SURGE IN
BEHIND THE PCPN SHIFTING TO THE SE. MAY NOT BE ENOUGH COLD AIR TO
ALLOW SLEET TO OCCUR...BUT DID MENTION A SLIGHT CHANCE OF IT ON THE
BACK SIDE OF THE MAIN PCPN. IN ADDITION...SOME CONCERNS ON ICE
CRYSTAL PRESENCE IN THE CLOUDS ON THE BACK EDGE OF THE PCPN. EVEN AS
TEMPS START TO COOL BEHIND THE FRONT...THEY REALLY DON/T FALL MUCH
BELOW -5C UNTIL THE BULK OF THE PCPN HAS MOVED TO THE EAST. THINKING
IT WILL LARGELY BE A RAIN...THEN A QUICK PERIOD OF SLEET AND EITHER
END OR BE A SLIGHT DZ/FLURRIES.
THINK BEST CHANCES FOR SNOW WILL BE OVER THE W IN THE EVENING...AS
THE COLD AIR ALLOWS FOR LK ENHANCEMENT WITH H900-875 TEMPS FALLING
TO -8C. CLOUD DEPTH SHOULD BE LIMITED WITH THE INVERSION AROUND H850
OR 3KFT. THUS...WILL MAINLY BE FLURRIES OR LIGHT SNOW SHOWERS AND
LINGERED CHANCES/SLIGHTS OVER THE NW FAVORED LOCATIONS IN THE W
THROUGH THE EARLY OVERNIGHT HRS. DRY LLVL AIR WILL THEN QUICKLY WORK
IN OVERNIGHT...SO HAVE DIMINISHED THE LINGERING POPS QUICKLY FROM W
TO E NEAR LK SUPERIOR.
THERE IS SOME POTENTIAL FOR CLEARING OVER THE INTERIOR W LATE IN THE
NIGHT...WHICH COULD ALLOW TEMPS TO FALL BELOW GUIDANCE WITH PWAT
VALUES AROUND 55 PERCENT OF NORMAL. WINDS WILL BE DIMINISHING WITH
THE APPROACHING SFC RIDGE...BUT MAY NOT ARRIVE EARLY ENOUGH TO
MAXIMIZE THE RADIATIONAL COOLING. WILL HIGHLIGHT THE COLDEST VALUES
NEAR WATERSMEET WITH LOWS IN THE UPPER TEENS.
UPPER TROUGH WILL BE MOVING OVER THE UPPER GREAT LAKES THROUGH
THE DAY ON THURS...ALLOWING SFC LOW TO DEVELOP OVER SRN ONTARIO
THURS AFTN AND INTENSIFY AS IT MOVES SE ON THURS NIGHT. DRY AIR
ABOVE H850 BEHIND THE FRONT WILL BE PUSHING FROM NW TO SE ACROSS THE
AREA THURS MORN AHEAD OF SECONDARY TROUGH BRINGING DEEPER MOISTURE
AND COLDER AIR. THINK THIS WILL LEAD TO A PERIOD OF PARTLY CLOUDY
TO MOSTLY SUNNY SKY OVER MUCH OF THE CWA IN THE MORNING. THEN...AS
THE TROUGH MOVES INTO THE AREA AND BRINGS DEEPER MOISTURE AND
H850-700 Q-VECTOR CONV...HAVE INCREASED CLOUDS AND BRING
SLIGHT/CHANCES OF SNOW BACK IN THE AFTN NEAR LK SUPERIOR.
UPPER TROUGH WILL START TO PUSH E ON THURS NIGHT AND CONTINUE E ON
FRI...AS RIDGING STARTS TO MOVE OVER THE AREA AND SFC HIGH PUSHES
INTO THE WRN GREAT LKS. WITH SECONDARY COLD FRONT DROPPING SE
ACROSS LK SUPERIOR...EXPECT ADDITIONAL LLVL MOISTURE AND FALLING
H850 TEMPS TOWARDS -13C TO LEAD TO INCREASING LAKE
EFFECT/ENHANCEMENT FOR AREAS NEAR LK SUPERIOR. WITH THE STRONG NW
AND THEN NNW WINDS...EXPECT CLOUD COVER TO SPREAD ACROSS MUCH OF
THE AREA THURS NIGHT AND CONTINUE INTO FRI MORNING. WITH THE COLD
AIR SPILLING IN...EXPECT GUSTY WINDS AS H925 WINDS TO 35KTS OVER THE
NE HALF OF THE CWA TO MIX TO THE SFC AND PRODUCE 25-35KT GUSTS NEAR
LK SUPERIOR E OF MARQUETTE. OVERALL...DON/T EXPECT TOO MUCH SNOW
ACCUM AS THE PERIOD OF FAVORABLE CONDITIONS IT FAIRLY LIMITED ON
THURS NIGHT...BEFORE DRIER AIR ARRIVES AND LOWERING INVERSION
HEADING THROUGH THE DAY ON FRI. IN ADDITION...WITH THE INCREASING
H850 WAA ON FRI AFTN OVER THE WRN LK WILL ALSO AID TO END THE
LINGERING LES FROM W TO E THROUGH THE DAY FRI. ALL IN
ALL...THURS AND FRI LOOK TO BE A PERIOD OF NORMAL TO BELOW
NORMAL TEMPS ACROSS THE AREA AHEAD OF THE POTENTIAL WARM-UP FOR
THE WEEKEND INTO NEXT WEEK.
DAYS 4 THROUGH 7 /FRI NIGHT THROUGH TUESDAY/...
UPPER LOW SPINNING OVER THE FOUR CORNERS REGION ON FRI NIGHT WILL
BEGIN TO GET CAUGHT UP WITH THE FLOW AND DRIFT NNE.
MEANWHILE...NEARLY ZONAL FLOW NRN STREAM LOOKS TO BE SETUP OVER SRN
CANADA...KEEPING THE COLD AIR WELL N OF THE UPPER GREAT LKS.
12Z RUNS CONTINUE THE DIFFERENCES WITH THE TRACK OF THE
UPPER LOW. HPC PREFERS A CONSENSUS SOLN NOT INCLUDING THE
GFS...WHICH TRACKS THE LOW MUCH FASTER AND FARTHER SE. 12Z RUN IS
THE SAME AND REMAINS VERY CONSISTENT OVER THE LAST SEVERAL
RUNS...WHICH COULD LEAD SOME CREDIT TO THE THAT SOLN. ENS MEAN ON
ECMWF/GEM IS A LITTLE SLOWER THAN THE DETERMINISTIC RUN...BUT
FOLLOWS A SIMILAR TRACK. OVERALL CONSENSUS PULLS THE UPPER LOW
THROUGH THE GREAT LKS REGION SUN INTO MON. WILL CONTINUE TO MENTION
CHANCE POPS ACROSS THE AREA...WHICH SHOULD FALL AS RAIN DUE TO THE
WARM AIR ALREADY IN PLACE.
EXTENDED MODELS CONTINUE TO SHOW THE POTENTIAL FOR A BIG WARM UP
BEHIND THE UPPER LOW THAT MOVES THROUGH THE GREAT LKS. AMPLIFYING
AND NEARLY STATIONARY TROUGH OFF THE W COAST OF THE CONUS WILL LEAD
TO AMPLIFYING RIDGE OVER THE CANADIAN PRAIRIES. THIS WILL ALLOW SFC
HIGH TO BE STATIONED OVER THE ERN CONUS AND WITH THE MAIN LOWS
TRACKING WELL TO THE N THROUGH CANADA...EXPECT SRLY FLOW TO BE SETUP
OVER THE CWA. CONSENSUS OF THE MODELS GIVES VALUES IN THE 40S AND
NEAR 50 ALONG THE WI BORDER FOR HIGHS ON TUES. THIS IS USUALLY UNDER
DONE IN WELL ABOVE NORMAL SITUATIONS AND THE ECMWF /WHICH ALMOST
ALWAYS VERIFIES THE BEST IN THESE ABOVE NORMAL SITUATIONS/ HAS
VALUES ABOUT 7-10 DEGREES WARMER THAN THE CONSENSUS. THE TEMPS LOOK
TO GET EVEN WARMER HEADING INTO WED/THURS. ECMWF HAS TEMPS FOR
WED/THURS OF NEXT WEEK OVER THE W HALF IN THE 60S WITH COOLER TEMPS
NEAR LK MI WITH THE SSW FLOW. ECMWF EVEN ATTEMPTS TO TRY AN PUSH A
FEW 70S ALONG THE WI BORDER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1238 PM EST TUE MAR 6 2012
VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW INTO EARLY EVENING.
INCREASING LOW-LEVEL MOISTURE OVER SNOWPACK SHOULD RESULT IN LOW
CLOUDS/FOG DEVELOPING TONIGHT...WITH BEST CHC OF LOW MVFR/POSSIBLE
IFR CIG AT KSAW DUE TO UPSLOPE COMPONENT TO SOUTHERLY WIND.
DOWNSLOPE NATURE OF SOUTHERLY WIND AT KIWD/KCMX SHOULD HELP TO
MAINTAIN VFR CONDITIONS AT THOSE SITES. WITH FAIRLY STRONG WINDS
ABOVE LOW-LEVEL INVERSION...EXPECT LLWS TONIGHT. IFR CIGS ARE LIKELY
TO SETTLE IN AT ALL SITES WED MORNING AS LOW-LEVEL MOISTURE
CONTINUES TO INCREASE AHEAD OF APPROACHING COLD FRONT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EST TUE MAR 6 2012
SOUTHERLY WINDS OF 20-30KT OVER ERN LAKE SUPERIOR (LIGHTER OVER THE
W) AHEAD OF AN APPROACHING COLD FRONT WILL SLOWLY DIMINISH TONIGHT.
WINDS SHOULD MOSTLY DROP OFF BLO 20KT FOR MUCH OF WED AS THE COLD
FRONT ARRIVES. WITH THE PASSAGE OF COLD FRONT...NW WINDS WILL BE ON
THE INCREASE WED EVENING AND THEN THRU THU AS A FOLLOWING LOW PRES
CENTER PASSES SE ACROSS NRN ONTARIO. UNDER CAA/INCREASING OVERWATER
INSTABILITY...NW WINDS WILL INCREASE TO 20-30KT...ESPECIALLY THU/THU
NIGHT. GALES ARE A POSSIBILITY. WINDS WILL DIMINISH TO UNDER 20KT BY
LATE FRIDAY AFTN AS HIGH PRESSURE BUILDS INTO THE REGION. ON THE
BACKSIDE OF THE HIGH...SW WINDS WILL RAMP BACK UP TO 20-30KT SAT.
&&
.HYDROLOGY...
ISSUED AT 405 PM EST TUE MAR 6 2012
EVEN WITH THE WARM TEMPS OVER THE NEXT 24-36 HOURS...DON/T EXPECT
MUCH IF ANY MELTING TO OCCUR DUE TO THE UN-RIPE CONDITIONS OF THE
SNOW PACK. LOOKING AT NOHRSC CURRENT AND FUTURE SNOWPACK
TEMPERATURES...ONLY THE TOP AND MIDDLE LAYERS /TOP 2-10 INCHES
DEPENDING ON LOCATION/ OF THE SNOWPACK BECOME RIPE OVER THE SW HALF
OF THE CWA BY WED EVENING. THIS WILL LIKELY LEAD TO SOME
COMPACTION/MELTING OF THE TOP OF THE EXISTING SNOWPACK...BUT IT
SHOULD STILL RETAIN THE WATER AND KEEP MUCH OR ALL OF THE MOISTURE
IN THE SNOWPACK THROUGH WED EVENING.
WITH COOLER TEMPERATURES EXPECTED BEHIND THE COLD FRONT ON
WED...DON/T EXPECT ANY MELTING TO OCCUR WED NIGHT INTO SAT. WITH THE
WARMING TREND EXPECTED DURING THE WEEKEND AND INTO NEXT WEEK...WILL
NEED TO KEEP AN EYE ON A SLOWLY RIPENING SNOWPACK. THE POTENTIAL FOR
RAIN ON SUN/MON MAY ASSIST IN THIS RIPENING THROUGH THE FIRST PART
OF NEXT WEEK.
THE POTENTIAL FOR MELTING OF THE SNOWPACK COULD GREATLY INCREASE
HEADING INTO THE MIDDLE OF NEXT WEEK...AS OVERNIGHT LOWS AND TD
VALUES RISE ABOVE FREEZING. THE EXTENDED MODELS HAVE BEEN SHOWING
WELL ABOVE NORMAL TEMPERATURES /10 PLUS DEGREES/ FOR THE MIDDLE OF
NEXT WEEK. IF THE WARM TEMPS SHOWN ON THE ECMWF /HIGHS IN THE 60S
FOR WED AND THURS/ COME TO FRUITION...THE MELT MAY BE FAIRLY FAST
AND RUN OFF DIRECTLY INTO AREA RIVERS. THUS...WILL NEED TO KEEP AN
EYE ON AREA RIVERS AND STREAMS NEXT WEEK FOR THE POTENTIAL OF RISING
LEVELS DUE TO SNOWMELT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...ROLFSON
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS GLASGOW MT
950 AM MST TUE MAR 6 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
UPDATE...SPLITTING UPPER TROUGH CONTINUES TO PUSH THROUGH
NORTHEAST MONTANA. BAND OF LIGHT RAIN CURRENTLY LIES FROM
PLENTYWOOD THROUGH JORDAN AND CONTINUES TO SLOWLY DRIFT TO THE
SOUTH AND EAST. SURFACE COLD FRONT IS PUSHING IN BEHIND THIS
BAND...WITH NORTHWEST WINDS INCREASING AND TEMPERAUTRES FALLING
BEHIND THE FRONT. UPDATED TO ADJUST POPS CLOSER TO RADAR
OBSERVATIONS THIS MORNING...AND IN LINE WITH THE HRRR MODEL THIS
AFTERNOON WHICH IS CURRENTLY THE PERFORMER AMONG THE DIFFERENT
MODELS. PRECIP WILL HAVE ENDED BY LATE AFTERNOON/EARLY
EVENING...WITH COLDER TEMPERATURES EXPECTED TONIGHT. GILCHRIST
PREVIOUS DISCUSSION...UPPER SPLITTING TROUGH IS MOVING IN FROM
THE NORTHWEST AND AS MODELS HAVE BEEN SAYING OVER THE LAST SEVERAL
DAYS. THE UPPER TROUGH WILL SPLIT WITH MOST OF THE ENERGY
FOLLOWING THE SOUTHERN PART BECOMING A CLOSED CUT OFF SYSTEM OVER
THE FOUR CORNERS AREA. THE NORTHERN PART HAS ALREADY COLLECTED THE
QUASI STATIONARY FRONT ACROSS SOUTHERN CANADA AND WILL PUSH IT
SOUTH AND EAST INTO EASTERN MONTANA AS WE GO THROUGH THE DAY. IT
LOOKS LIKE THE REALLY BIG DROP IN TEMPERATURES WILL OCCUR THIS
AFTERNOON AS THE CONTINENTAL POLAR AIR MASS MOVES IN FROM THE
NORTHWEST. MOST HIGHS WILL OCCUR EARLY TUESDAY WITH MODERATELY
STRONG COLD AIR ADVECTION DROPPING 850 MB TEMPS TO AS LOW AS -13C
IN OUR N BY 5 PM TUESDAY. WINDS AT 850 MB ARE AROUND 30 KNOTS
BEHIND THE FRONT IN THE AFTERNOON SO EXPECT A MODERATE NORTHWEST
WIND MAKING TEMPERATURES FEEL MUCH COLDER AS THESE WIND MIX TO THE
SURFACE.
THE ONE THING ABOUT THIS SYSTEM IS THE MODELS ARE SLIGHTLY OFF ON
PLACEMENT OF THE SURFACE FRONT AND SURFACE LOW THIS MORNING. THE
LATEST 09Z RUC IS IN BETTER AGREEMENT WITH SURFACE OBSERVATIONS
AND THE FRONT IS MUCH FARTHER SOUTH THEN THE 00Z MODELS WERE
INDICATING. THIS IS INTERESTING SINCE THE LAST THREE CLIPPER
SYSTEMS WE HAVE HAD MOVE THROUGH WERE FARTHER SOUTH THEN THE
MODELS INDICATED. SO DECIDED TO RAISE POPS TO THE LIKELY CATEGORY
AND EVEN THOUGHT ABOUT A WINTER HIGHLIGHT BUT DECIDE AGAINST IT.
SINCE MOST OF THE PRECIP WILL BE RIGHT ALONG THE FRONT AND BEFORE
18Z AND THE SNOW WILL BE ELEVATION DEPENDENT IN THE MORNING.
ANYTHING ABOVE 3000 FT IS LIKELY TO SEE SNOWFALL WHILE EVERY
ELSE IT WILL BE A MIX OF RAIN AND SNOW. AFTER 18Z ONCE THE COLD
AIR ADVECTION BECOMES STRONG THE WINTRY MIX WILL BECOME ALL SNOW
ACROSS THE REGION FROM WEST TO EAST.
ONCE THE PRECIPITATION TURNS OVER TO SNOW IT WILL NOT LAST VERY
LONG SO EXPECT ANY SNOWFALL TOTALS TO BE LESS THE 1/2 AN INCH.
A FEW OF THESE SPOTS ABOVE 3000 FT THAT WILL SEE LONGER PERIODS OF
SNOW SHOWERS WHICH MEANS SLIGHTLY MORE IN THE WAY OF
ACCUMULATION...BUT THE TOTAL WILL REMAIN BELOW 2 INCHES. THE
STRONGER WINDS BEHIND THE FRONT WILL BLOW AROUND THE FALLING SNOW
BUT THE NEW SNOWFALL SHOULD BE FAIRLY WET SO ONCE IT REACHES THE
GROUND IT IS GOING TO BE HARD TO PICK UP.
I DON`T EXPECT ANY FREEZING RAIN WITH THIS SYSTEM BUT SINCE IT
WILL START OUT AS LIGHT RAIN IN MOST AREAS IT COULD PUT ENOUGH
WATER ON THE SURFACE THAT WHEN THE FREEZING TEMPERATURES ARRIVE
LATER IN THE AFTERNOON WE WILL SEE BLACK ICE FORMING ON SURFACES.
ANOTHER THING TO BE LOOKING OUT FOR IN THE AFTERNOON.
THE REST OF THE SHORT TERM FORECAST LOOKS THIS WAY. TUESDAY NIGHT
WINDS DIE OUT AND THE SKIES WILL BECOME PARTLY CLOUDY WITH A
MODIFIED POLAR SURFACE HIGH FROM THE NORTHWEST OVER THE AREA. 850
TEMPS OF -13C WILL MEAN LOWS 5 TO 15. WEAK RIDGING AND WARMING OF
THE AIR MASS FOR WEDNESDAY AND THURSDAY WITH DRY WEATHER AND MOSTLY
CLEAR SKIES. RSMITH
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
THE EXTENDED BEGINS WITH A POSITIVE TILT RIDGE OVER THE NORTHERN
ROCKIES AND NORTHEAST MONTANA. AN UPPER LOW OVER THE SOUTH CENTRAL
CONUS IS BLOCKING UP THE FLOW KEEPING THE NORTHERN BRANCH OF THE
JET OVER NORTHERN CANADIAN PRAIRIES. THIS IS WELL AGREED UPON BY
THE 00Z MODEL SUITE. THE MODELS THEN DIFFER GREATLY ON THE
EJECTION OF THE UPPER LOW INTO THE GREAT LAKES REGION... HOWEVER
FOR NORTHEAST MONTANA THE GFS AND EC EVOLVE INTO A SIMILAR PATTERN
KEEPING THE REGION DRY AND MILD FOR THE REMAINDER OF THE EXTENDED
PERIOD.
THEREFORE THE CONFIDENCE IN MODEL PERFORMANCE IS LOW... THE
OVERALL SOLUTION CONFIDENCE IN THE OPERATIONAL FORECAST IS HIGH.
LOOK FOR AFTERNOON HIGHS IN THE 50S WITH VARIABLE HIGH CLOUDS
THROUGH THE PERIOD. PROTON
&&
.AVIATION...
VFR. A COLD FRONT MOVING THROUGH SOUTHERN SASKATCHEWAN AND CENTRAL
MONTANA THIS MORNING WILL CONTINUE TO MOVE TOWARDS NORTHEAST MONTANA.
THE FRONT SHOULD MOVE THE GLASGOW AREA AROUND 17Z AND EXIT THE
EASTERN AREAS BY 22Z. PRE-FRONTAL LOOK FOR AREAS OF RAIN SHOWERS
AND LOW VFR CONDITIONS. POST FRONTAL MODERATE NORTHWEST WINDS AND
SCATTERED SNOW SHOWERS MAY DROP FLIGHT LEVELS TO MVFR BRIEFLY.
EXPECT VFR TO DOMINATE ALL AREAS BY 03Z. PROTON/AES
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
404 AM MST TUE MAR 6 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
UPPER SPLITTING TROUGH IS MOVING IN FROM THE NORTHWEST AND AS
MODELS HAVE BEEN SAYING OVER THE LAST SEVERAL DAYS. THE UPPER
TROUGH WILL SPLIT WITH MOST OF THE ENERGY FOLLOWING THE SOUTHERN
PART BECOMING A CLOSED CUT OFF SYSTEM OVER THE FOUR CORNERS AREA.
THE NORTHERN PART HAS ALREADY COLLECTED THE QUASI STATIONARY FRONT
ACROSS SOUTHERN CANADA AND WILL PUSH IT SOUTH AND EAST INTO EASTERN
MONTANA AS WE GO THROUGH THE DAY. IT LOOKS LIKE THE REALLY BIG
DROP IN TEMPERATURES WILL OCCUR THIS AFTERNOON AS THE CONTINENTAL
POLAR AIR MASS MOVES IN FROM THE NORTHWEST. MOST HIGHS WILL OCCUR
EARLY TUESDAY WITH MODERATELY STRONG COLD AIR ADVECTION DROPPING
850 MB TEMPS TO AS LOW AS -13C IN OUR N BY 5 PM TUESDAY. WINDS AT
850 MB ARE AROUND 30 KNOTS BEHIND THE FRONT IN THE AFTERNOON SO
EXPECT A MODERATE NORTHWEST WIND MAKING TEMPERATURES FEEL MUCH
COLDER AS THESE WIND MIX TO THE SURFACE.
THE ONE THING ABOUT THIS SYSTEM IS THE MODELS ARE SLIGHTLY OFF ON
PLACEMENT OF THE SURFACE FRONT AND SURFACE LOW THIS MORNING. THE
LATEST 09Z RUC IS IN BETTER AGREEMENT WITH SURFACE OBSERVATIONS
AND THE FRONT IS MUCH FARTHER SOUTH THEN THE 00Z MODELS WERE
INDICATING. THIS IS INTERESTING SINCE THE LAST THREE CLIPPER
SYSTEMS WE HAVE HAD MOVE THROUGH WERE FARTHER SOUTH THEN THE
MODELS INDICATED. SO DECIDED TO RAISE POPS TO THE LIKELY CATEGORY
AND EVEN THOUGHT ABOUT A WINTER HIGHLIGHT BUT DECIDE AGAINST IT.
SINCE MOST OF THE PRECIP WILL BE RIGHT ALONG THE FRONT AND BEFORE
18Z AND THE SNOW WILL BE ELEVATION DEPENDENT IN THE MORNING.
ANYTHING ABOVE 3000 FT IS LIKELY TO SEE SNOWFALL WHILE EVERY
ELSE IT WILL BE A MIX OF RAIN AND SNOW. AFTER 18Z ONCE THE COLD
AIR ADVECTION BECOMES STRONG THE WINTERY MIX WILL BECOME ALL SNOW
ACROSS THE REGION FROM WEST TO EAST.
ONCE THE PRECIPITATION TURNS OVER TO SNOW IT WILL NOT LAST VERY
LONG SO EXPECT ANY SNOWFALL TOTALS TO BE LESS THE 1/2 AN INCH.
A FEW OF THESE SPOTS ABOVE 3000 FT THAT WILL SEE LONGER PERIODS OF
SNOW SHOWERS WHICH MEANS SLIGHTLY MORE IN THE WAY OF
ACCUMULATION...BUT THE TOTAL WILL REMAIN BELOW 2 INCHES. THE
STRONGER WINDS BEHIND THE FRONT WILL BLOW AROUND THE FALLING SNOW
BUT THE NEW SNOWFALL SHOULD BE FAIRLY WET SO ONCE IT REACHES THE
GROUND IT IS GOING TO BE HARD TO PICK UP.
I DON`T EXPECT ANY FREEZING RAIN WITH THIS SYSTEM BUT SINCE IT
WILL START OUT AS LIGHT RAIN IN MOST AREAS IT COULD PUT ENOUGH
WATER ON THE SURFACE THAT WHEN THE FREEZING TEMPERATURES ARRIVE
LATER IN THE AFTERNOON WE WILL SEE BLACK ICE FORMING ON SURFACES.
ANOTHER THING TO BE LOOKING OUT FOR IN THE AFTERNOON.
THE REST OF THE SHORT TERM FORECAST LOOKS THIS WAY. TUESDAY NIGHT
WINDS DIE OUT AND THE SKIES WILL BECOME PARTLY CLOUDY WITH A
MODIFIED POLAR SURFACE HIGH FROM THE NORTHWEST OVER THE AREA. 850
TEMPS OF -13C WILL MEAN LOWS 5 TO 15. WEAK RIDGING AND WARMING OF
THE AIR MASS FOR WEDNESDAY AND THURSDAY WITH DRY WEATHER AND MOSTLY
CLEAR SKIES. RSMITH
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
THE EXTENDED BEGINS WITH A POSITIVE TILT RIDGE OVER THE NORTHERN
ROCKIES AND NORTHEAST MONTANA. AN UPPER LOW OVER THE SOUTH CENTRAL
CONUS IS BLOCKING UP THE FLOW KEEPING THE NORTHERN BRANCH OF THE
JET OVER NORTHERN CANADIAN PRAIRIES. THIS IS WELL AGREED UPON BY
THE 00Z MODEL SUITE. THE MODELS THEN DIFFER GREATLY ON THE
EJECTION OF THE UPPER LOW INTO THE GREAT LAKES REGION... HOWEVER
FOR NORTHEAST MONTANA THE GFS AND EC EVOLVE INTO A SIMILAR PATTERN
KEEPING THE REGION DRY AND MILD FOR THE REMAINDER OF THE EXTENDED
PERIOD.
THEREFORE THE CONFIDENCE IN MODEL PERFORMANCE IS LOW... THE
OVERALL SOLUTION CONFIDENCE IN THE OPERATIONAL FORECAST IS HIGH.
LOOK FOR AFTERNOON HIGHS IN THE 50S WITH VARIABLE HIGH CLOUDS
THROUGH THE PERIOD. PROTON
&&
.AVIATION...
VFR. A COLD FRONT MOVING THROUGH SOUTHERN ALBERTA EARLY THIS
MORNING WILL CONTINUE TO MOVE TOWARDS NORTHEAST MONTANA. THE FRONT
SHOULD MOVE THE GLASGOW AREA AROUND 12Z AND EXIT THE EASTERN AREAS
BY 16Z. PRE-FRONTAL LOOK FOR AREAS OF RAIN SHOWERS AND LOW VFR
CONDITIONS. POST FRONTAL MODERATE NORTHWEST WINDS AND SCATTERED
SNOW SHOWERS MAY DROP FLIGHT LEVELS TO MVFR BRIEFLY. EXPECT VFR TO
DOMINATE ALL AREAS BY 03Z. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
752 PM CST WED MAR 7 2012
.DISCUSSION...MAIN CONCERN WILL BE BAND OF SNOW SHOWERS ACROSS
CENTRAL NORTH DAKOTA ASSOCIATED WITH UPPER WAVE. HRRR INDICATES
THESE SNOW SHOWERS WILL HOLD TOGETHER AS THE FORCING PROPAGATES
THROUGH THE FA. TIMED 30 POPS AND SCATTERED SNOW SHOWERS FOR
TONIGHT. ACCUMULATION WILL BE MINIMAL IF ANYTHING. ALSO ADJUSTED
TEMPS ACCORDING TO HRRR...BUT THIS LED TO ONLY MINIMAL CHANGES.
&&
.AVIATION...A MAJORITY OF THE OVERNIGHT AND MORNING HOURS WILL BE
VFR. HOWEVER...THERE IS A PATCH OF IFR/MVFR CIGS THAT COULD
BRIEFLY AFFECT KTVF AND KFAR THIS EVENING. THEN...THERE IS A
NARROW BAND OF SNOW SHOWERS THAT WILL MOVE THROUGH THE REGION
LATER IN THE NIGHT. WINDS ON THURSDAY WILL BE 20-30 KNOTS.
&&
.PREV DISCUSSION... /ISSUED 309 PM CST WED MAR 7 2012/
SHORT TERM...
CHALLENGES FOR THE FORECAST INCLUDE EXTENT OF WARM UP FOR THE END
OF THE WEEK AND A CONCERN FOR LIGHT SNOW THURSDAY WITH THE PASSAGE
OF A WEAK WAVE TO OUR NORTH. MODELS IN GOOD AGREEMENT AND WILL USE
A BLEND FOR THE FORECAST.
TONIGHT EXPECTING THE CLEAR SKIES UNDER THE WEAK SFC RIDGE AXIS
CURRENTLY EXTENDING FROM NW ND NE ACROSS CENTRAL MANITOBA TO SLIDE
EAST AND ALLOW SOME RADIATIONAL COOLING. HOWEVER THE NEXT TROUGH
OF LOW PRESSURE WILL BRING SOME CLOUDS INTO THE FA QUICKLY SLOWING
NIGHTTIME COOLING. WINDY TOMORROW BEHIND FROPA AND 850MB WINDS BETWEEN
30 AND 40KTS AND WITH A NEARLY ADIABATIC MIXED LAYER COULD SEE
SOME OF THE GUSTS REALIZE THAT POTENTIAL ESPECIALLY IN THE HIGHER
DVL BSN ELEVATIONS.
THURSDAY EVENING WINDS QUICKLY DECOUPLE AS 1030MB SOMETHING SFC HIGH
PRESSURE MOVES INTO THE REGION. CENTER OF THE HIGH WITH 850MB
TEMPS IN THE -5 TO -10 C SHOULD BE OVER EASTERN ZONES FRI AM AND
SO WENT MUCH COOLER WITH LOWS TOWARD THE GEM GUIDANCE BUT NOT AS
COLD...SINGLE DIGITS NRRV AND EASTERN ZONES.
WARM UP FOR THE WEEKEND BEGINS FRIDAY AS 500MB RIDGING AND
THICKNESSES INCREASE WITH STRONG LOW LEVEL WAA AS 850MB TEMPS
INCREASE TO 8 TO 12 C BY SATURDAY AFTERNOON. HIGHS FRIDAY WILL
STRUGGLE AS SSE VALLEY WINDS NOT FAVORABLE FOR EFFICIENT
WARMING...MUCH LIKE THIS PAST MONDAY. WINDS TO SHIFT TO THE WEST
FOR SATURDAY WITH AFOREMENTIONED 850MB TEMPS AND GOOD MIXING WILL
SEE HIGHS IN THE UPPER 40S TO LOW 50S WHERE SNOW PACK IS
NONEXISTENT.
LONG TERM...
MODEL PROGS LIFT AN UPPER LOW NEWD ACROSS THE CENTRAL PLAINS ON SUN
THEN INTO THE GTLKS REGION ON MON. TIMING AND PLACEMENT OF THIS
SYSTEM IS IN DISAGREEMENT AMONGST THE MODELS WITH THE ECMWF THE
QUICKEST AND THE GEM KEEPING THE LOW MUCH FURTHER SOUTH. THE NET
RESULT IS A SLIGHT CHC OF RAIN FOR THE FAR SW ZONES SUN/SUN
NIGHT...THOUGH LOOKING LESS PROBABLE WITH EACH MODEL RUN. WITH THE
UPPER LOW OFF TO THE EAST BUILDING HEIGHTS AND WARMING 8H TEMPS
SHOULD BRING OUR FIRST OPPORTUNITY FOR EXCEEDING 50 DEGREES BY MON
FOLLOWED BY NEAR 60 DEGREE TEMPS IN THE FAR SOUTHERN ZONES ON WED.
THE QUESTION WILL BE HOW FAST THE SNOW PACK MELTS AND THE AMOUNT
OF MIXING FOR NEXT WEEK...THOUGH A WESTERLY WINDS SHOULD HELP. THE
WARMTH SHOULD CONTINUE THRU NEXT WEEK BEFORE THE NEXT SYSTEM
APPROACHES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
208 AM MST THU MAR 8 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 200 AM MST THU MAR 8 2012
THE UPPER LEVEL LOW WAS SAGGING SOUTH ALONG THE AZ-NM BORDER THIS
MORNING THEN WILL EJECT SLOWLY EAST ACROSS SOUTHERN NM THIS
AFTERNOON. ASSOCIATED DYNAMICAL LIFT IS SOUTH OF THE CWA AND WRAP-
AROUND MOISTURE IS LIMITED. THIS WOULD PRODUCE SOME LIGHT
ACCUMULATION IN THE VICINITY OF MONARCH...SLUMGULLION...AND WOLF
CREEK PASSES TODAY. THE HRRR AND NAM12 ALSO PRODUCE LIGHT
ACCUMULATION OVER THE MANCOS RIDGE THROUGH THIS AFTERNOON.
OTHERWISE MOSTLY SUNNY SKIES WILL PREVAIL.
AT THE SURFACE LOW PRESSURE NEAR THE FOUR CORNERS AND COLD HIGH
PRESSURE PUSHING DOWN THE FRONT RANGE IS PRODUCING NE GRADIENT
WINDS. MTN TOP NE WINDS ARE GUSTING 20-30 OVER EXPOSED TERRAIN.
THE GRADIENT RELAXES THROUGH THE AFTERNOON.
TONIGHT THE UPPER LOW SETTLES ONTO THE EASTERN NM PLAINS WHERE IT
WILL LANGUISH INTO THE WEEKEND. THIS KEEPS THE FORECAST AREA IN A
LIGHT EAST FLOW ALOFT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 256 PM MST WED MAR 7 2012
MEDIUM RANGE MODELS CONTINUE TO SHOW THE LOW SITTING OVER THE
EASTERN NEW MEXICO AND WEST TEXAS REGIONS THROUGH FRIDAY...BEFORE
IT EJECTS NORTH NORTHEAST INTO THE PLAINS THIS WEEKEND. NOT
ANTICIPATING MUCH IN THE WAY OF IMPACT ON OUR FORECAST
AREA...ALTHOUGH CANNOT RULE OUT A STRAY SHOWER OR TWO FOR THE
EASTERN STRETCHES OF OUR SAN JUAN MOUNTAINS. HIGH PRESSURE WILL
FINALLY PUSH ACROSS THE FORECAST AREA BY SUNDAY WITH TEMPS
CLIMBING BACK TO ABOVE SEASONAL NORMS. THE RIDGE TRANSLATES EAST
BY EARLY NEXT WEEK...WITH SOUTHWEST FLOW STRENGTHENING AS A NEW
WAVE OF PACIFIC STORMS PLOWS INTO THE PAC NW. THIS WILL BRING A
RETURN TO MORE SPRING LIKE WINDS OVER THE REGION...WITH BREEZY TO
WINDY CONDITIONS EXPECTED MONDAY THROUGH WEDNESDAY. FEW WEAK
DISTURBANCES WILL ALSO PASS THROUGH...ONE MONDAY NIGHT AND ANOTHER
TUESDAY NIGHT...BRINGING A SLIGHT CHANCE OF MOUNTAINS SHOWERS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 200 AM MST THU MAR 8 2012
VFR CONDITIONS WILL DOMINATE INTO FRIDAY. THE EXCEPTION IS SCT SNOW
SHOWERS IN THE SOUTHERN MTNS ALONG AND EAST OF HIGHWAY 550. EXPECT
SCT MVFR CIGS AND VSBY THROUGH THE AFTERNOON THERE WITH MTN TOPS
OCNLY OBSCURED. WIDESPREAD SNOW SHOWERS WILL OCCUR OVER AND EAST
OF MONARCH...SLUMGULLION...AND WOLF CREEK PASSES THAT WILL PRODUCE
MVFR/LOCAL IFR CIGS AND VSBY. ALL OF THESE SOUTHERN SHOWERS WILL
DIMINISH QUICKLY AFTER 6 PM THIS EVENING WITH VFR CONDITIONS
PREVAILING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JOE
LONG TERM....JDC
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
344 AM CST THU MAR 8 2012
.DISCUSSION...
307 AM CST
THE IMMEDIATE CONCERNS WITH THE FORECAST ARE WITH THE FALLING
TEMPERATURES...AS WELL AS CONTINUED POST FRONTAL SHOWERS AND EVEN
SOME THUNDER CHANCES THIS MORNING ACROSS THE SOUTHERN HALF OF THE
AREA. THEN ATTENTION TURNS TO RAIN POTENTIAL SUNDAY...FOLLOWED BY
THE TEMPERATURES NEXT WEEK AS A SIGNIFICANT WARM UP...OR RE-WARM UP
WE SHOULD SAY...LOOKS LIKELY.
FOR THE CURRENT SITUATION...A VERY WELL-DEFINED COLD FRONT IS
CLEARING THE FORECAST AREA EARLY THIS MORNING. ROBUSTLY WARM AIR
AHEAD OF THIS FEATURE HELPED CHICAGO BREAK THEIR RECORD WARM LOW
FOR YESTERDAY /54 DEGREES/. THE COMBINATION OF THE FRONTAL PASSAGE
AND RAIN TOOK TEMPERATURES DOWN AS MUCH AS 14 DEGREES IN ONE
HOUR AT SOME LOCATIONS. A GOOD PART OF THE SHOWER ACTIVITY IS
POST-FRONTAL...ASSOCIATED WITH ELEVATED MOISTURE TRANSPORT AND
STRONG CONVERGENCE ALONG THE BOUNDARY. ITS A GOOD THING A LOT OF
THIS IS POST FRONTAL...AS MORE SHOWER ACTIVITY AHEAD OF THE FRONT
COULD HAVE POTENTIALLY STEERED DOWN SOME OF THE 55 KT FLOW AT 1500
FT SEEN ON THE KLOT DOPPLER VELOCITY FOR HOURS AHEAD OF THE FRONT.
THE NORTHWEST WIND SPEEDS BEHIND THE FRONT ARE ACTUALLY QUITE A
BIT LOWER...GUSTING AT TIMES TO NEAR 25 MPH. THIS SHOULD CONTINUE
TO BE THE CASE INTO THIS AFTERNOON.
AN INTERESTING AREA OF ELEVATED CONVECTION IS SEEN IN NORTHERN MO
AS OF 300 AM HAVING ORIGINATED IN KS WITH A SHORT WAVE PER WATER
VAPOR ANALYSIS. THIS AREA CONTINUES TO GROW UPSCALE EAST
NORTHEAST...WELL BEHIND THE FRONT. RUC AND NAM CROSS SECTIONS
THROUGH THIS AREA SHOW STRONG MID-LEVEL FRONTOGENESIS AND A VERY
DEEP LAYER /AROUND 200 MB/ OF NEGATIVE EPV AND SLIGHTLY
DECREASING THETA-E...INDICATING CONVECTIVE INSTABILITY PRESENT.
THE RUC FORECAST FOR THE FORCING AND INSTABILITY...AND HRRR
PROJECTION OF REFLECTIVITY...SEEMS TO HAVE A STRONG HANDLE ON
THIS...WHILE MOST OTHER GUIDANCE DOES NOT. THIS AREA IS FORECAST
BY THE RUC/HRRR TO COME ACROSS THE SOUTHERN HALF OF THE FORECAST
AREA EARLY THIS MORNING. THE CONVECTIVE SIGNAL WEAKENS
SOMEWHAT...BUT STILL THINK ISOLATED TO SCATTERED THUNDER SHOULD BE
SEEN AT LEAST CLOSE IF NOT INTO THE SOUTHERN FORECAST AREA. THERE
COULD BE SOME SMALL HAIL WITH THIS GIVEN THE LOW WET BULB ZERO
VALUES. THIS SHOULD EXIT BY 10 AM TO NOON...WITH LINGERING CLOUDS
BEHIND THE FRONT ACROSS THE SOUTHERN AREA INTO EARLY TO MID
AFTERNOON.
COLD AIR ADVECTION BEHIND THE FRONT WILL UNDERCUT THE MORNING
CLOUDS AND SHOWERS IN THE SOUTH...HELPING TO KEEP TEMPERATURES
NEARLY STEADY OR EVEN CONTINUING TO FALL THROUGH MID-MORNING.
CLEARING BY LATE MORNING INTO AFTERNOON WILL ALLOW FOR SOME
REBOUND...BUT PROBABLY ONLY INTO THE LOWER TO MID 40S. CONFIDENCE
ON THE DEGREE OF RECOVERY IS SOMEWHAT LOW DUE TO WEIGHING THE COLD
AIR ADVECTION/CLOUD IMPACT THIS MORNING.
THE UPPER TROUGH OVER MN EARLY THIS MORNING WILL PASS OVER THE
GREAT LAKES AND BE RE-ENFORCED BY A STRONG JET MAX TO THE
NORTHWEST. THIS WILL HELP TO PUSH A SECONDARY COLD FRONT SOUTH
THROUGH THE AREA LATE THIS EVENING INTO OVERNIGHT. THIS LOOKS TO
REALLY SEND DEW POINTS DOWN AND POTENTIALLY TEMPERATURES FURTHER
TOO. THE COLD POCKET ASSOCIATED WITH THIS SHOULD DEVELOP SOME
STRATOCU TONIGHT ACROSS NORTHERN AND EASTERN AREAS THAT MAY
POTENTIALLY LINGER INTO FRI MORNING.
HIGH PRESSURE WILL THEN PREVAIL FRIDAY INTO EARLY SATURDAY...WITH
RETURN FLOW THEN SETTING UP FOR SATURDAY...WHICH SHOULD BE A
FAIRLY PLEASANT AND SUNNY DAY. THE WELL-ORGANIZED CLOSED UPPER
LOW OVER THE DESERT SOUTHWEST WILL DRIFT GRADUALLY NORTHEAST ON
SATURDAY...THEN BEGIN TO BECOME MORE NEUTRAL TO NEGATIVELY TILED
AS IT LIFTS OVER OUR AREA ON SUNDAY INTO SUNDAY NIGHT. THE
AMOUNT OF MOISTURE RETURN AHEAD OF THIS IS FAIRLY SHORT IN
DURATION...BUT IT CERTAINLY LOOKS TO BE DEEP ENOUGH AND WITHIN
STRONG ENOUGH ISENTROPIC LIFT FOR FAIRLY WIDESPREAD RAIN/SHOWERS
ON SUNDAY. HAVE CONTINUED TO INCH UP POPS. WHILE THE SYSTEM DRY
SLOT EVOLVES RIGHT INTO THE AREA...ELEVATED INSTABILITY IS VERY
MARGINAL DUE TO THE LIMITED DEGREE OF THETA-E RETURN. SO CONTINUE
WITH NO THUNDER MENTION...BUT COULD SEE SOME GUSTIER SHOWERS
POTENTIALLY SUNDAY AFTERNOON AND EVE IF THE GFS/EC PAN OUT AS IS.
SO HAVE MENTIONED MORE OF A SHOWER WORDING DURING THE AFTERNOON
AND EVE BECAUSE OF THIS. TEMPERATURES ON SUNDAY COULD ENCOMPASS A
FAIRLY LARGE RANGE THANKS TO THE IMPACTS OF THE LIKELY RAIN. WITH
CONFIDENCE INCREASING IN RAIN...HAVE CONTINUED NOT TO INCREASE
TEMPERATURES DESPITE SOME GUIDANCE INDICATING WARMER IN SUCCESSIVE
RUNS.
THE GFS REMAINS CONSISTENT WITH HAVING ANOTHER UPPER
WAVE...ACTUALLY ALMOST A PART OF THE FIRST ONE...MOVE NORTHEAST
ACROSS THE OHIO RIVER VALLEY ON MONDAY NIGHT INTO TUESDAY. THE
08.00 EC TRENDED BACK AWAY FROM THIS...BUT HAS BEEN THE LESS
CONSISTENT MODEL. HAVE KEPT POPS ON TUE MAINLY IN SOUTHEAST AREAS
TO ACCOUNT FOR THIS WAVE. WHILE THIS COULD HAVE IMPACTS ON
TEMPERATURES ON TUE...A LOW-LEVEL THERMAL TONGUE IS PROJECTED TO
BE KNOCKING ON OUR DOOR FROM THE WEST AND SHOULD PROVIDE FOR ABOVE
TO WELL ABOVE NORMAL TEMPERATURES. THE STRONGEST SIGNAL FOR VERY
MILD READINGS AND A DRY ATMOSPHERIC COLUMN IS ON WED AT THIS TIME.
AS PREVIOUS SHIFT DID...LEAN THE FORECAST TOWARDS THE BETTER
PERFORMING EC IN THOSE TYPE OF REGIMES. HIGHS IN THE UPPER 60S
INTO THE 70S ARE CURRENTLY WHAT THIS BLENDED APPROACH PRODUCES
AND SEEMS TO MAKE SENSE. WHILE A FRONT IS PRESENTLY FORECAST TO
MOVE THROUGH SOMETIME LATER WED INTO THU OF NEXT WEEK...IT WOULD
SEEM LIKELY WITH THE PATTERN THAT ABOVE NORMAL TEMPERATURES
CONTINUE THROUGH THE LATTER PART OF NEXT WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 10Z...
* WEST WINDS SHIFTING TO NORTHWEST THIS MORNING WITH OCNL GUSTS TO
20-25KT.
* OCNL SHOWERS/SPRINKLES/DRIZZLE THROUGH ARND 14Z.
* MVFR AND OCNL IFR CEILINGS THROUGH LATE MORNING.
KREIN
//DISCUSSION...UPDATED 06Z...
SCATTERED SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF NORTHERN
ILLINOIS THIS EVENING. THIS ACTIVITY IS ASSOCIATED WITH A COLD
FRONT...WHICH IS CURRENTLY APPROACHING THE ROCKFORD AREA. THIS
FRONT WILL QUICKLY MOVE ACROSS ALL OF NORTHEASTERN ILLINOIS AND
NORTHWESTERN INDIANA OVERNIGHT TONIGHT. THE FRONTAL PASSAGE WILL
RESULT IN A WIND SWITCH OUT OF THE NORTHWEST OVER THE NEXT SEVERAL
HOURS.
SHOWERS AND POTENTIALLY A THUNDERSTORM WILL AFFECT THE TERMINALS FOR
A BRIEF PERIOD ALONG AND AHEAD OF THE FRONTAL ZONE. IT APPEARS
THAT THE BEST TIMING FOR CONVECTION WILL WITHIN THE NEXT HOUR OR
TWO AT KRFD...06-09 UTC FOR KORD AND KMDW AND 07 TO 10 UTC AT
KGYY. MUCH IF NOT ALL OF THE PRECIPITATION WILL END DURING THE
PREDAWN HOURS ON THURSDAY MORNING. ASIDE FROM THE POTENTIAL FOR A
BRIEF PERIOD OF LOW MVFR CIGS OR IFR CIGS AFTER THE FRONTAL
PASSAGE LATE TONIGHT...CIGS SHOULD QUICKLY REBOUND DURING THE
MORNING HOURS ON THURSDAY WITH VFR CONDITIONS EXPECTED TO QUICKLY
RETURN.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 10Z...
* MODERATE-HIGH CONFIDENCE WITH WIND TRENDS FOR THE REMAINDER OF
THE MORNING AND THROUGH TODAY.
* MODERATE CONFIDENCE IN WIND TRENDS LATER TONIGHT.
* MODERATE CONFIDENCE IN CEILING TRENDS THROUGH LATE THIS MORNING.
* HIGH CONFIDENCE IN CIG/VIS TRENDS FROM LATE MORNING THROUGH
TOMORROW MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...VFR.
* SUNDAY AND MONDAY...CHANCE OF RAIN. MVFR POSSIBLE.
* TUESDAY...VFR.
KJB
&&
.MARINE...
325 AM CST
SOUTHWEST GALES ARE FINALLY COMING TO AN END OVER THE LAKE! THE
COLD FRONT IS ALMOST THROUGH LAKE MICHIGAN...WITH THE
SOUTHEASTERN THIRD OF THE LAKE STILL AWAITING ITS ARRIVAL. WINDS
BEHIND THE COLD FRONT HAVE DIMINISHED AND TURNED WEST TO
NORTHWEST. THE ABRUPT CHANGE IN WIND SPEED AND DIRECTION HAS
HELPED WAVES QUICKLY DIMINISH IN THE NEAR SHORE ZONES...THEREFORE
NOT ISSUING A SMALL CRAFT ADVISORY FOR THIS MORNING. WINDS MAY
GUST TO 25 KT FOR THE NEXT COUPLE OF HOURS...BUT NOT LONG ENOUGH
TO WARRANT A SMALL CRAFT ADVISORY.
A WEAKENING LOW MOVES SOUTH OVER THE EASTERN GREAT LAKES AS THE HIGH
PRESSURE TO OUR WEST MOVES INTO SOUTHERN MINNESOTA. AS THE TWO
SYSTEMS MOVE CLOSER TOGETHER THE PRESSURE GRADIENT TIGHTENS
OVERHEAD. THAT COMBINED WITH STRONG PRESSURE RISES WILL CREATE
NORTHWEST GALES OVER THE NORTHERN TWO THIRDS OF THE LAKE LATE
TONIGHT. GALES WILL BEGIN TO DIMINISH FRIDAY MORNING AS THE HIGH
PRESSURE MOVES INTO THE IMMEDIATE AREA. THE HIGH WILL PASS OVER
THE LAKE LATE FRIDAY AFTERNOON INTO FRIDAY EVENING.
YET ANOTHER ROUND OF GALES IS POSSIBLE ON THE BACKSIDE OF THE HIGH
PRESSURE SATURDAY MORNING. LOW END GALES ARE EXPECTED OVER THE
CENTRAL THIRD OF THE LAKE...WITH GALES UP TO 40 KT LIKELY OVER THE
NORTHERN THIRD OF THE LAKE. NOT ANTICIPATING GALES OVER THE
SOUTHERN THIRD OF THE LAKE. GALES BEGIN TO DIMINISH SATURDAY
AFTERNOON AS THE HIGH PRESSURE PULLS AWAY TO THE EAST...HOWEVER
GALES OVER THE NORTHERN END OF THE LAKE LOOK LIKE THEY WILL PERSIST
INTO THE EVENING HOURS.
MODELS HAVE SIGNIFICANT DISCREPANCIES IN TIMING AND THE OVERALL
PATTERN FOR THE REMAINDER OF THE FORECAST...SO WHILE NO GALES ARE
FORECAST FOR NEXT WEEK...FORECAST CONFIDENCE IS LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 4 AM THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
329 AM CST THU MAR 8 2012
.DISCUSSION...
307 AM CST
THE IMMEDIATE CONCERNS WITH THE FORECAST ARE WITH THE FALLING
TEMPERATURES...AS WELL AS CONTINUED POST FRONTAL SHOWERS AND EVEN
SOME THUNDER CHANCES THIS MORNING ACROSS THE SOUTHERN HALF OF THE
AREA. THEN ATTENTION TURNS TO RAIN POTENTIAL SUNDAY...FOLLOWED BY
THE TEMPERATURES NEXT WEEK AS A SIGNIFICANT WARM UP...OR RE-WARM UP
WE SHOULD SAY...LOOKS LIKELY.
FOR THE CURRENT SITUATION...A VERY WELL-DEFINED COLD FRONT IS
CLEARING THE FORECAST AREA EARLY THIS MORNING. ROBUSTLY WARM AIR
AHEAD OF THIS FEATURE HELPED CHICAGO BREAK THEIR RECORD WARM LOW
FOR YESTERDAY /54 DEGREES/. THE COMBINATION OF THE FRONTAL PASSAGE
AND RAIN TOOK TEMPERATURES DOWN AS MUCH AS 14 DEGREES IN ONE
HOUR AT SOME LOCATIONS. A GOOD PART OF THE SHOWER ACTIVITY IS
POST-FRONTAL...ASSOCIATED WITH ELEVATED MOISTURE TRANSPORT AND
STRONG CONVERGENCE ALONG THE BOUNDARY. ITS A GOOD THING A LOT OF
THIS IS POST FRONTAL...AS MORE SHOWER ACTIVITY AHEAD OF THE FRONT
COULD HAVE POTENTIALLY STEERED DOWN SOME OF THE 55 KT FLOW AT 1500
FT SEEN ON THE KLOT DOPPLER VELOCITY FOR HOURS AHEAD OF THE FRONT.
THE NORTHWEST WIND SPEEDS BEHIND THE FRONT ARE ACTUALLY QUITE A
BIT LOWER...GUSTING AT TIMES TO NEAR 25 MPH. THIS SHOULD CONTINUE
TO BE THE CASE INTO THIS AFTERNOON.
AN INTERESTING AREA OF ELEVATED CONVECTION IS SEEN IN NORTHERN MO
AS OF 300 AM HAVING ORIGINATED IN KS WITH A SHORT WAVE PER WATER
VAPOR ANALYSIS. THIS AREA CONTINUES TO GROW UPSCALE EAST
NORTHEAST...WELL BEHIND THE FRONT. RUC AND NAM CROSS SECTIONS
THROUGH THIS AREA SHOW STRONG MID-LEVEL FRONTOGENESIS AND A VERY
DEEP LAYER /AROUND 200 MB/ OF NEGATIVE EPV AND SLIGHTLY
DECREASING THETA-E...INDICATING CONVECTIVE INSTABILITY PRESENT.
THE RUC FORECAST FOR THE FORCING AND INSTABILITY...AND HRRR
PROJECTION OF REFLECTIVITY...SEEMS TO HAVE A STRONG HANDLE ON
THIS...WHILE MOST OTHER GUIDANCE DOES NOT. THIS AREA IS FORECAST
BY THE RUC/HRRR TO COME ACROSS THE SOUTHERN HALF OF THE FORECAST
AREA EARLY THIS MORNING. THE CONVECTIVE SIGNAL WEAKENS
SOMEWHAT...BUT STILL THINK ISOLATED TO SCATTERED THUNDER SHOULD BE
SEEN AT LEAST CLOSE IF NOT INTO THE SOUTHERN FORECAST AREA. THERE
COULD BE SOME SMALL HAIL WITH THIS GIVEN THE LOW WET BULB ZERO
VALUES. THIS SHOULD EXIT BY 10 AM TO NOON...WITH LINGERING CLOUDS
BEHIND THE FRONT ACROSS THE SOUTHERN AREA INTO EARLY TO MID
AFTERNOON.
COLD AIR ADVECTION BEHIND THE FRONT WILL UNDERCUT THE MORNING
CLOUDS AND SHOWERS IN THE SOUTH...HELPING TO KEEP TEMPERATURES
NEARLY STEADY OR EVEN CONTINUING TO FALL THROUGH MID-MORNING.
CLEARING BY LATE MORNING INTO AFTERNOON WILL ALLOW FOR SOME
REBOUND...BUT PROBABLY ONLY INTO THE LOWER TO MID 40S. CONFIDENCE
ON THE DEGREE OF RECOVERY IS SOMEWHAT LOW DUE TO WEIGHING THE COLD
AIR ADVECTION/CLOUD IMPACT THIS MORNING.
THE UPPER TROUGH OVER MN EARLY THIS MORNING WILL PASS OVER THE
GREAT LAKES AND BE RE-ENFORCED BY A STRONG JET MAX TO THE
NORTHWEST. THIS WILL HELP TO PUSH A SECONDARY COLD FRONT SOUTH
THROUGH THE AREA LATE THIS EVENING INTO OVERNIGHT. THIS LOOKS TO
REALLY SEND DEW POINTS DOWN AND POTENTIALLY TEMPERATURES FURTHER
TOO. THE COLD POCKET ASSOCIATED WITH THIS SHOULD DEVELOP SOME
STRATOCU TONIGHT ACROSS NORTHERN AND EASTERN AREAS THAT MAY
POTENTIALLY LINGER INTO FRI MORNING.
HIGH PRESSURE WILL THEN PREVAIL FRIDAY INTO EARLY SATURDAY...WITH
RETURN FLOW THEN SETTING UP FOR SATURDAY...WHICH SHOULD BE A
FAIRLY PLEASANT AND SUNNY DAY. THE WELL-ORGANIZED CLOSED UPPER
LOW OVER THE DESERT SOUTHWEST WILL DRIFT GRADUALLY NORTHEAST ON
SATURDAY...THEN BEGIN TO BECOME MORE NEUTRAL TO NEGATIVELY TILED
AS IT LIFTS OVER OUR AREA ON SUNDAY INTO SUNDAY NIGHT. THE
AMOUNT OF MOISTURE RETURN AHEAD OF THIS IS FAIRLY SHORT IN
DURATION...BUT IT CERTAINLY LOOKS TO BE DEEP ENOUGH AND WITHIN
STRONG ENOUGH ISENTROPIC LIFT FOR FAIRLY WIDESPREAD RAIN/SHOWERS
ON SUNDAY. HAVE CONTINUED TO INCH UP POPS. WHILE THE SYSTEM DRY
SLOT EVOLVES RIGHT INTO THE AREA...ELEVATED INSTABILITY IS VERY
MARGINAL DUE TO THE LIMITED DEGREE OF THETA-E RETURN. SO CONTINUE
WITH NO THUNDER MENTION...BUT COULD SEE SOME GUSTIER SHOWERS
POTENTIALLY SUNDAY AFTERNOON AND EVE IF THE GFS/EC PAN OUT AS IS.
SO HAVE MENTIONED MORE OF A SHOWER WORDING DURING THE AFTERNOON
AND EVE BECAUSE OF THIS. TEMPERATURES ON SUNDAY COULD ENCOMPASS A
FAIRLY LARGE RANGE THANKS TO THE IMPACTS OF THE LIKELY RAIN. WITH
CONFIDENCE INCREASING IN RAIN...HAVE CONTINUED NOT TO INCREASE
TEMPERATURES DESPITE SOME GUIDANCE INDICATING WARMER IN SUCCESSIVE
RUNS.
THE GFS REMAINS CONSISTENT WITH HAVING ANOTHER UPPER
WAVE...ACTUALLY ALMOST A PART OF THE FIRST ONE...MOVE NORTHEAST
ACROSS THE OHIO RIVER VALLEY ON MONDAY NIGHT INTO TUESDAY. THE
08.00 EC TRENDED BACK AWAY FROM THIS...BUT HAS BEEN THE LESS
CONSISTENT MODEL. HAVE KEPT POPS ON TUE MAINLY IN SOUTHEAST AREAS
TO ACCOUNT FOR THIS WAVE. WHILE THIS COULD HAVE IMPACTS ON
TEMPERATURES ON TUE...A LOW-LEVEL THERMAL TONGUE IS PROJECTED TO
BE KNOCKING ON OUR DOOR FROM THE WEST AND SHOULD PROVIDE FOR ABOVE
TO WELL ABOVE NORMAL TEMPERATURES. THE STRONGEST SIGNAL FOR VERY
MILD READINGS AND A DRY ATMOSPHERIC COLUMN IS ON WED AT THIS TIME.
AS PREVIOUS SHIFT DID...LEAN THE FORECAST TOWARDS THE BETTER
PERFORMING EC IN THOSE TYPE OF REGIMES. HIGHS IN THE UPPER 60S
INTO THE 70S ARE CURRENTLY WHAT THIS BLENDED APPROACH PRODUCES
AND SEEMS TO MAKE SENSE. WHILE A FRONT IS PRESENTLY FORECAST TO
MOVE THROUGH SOMETIME LATER WED INTO THU OF NEXT WEEK...IT WOULD
SEEM LIKELY WITH THE PATTERN THAT ABOVE NORMAL TEMPERATURES
CONTINUE THROUGH THE LATTER PART OF NEXT WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WINDS SHIFTING TO WEST NORTHWEST BETWEEN 08 AND 09 UTC TONIGHT
WITH FROPA.
* PERIODS OF SHOWERS AND THE POTENTIAL FOR A RUMBLE OF THUNDER
FOR A SHORT PERIOD THROUGH 09 UTC.
* MVFR/IFR CEILINGS POSSIBLE FOLLOWING THE FROPA.
KJB
//DISCUSSION...UPDATED 06Z...
SCATTERED SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF NORTHERN
ILLINOIS THIS EVENING. THIS ACTIVITY IS ASSOCIATED WITH A COLD
FRONT...WHICH IS CURRENTLY APPROACHING THE ROCKFORD AREA. THIS
FRONT WILL QUICKLY MOVE ACROSS ALL OF NORTHEASTERN ILLINOIS AND
NORTHWESTERN INDIANA OVERNIGHT TONIGHT. THE FRONTAL PASSAGE WILL
RESULT IN A WIND SWITCH OUT OF THE NORTHWEST OVER THE NEXT SEVERAL
HOURS.
SHOWERS AND POTENTIALLY A THUNDERSTORM WILL AFFECT THE TERMINALS FOR
A BRIEF PERIOD ALONG AND AHEAD OF THE FRONTAL ZONE. IT APPEARS
THAT THE BEST TIMING FOR CONVECTION WILL WITHIN THE NEXT HOUR OR
TWO AT KRFD...06-09 UTC FOR KORD AND KMDW AND 07 TO 10 UTC AT
KGYY. MUCH IF NOT ALL OF THE PRECIPITATION WILL END DURING THE
PREDAWN HOURS ON THURSDAY MORNING. ASIDE FROM THE POTENTIAL FOR A
BRIEF PERIOD OF LOW MVFR CIGS OR IFR CIGS AFTER THE FRONTAL
PASSAGE LATE TONIGHT...CIGS SHOULD QUICKLY REBOUND DURING THE
MORNING HOURS ON THURSDAY WITH VFR CONDITIONS EXPECTED TO QUICKLY
RETURN.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE WITH WIND SPEED/GUSTS AND DIRECTION...AND WITH
WIND SHIFT WITH FROPA.
* LOW TO MEDIUM CONFIDENCE WITH THUNDER TRENDS/TIMING.
* HIGH CONFIDENCE WITH MVFR CEILINGS TONIGHT AND MEDIUM CONFIDENCE
WITH A BRIEF PERIOD OF IFR CEILINGS LATER TONIGHT.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...VFR.
* SUNDAY AND MONDAY...CHANCE OF RAIN. MVFR POSSIBLE.
* TUESDAY...VFR.
KJB
&&
.MARINE...
325 AM CST
SOUTHWEST GALES ARE FINALLY COMING TO AN END OVER THE LAKE! THE
COLD FRONT IS ALMOST THROUGH LAKE MICHIGAN...WITH THE
SOUTHEASTERN THIRD OF THE LAKE STILL AWAITING ITS ARRIVAL. WINDS
BEHIND THE COLD FRONT HAVE DIMINISHED AND TURNED WEST TO
NORTHWEST. THE ABRUPT CHANGE IN WIND SPEED AND DIRECTION HAS
HELPED WAVES QUICKLY DIMINISH IN THE NEAR SHORE ZONES...THEREFORE
NOT ISSUING A SMALL CRAFT ADVISORY FOR THIS MORNING. WINDS MAY
GUST TO 25 KT FOR THE NEXT COUPLE OF HOURS...BUT NOT LONG ENOUGH
TO WARRANT A SMALL CRAFT ADVISORY.
A WEAKENING LOW MOVES SOUTH OVER THE EASTERN GREAT LAKES AS THE HIGH
PRESSURE TO OUR WEST MOVES INTO SOUTHERN MINNESOTA. AS THE TWO
SYSTEMS MOVE CLOSER TOGETHER THE PRESSURE GRADIENT TIGHTENS
OVERHEAD. THAT COMBINED WITH STRONG PRESSURE RISES WILL CREATE
NORTHWEST GALES OVER THE NORTHERN TWO THIRDS OF THE LAKE LATE
TONIGHT. GALES WILL BEGIN TO DIMINISH FRIDAY MORNING AS THE HIGH
PRESSURE MOVES INTO THE IMMEDIATE AREA. THE HIGH WILL PASS OVER
THE LAKE LATE FRIDAY AFTERNOON INTO FRIDAY EVENING.
YET ANOTHER ROUND OF GALES IS POSSIBLE ON THE BACKSIDE OF THE HIGH
PRESSURE SATURDAY MORNING. LOW END GALES ARE EXPECTED OVER THE
CENTRAL THIRD OF THE LAKE...WITH GALES UP TO 40 KT LIKELY OVER THE
NORTHERN THIRD OF THE LAKE. NOT ANTICIPATING GALES OVER THE
SOUTHERN THIRD OF THE LAKE. GALES BEGIN TO DIMINISH SATURDAY
AFTERNOON AS THE HIGH PRESSURE PULLS AWAY TO THE EAST...HOWEVER
GALES OVER THE NORTHERN END OF THE LAKE LOOK LIKE THEY WILL PERSIST
INTO THE EVENING HOURS.
MODELS HAVE SIGNIFICANT DISCREPANCIES IN TIMING AND THE OVERALL
PATTERN FOR THE REMAINDER OF THE FORECAST...SO WHILE NO GALES ARE
FORECAST FOR NEXT WEEK...FORECAST CONFIDENCE IS LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 4 AM THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
308 AM CST THU MAR 8 2012
.DISCUSSION...
307 AM CST
THE IMMEDIATE CONCERNS WITH THE FORECAST ARE WITH THE FALLING
TEMPERATURES...AS WELL AS CONTINUED POST FRONTAL SHOWERS AND EVEN
SOME THUNDER CHANCES THIS MORNING ACROSS THE SOUTHERN HALF OF THE
AREA. THEN ATTENTION TURNS TO RAIN POTENTIAL SUNDAY...FOLLOWED BY
THE TEMPERATURES NEXT WEEK AS A SIGNIFICANT WARM UP...OR RE-WARM UP
WE SHOULD SAY...LOOKS LIKELY.
FOR THE CURRENT SITUATION...A VERY WELL-DEFINED COLD FRONT IS
CLEARING THE FORECAST AREA EARLY THIS MORNING. ROBUSTLY WARM AIR
AHEAD OF THIS FEATURE HELPED CHICAGO BREAK THEIR RECORD WARM LOW
FOR YESTERDAY /54 DEGREES/. THE COMBINATION OF THE FRONTAL PASSAGE
AND RAIN TOOK TEMPERATURES DOWN AS MUCH AS 14 DEGREES IN ONE
HOUR AT SOME LOCATIONS. A GOOD PART OF THE SHOWER ACTIVITY IS
POST-FRONTAL...ASSOCIATED WITH ELEVATED MOISTURE TRANSPORT AND
STRONG CONVERGENCE ALONG THE BOUNDARY. ITS A GOOD THING A LOT OF
THIS IS POST FRONTAL...AS MORE SHOWER ACTIVITY AHEAD OF THE FRONT
COULD HAVE POTENTIALLY STEERED DOWN SOME OF THE 55 KT FLOW AT 1500
FT SEEN ON THE KLOT DOPPLER VELOCITY FOR HOURS AHEAD OF THE FRONT.
THE NORTHWEST WIND SPEEDS BEHIND THE FRONT ARE ACTUALLY QUITE A
BIT LOWER...GUSTING AT TIMES TO NEAR 25 MPH. THIS SHOULD CONTINUE
TO BE THE CASE INTO THIS AFTERNOON.
AN INTERESTING AREA OF ELEVATED CONVECTION IS SEEN IN NORTHERN MO
AS OF 300 AM HAVING ORIGINATED IN KS WITH A SHORT WAVE PER WATER
VAPOR ANALYSIS. THIS AREA CONTINUES TO GROW UPSCALE EAST
NORTHEAST...WELL BEHIND THE FRONT. RUC AND NAM CROSS SECTIONS
THROUGH THIS AREA SHOW STRONG MID-LEVEL FRONTOGENESIS AND A VERY
DEEP LAYER /AROUND 200 MB/ OF NEGATIVE EPV AND SLIGHTLY
DECREASING THETA-E...INDICATING CONVECTIVE INSTABILITY PRESENT.
THE RUC FORECAST FOR THE FORCING AND INSTABILITY...AND HRRR
PROJECTION OF REFLECTIVITY...SEEMS TO HAVE A STRONG HANDLE ON
THIS...WHILE MOST OTHER GUIDANCE DOES NOT. THIS AREA IS FORECAST
BY THE RUC/HRRR TO COME ACROSS THE SOUTHERN HALF OF THE FORECAST
AREA EARLY THIS MORNING. THE CONVECTIVE SIGNAL WEAKENS
SOMEWHAT...BUT STILL THINK ISOLATED TO SCATTERED THUNDER SHOULD BE
SEEN AT LEAST CLOSE IF NOT INTO THE SOUTHERN FORECAST AREA. THERE
COULD BE SOME SMALL HAIL WITH THIS GIVEN THE LOW WET BULB ZERO
VALUES. THIS SHOULD EXIT BY 10 AM TO NOON...WITH LINGERING CLOUDS
BEHIND THE FRONT ACROSS THE SOUTHERN AREA INTO EARLY TO MID
AFTERNOON.
COLD AIR ADVECTION BEHIND THE FRONT WILL UNDERCUT THE MORNING
CLOUDS AND SHOWERS IN THE SOUTH...HELPING TO KEEP TEMPERATURES
NEARLY STEADY OR EVEN CONTINUING TO FALL THROUGH MID-MORNING.
CLEARING BY LATE MORNING INTO AFTERNOON WILL ALLOW FOR SOME
REBOUND...BUT PROBABLY ONLY INTO THE LOWER TO MID 40S. CONFIDENCE
ON THE DEGREE OF RECOVERY IS SOMEWHAT LOW DUE TO WEIGHING THE COLD
AIR ADVECTION/CLOUD IMPACT THIS MORNING.
THE UPPER TROUGH OVER MN EARLY THIS MORNING WILL PASS OVER THE
GREAT LAKES AND BE RE-ENFORCED BY A STRONG JET MAX TO THE
NORTHWEST. THIS WILL HELP TO PUSH A SECONDARY COLD FRONT SOUTH
THROUGH THE AREA LATE THIS EVENING INTO OVERNIGHT. THIS LOOKS TO
REALLY SEND DEW POINTS DOWN AND POTENTIALLY TEMPERATURES FURTHER
TOO. THE COLD POCKET ASSOCIATED WITH THIS SHOULD DEVELOP SOME
STRATOCU TONIGHT ACROSS NORTHERN AND EASTERN AREAS THAT MAY
POTENTIALLY LINGER INTO FRI MORNING.
HIGH PRESSURE WILL THEN PREVAIL FRIDAY INTO EARLY SATURDAY...WITH
RETURN FLOW THEN SETTING UP FOR SATURDAY...WHICH SHOULD BE A
FAIRLY PLEASANT AND SUNNY DAY. THE WELL-ORGANIZED CLOSED UPPER
LOW OVER THE DESERT SOUTHWEST WILL DRIFT GRADUALLY NORTHEAST ON
SATURDAY...THEN BEGIN TO BECOME MORE NEUTRAL TO NEGATIVELY TILED
AS IT LIFTS OVER OUR AREA ON SUNDAY INTO SUNDAY NIGHT. THE
AMOUNT OF MOISTURE RETURN AHEAD OF THIS IS FAIRLY SHORT IN
DURATION...BUT IT CERTAINLY LOOKS TO BE DEEP ENOUGH AND WITHIN
STRONG ENOUGH ISENTROPIC LIFT FOR FAIRLY WIDESPREAD RAIN/SHOWERS
ON SUNDAY. HAVE CONTINUED TO INCH UP POPS. WHILE THE SYSTEM DRY
SLOT EVOLVES RIGHT INTO THE AREA...ELEVATED INSTABILITY IS VERY
MARGINAL DUE TO THE LIMITED DEGREE OF THETA-E RETURN. SO CONTINUE
WITH NO THUNDER MENTION...BUT COULD SEE SOME GUSTIER SHOWERS
POTENTIALLY SUNDAY AFTERNOON AND EVE IF THE GFS/EC PAN OUT AS IS.
SO HAVE MENTIONED MORE OF A SHOWER WORDING DURING THE AFTERNOON
AND EVE BECAUSE OF THIS. TEMPERATURES ON SUNDAY COULD ENCOMPASS A
FAIRLY LARGE RANGE THANKS TO THE IMPACTS OF THE LIKELY RAIN. WITH
CONFIDENCE INCREASING IN RAIN...HAVE CONTINUED NOT TO INCREASE
TEMPERATURES DESPITE SOME GUIDANCE INDICATING WARMER IN SUCCESSIVE
RUNS.
THE GFS REMAINS CONSISTENT WITH HAVING ANOTHER UPPER
WAVE...ACTUALLY ALMOST A PART OF THE FIRST ONE...MOVE NORTHEAST
ACROSS THE OHIO RIVER VALLEY ON MONDAY NIGHT INTO TUESDAY. THE
08.00 EC TRENDED BACK AWAY FROM THIS...BUT HAS BEEN THE LESS
CONSISTENT MODEL. HAVE KEPT POPS ON TUE MAINLY IN SOUTHEAST AREAS
TO ACCOUNT FOR THIS WAVE. WHILE THIS COULD HAVE IMPACTS ON
TEMPERATURES ON TUE...A LOW-LEVEL THERMAL TONGUE IS PROJECTED TO
BE KNOCKING ON OUR DOOR FROM THE WEST AND SHOULD PROVIDE FOR ABOVE
TO WELL ABOVE NORMAL TEMPERATURES. THE STRONGEST SIGNAL FOR VERY
MILD READINGS AND A DRY ATMOSPHERIC COLUMN IS ON WED AT THIS TIME.
AS PREVIOUS SHIFT DID...LEAN THE FORECAST TOWARDS THE BETTER
PERFORMING EC IN THOSE TYPE OF REGIMES. HIGHS IN THE UPPER 60S
INTO THE 70S ARE CURRENTLY WHAT THIS BLENDED APPROACH PRODUCES
AND SEEMS TO MAKE SENSE. WHILE A FRONT IS PRESENTLY FORECAST TO
MOVE THROUGH SOMETIME LATER WED INTO THU OF NEXT WEEK...IT WOULD
SEEM LIKELY WITH THE PATTERN THAT ABOVE NORMAL TEMPERATURES
CONTINUE THROUGH THE LATTER PART OF NEXT WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WINDS SHIFTING TO WEST NORTHWEST BETWEEN 08 AND 09 UTC TONIGHT
WITH FROPA.
* PERIODS OF SHOWERS AND THE POTENTIAL FOR A RUMBLE OF THUNDER
FOR A SHORT PERIOD THROUGH 09 UTC.
* MVFR/IFR CEILINGS POSSIBLE FOLLOWING THE FROPA.
KJB
//DISCUSSION...UPDATED 06Z...
SCATTERED SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF NORTHERN
ILLINOIS THIS EVENING. THIS ACTIVITY IS ASSOCIATED WITH A COLD
FRONT...WHICH IS CURRENTLY APPROACHING THE ROCKFORD AREA. THIS
FRONT WILL QUICKLY MOVE ACROSS ALL OF NORTHEASTERN ILLINOIS AND
NORTHWESTERN INDIANA OVERNIGHT TONIGHT. THE FRONTAL PASSAGE WILL
RESULT IN A WIND SWITCH OUT OF THE NORTHWEST OVER THE NEXT SEVERAL
HOURS.
SHOWERS AND POTENTIALLY A THUNDERSTORM WILL AFFECT THE TERMINALS FOR
A BRIEF PERIOD ALONG AND AHEAD OF THE FRONTAL ZONE. IT APPEARS
THAT THE BEST TIMING FOR CONVECTION WILL WITHIN THE NEXT HOUR OR
TWO AT KRFD...06-09 UTC FOR KORD AND KMDW AND 07 TO 10 UTC AT
KGYY. MUCH IF NOT ALL OF THE PRECIPITATION WILL END DURING THE
PREDAWN HOURS ON THURSDAY MORNING. ASIDE FROM THE POTENTIAL FOR A
BRIEF PERIOD OF LOW MVFR CIGS OR IFR CIGS AFTER THE FRONTAL
PASSAGE LATE TONIGHT...CIGS SHOULD QUICKLY REBOUND DURING THE
MORNING HOURS ON THURSDAY WITH VFR CONDITIONS EXPECTED TO QUICKLY
RETURN.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE WITH WIND SPEED/GUSTS AND DIRECTION...AND WITH
WIND SHIFT WITH FROPA.
* LOW TO MEDIUM CONFIDENCE WITH THUNDER TRENDS/TIMING.
* HIGH CONFIDENCE WITH MVFR CEILINGS TONIGHT AND MEDIUM CONFIDENCE
WITH A BRIEF PERIOD OF IFR CEILINGS LATER TONIGHT.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...VFR.
* SUNDAY AND MONDAY...CHANCE OF RAIN. MVFR POSSIBLE.
* TUESDAY...VFR.
KJB
&&
.MARINE...
150 PM CST
LOW PRESSURE CONTINUES TO MOVE ACROSS NORTHERN LAKE SUPERIOR WITH
ITS ASSOCIATED COLD FRONT EXTENDING SOUTHWARD INTO THE EASTERN U.P.
OF MICHIGAN AND EASTERN WISCONSIN. THE PRESSURE GRADIENT REMAINS
TIGHT ACROSS THE LAKE WITH SOUTHERLY GALES CONTINUING...ESPECIALLY
CLOSER TO THE LEE SHORE WHERE BETTER MIXING IS BEING ADVECTED OFF
THE LAND. THE LOW WILL DEEPEN THIS EVENING AS IT MOVES INTO WESTERN
QUEBEC WHICH WILL HELP FURTHER TIGHTEN THE GRADIENT ACROSS THE
NORTHERN PART OF THE LAKE AND AHEAD OF THE APPROACHING FRONT. THE
GRADIENT MAY RELAX JUST SLIGHTLY AHEAD OF THE FRONTAL TROUGH ACROSS
THE SOUTH HALF OF THE LAKE SO WINDS MAY EASE A BIT THIS EVENING
BEFORE THE FRONT PASSES. ONCE THE FRONT PASSES TONIGHT WINDS WILL
FLIP TO THE WEST THEN NORTHWEST WITH SPEEDS DIMINISHING AS THE LOW
LEVEL FLOW WEAKENS. SPEEDS ARE EXPECTED TO DROP BELOW GALES BY LATE
EVENING OR EARLY TONIGHT NORTH AND EARLY TONIGHT SOUTH THOUGH
GUSTS WILL PROBABLY REMAIN IN THE 20-25 KT RANGE IF NOT CLOSE TO
30 KT AT TIMES.
WINDS WILL SHIFT WESTERLY THURSDAY AS A WEAKER LOW DROPS
SOUTHEASTWARD ACROSS CENTRAL ONTARIO AND HIGH PRESSURE SPREADS
ACROSS THE NORTHERN PLAINS TOWARD THE UPPER MISSISSIPPI RIVER
VALLEY. UNSTABLE CONDITIONS WILL BE IN PLACE OVER THE LAKE RESULTING
IN DEEP MIXING AS THE PRESSURE GRADIENT TIGHTENS BETWEEN THESE TWO
SYSTEMS THURSDAY EVENING. EXPECT GUSTS TO 30 KT WITH POTENTIAL FOR
35 KT GALES AS WELL FOR AT LEAST A FEW HOURS. WINDS WILL DIMINISH
LATER FRIDAY AFTERNOON AS THE HIGH CRESTS THE LAKE BUT WINDS WILL
FLIP TO THE SOUTH AND QUICKLY RAMP UP FRIDAY NIGHT...ESPECIALLY
NORTH. WITH WARMER AIR MOVING BACK OVER THE LAKE STABILITY WILL
BECOME A CONCERN IN TERMS OF GUST POTENTIAL BUT MID RANGE GALES LOOK
POSSIBLE NORTH WITH SUB GALE FORCE WINDS EXPECTED SOUTH. SPEEDS
SHOULD EASE LATER SATURDAY WHILE REMAINING SOUTHERLY. LOW PRESSURE
WILL THEN LIFT ACROSS THE REGION SUNDAY NIGHT OR MONDAY MORNING BUT
THE TRACK IS NOT YET CLEAR SO CONFIDENCE IN WIND DIRECTION AND SPEED
IS LOW BY THIS TIME.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 4 AM THURSDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
453 AM EST THU MAR 8 2012
.SHORT TERM...
STRONG COLD FRONT WAS JUST COMING INTO FAR NW CWA AT 09Z AND WILL
QUICKLY MOVE ACROSS THE AREA TODAY. RADAR SHOWING AREA OF LIGHT TO
MODERATE SHOWERS ALONG AND BEHIND FRONT WITH SCATTERED SHOWERS OUT
AHEAD OF IT. SURFACE OBS SHOWING A GOOD 10 TO 15 DEGREE TEMP DROP
BEHIND FRONT WITH COLD AIR ADVECTION EXPECTED TO CONTINUE THROUGH
THE DAY WITH LITTLE RECOVERY IN TEMPS EXPECTED. HAVE TRIED TO TIME
FRONT THROUGH THE AREA WITH TEMPERATURE DROP AND PCPN TRENDS. VERY
DIFFICULT TO SAY THE LEAST AND ADJUSTMENTS WILL BE NECESSARY THROUGH
THE MORNING. REGIONAL RADAR MOSAIC AND SATELLITE ALSO SHOWING AN
AREA OF CONVECTION THAT HAS DEVELOPED OVERNIGHT IN OK AND KS AND IS
MOVING NORTHEAST. HRRR SEEMS TO BE ONLY MODEL TO HAVE A DECENT
HANDLE ON THIS WITH 04Z AND 05Z MODEL RUNS HAVING THIS WAVE COMING
INTO NW INDIANA AROUND 14Z. DISCUSSION WITH HPC SUGGEST 06Z RUN
TRENDING FARTHER EAST BUT GIVEN LOOKS OF RESPONSIBLE SHORT WAVE ON
WATER VAPOR AND RECENT RADAR MOSAIC TRENDS HAVE CONCERNS THAT THIS
MAY MOVE BACK INTO PART OF CENTRAL OR WEST CENTRAL CWA BY MID
MORNING. FOR THIS REASON HAVE SLOWED THE TREND OF CLEARING POPS
ACROSS THE AREA BY ABOUT 3 TO 5 HOURS TO ACCOUNT FOR THE POSSIBILITY
OF THIS RAIN MOVING BACK IN. BY AFTERNOON THIS WAVE LOOKS TO CLEAR
THE AREA AND RAPID DRYING BEGINS AND SHOULD SEE CLEARING SKIES.
ANOTHER FAST MOVING SHORT WAVE PASSES TO THE NORTH TONIGHT BUT
DRIVES SECONDARY COLD FRONT THROUGH. MAY SEE SOME INCREASE IN CLOUDS
NORTH WITH THIS WAVE AND LAKE PLUME AS DELTA T VALUES CLIMB INTO THE
TEENS. REMAINDER OF SHORT TERM FORECAST DRY WITH HIGH PRESSURE
MOVING IN FRIDAY NIGHT. THIS SHOULD ALLOW WINDS TO DECOUPLE AND
EXPECT GOOD RADIATIONAL COOLING BEFORE RETURN FLOW TRIES TO DEVELOP
LATE. HAVE LOWERED TEMPS FRIDAY NIGHT.
&&
.LONG TERM...
SATURDAY THROUGH WEDNESDAY...A LONG WAVE TROF WILL BECOME ENTRENCHED
ALONG THE WESTERN NORTH AMERICAN COAST WITH LARGE SCALE
AMPLIFICATION DOWNSTREAM OVER THE CENTRAL AND EASTERN CONUS. MUCH
WARMER AIR WILL RETURN TO THE AREA AND PERSIST THROUGH NEXT WEEK.
SHORT WAVE ENERGY WILL EJECT NORTHEAST AND PROVIDE A CHANCE FOR
SHOWERS THROUGH MOST OF THE PERIOD AS GULF MOISTURE SPREADS NORTH
ACROSS THE OHIO RIVER. THE GFS ENSEMBLE MEMBERS HAVE FINALLY COME
INTO REASONABLE AGREEMENT WITH ONE ANOTHER WITH MUCH SMALLER
STANDARD DEVIATIONS REFLECTED IN THE MEX MOS. THERE IS POTENTIAL
FOR HIGHS TO TOP 70 DEGREES DURING THE LATTER HALF OF THIS PERIOD.
HOWEVER...GIVEN THE POTENTIAL FOR CLOUDS AND RAINFALL...KEPT HIGHS
IN THE MID TO UPPER 60S TUESDAY/WEDNESDAY. ALSO...THERE IS AN
OUTSIDE CHANCE ONE OF THE SHORTWAVES MAY BE ABLE TO TAP A LITTLE
COOLER AIR AFTER THE SHORT WAVE PASSES.
&&
.AVIATION...
CONDITIONS TO DETERIORATE NEXT FEW HOURS AHEAD OF POTENT COLD FRONT.
THETA E ADVECTION ONGOING WITH MOISTURE POOLED ALONG FRONT. RADAR
SHOWING LARGE AREA OF SHOWERS MOVING TOWARD TAF SITES AND
SATELLITE/OBS INDICATE MVFR AND OCCASIONAL IFR CONDITIONS. CANNOT
RULE OUT VERY ISOLATED THUNDER SO LEFT CB MENTION IN. PCPN SHOULD
END FROM WEST TO EAST THURSDAY BEGINNING AROUND 12 TO 14Z AT KSBN
AND 15 TO 17Z AT KFWA. MVFR CLOUDS WILL LINGER AFTER FROPA BUT DRIER
AIR IN THE AFTERNOON SHOULD SCOUR THINGS OUT. A WEAK SHORT WAVE
TONIGHT COUPLED WITH FLOW DEVELOPING OFF LAKE MICHIGAN WITH DELTA T
VALUES IN LOWER TEENS SUGGEST POSSIBLE LAKE CLOUD DEVELOPMENT LATE
IN THE PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM EST FRIDAY FOR LMZ043-046.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS WICHITA KS
1210 AM CST THU MAR 8 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL AFFECT ALL
TERMINALS FOR THE NEXT FEW HOURS. LOW LEVEL DRY AIR WILL ARRIVE
FROM THE NORTH AND END PRECIPITATION BEFORE DAYBREAK IN CENTRAL
KS...AND AROUND DAYBREAK AT KICT/KHUT. PRECIPITATION WILL LIKELY
LINGER INTO THE MORNING AT KCNU. BRIEF PERIODS OF MVFR
CEILINGS/VISIBILITY ARE EXPECTED IN/NEAR PRECIPITATION. GUSTY
NORTH WINDS ARE EXPECTED DURING THE DAY GIVEN 45KTS AT 850MB AND
15-25KT IN BOUNDARY LAYER. -HOWERTON
&&
.PREV DISCUSSION... /ISSUED 536 PM CST WED MAR 7 2012/
UPDATE...
ADJUSTED THE SHORT TERM GRIDS TO BETTER REFLECT CURRENT OBSERVATIONS/
TRENDS. APPEARS THAT HRRR HAS BEST HANDLE ON FRONT/TIMING/TEMPERATURES
IN THE VERY SHORT TERM...WITH A BLEND INTO THE NAM LATER TONIGHT.
WILL LIKELY BE MAKING SOME TWEAKS TO POPS IN A BIT.
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MAIN AVIATION CONCERNS ARE POTENTIAL THUNDERSTORMS THIS EVENING
AND MVFR CEILINGS AT KCNU LATER TONIGHT. THERE APPEARS TO BE A
NARROW WINDOW OF OPPORTUNITY FOR ELEVATED STORMS TO DEVELOP THIS
EVENING AT KICT/KCNU AND POSSIBLY AS FAR NORTH AS KHUT. NAM/RUC
MODEL FORECAST HAS 500+ J/G MUCAPE ACROSS SOUTH CENTRAL/SOUTHEAST
KS ROUGHLY BETWEEN 03-08 UTC. CEILINGS WILL DECREASE IN THE RAIN AT
KCNU WITH MVFR CEILINGS LOOKING LIKELY OVERNIGHT. SOME IMPROVEMENT
IS ANTICIPATED ALL SITES DURING THE DAY. -HOWERTON
PREV DISCUSSION... /ISSUED 317 PM CST WED MAR 7 2012/
DISCUSSION...
MAIN FORECAST CONCERN IS THE PRECIPITATION CHANCES THIS EVENING AND
LATER THIS WEEK.
SYNOPSIS:
A POTENT UPPER LEVEL TROUGH IS MOVING EASTWARD ACROSS THE
INTER-MOUNTAIN WEST. AT THE SURFACE A COLD FRONT IS MAKING ITS WAY
ACROSS KANSAS. AS OF 3PM THE FRONT IS APPROACHING WICHITA WHICH IS A
LITTLE AHEAD OF WHAT WAS PREVIOUSLY THOUGHT. TEMPERATURES HAVE
SURGED AHEAD OF THE FRONT AIDED BY THE GUSTY SOUTHERLY WINDS.
TONIGHT - SATURDAY:
THE UPPER TROUGH THAT ENTERED THE GREAT BASIN YESTERDAY HAS
SPLIT...WITH THE CUT OFF PORTION LOCATED OVER NORTHERN
ARIZONA/SOUTHERN UTAH...AND MOVING SLOWLY THROUGH THE FOUR CORNERS
AREA. LEE CYCLOGENESIS HAS A SURFACE LOW CURRENTLY OVER NEW MEXICO
WITH THE SURFACE TROUGH FOLLOWING THE COLD FRONT THROUGH KANSAS TO
THE GREAT LAKES REGION. GUSTY SOUTH WINDS TODAY HAVE ADVECTED MID TO
UPPER 50 DEWPOINTS TO THE SOUTHEASTERN TWO-THIRDS OF THE CWA.
AS THIS COLD FRONT MOVES SOUTHEAST THROUGH THE AREA THIS
EVENING...SHOWERS AND SCATTERED THUNDERSTORMS ARE LIKELY MAINLY
ALONG AND BEHIND THE FRONT. THE LATEST GUIDANCE CONTINUES TO SHOW THAT
PRECIPITATION WILL DEVELOP BEYOND 00Z THIS EVENING MAINLY OVER
SOUTHEASTERN KANSAS. SUFFICIENT INSTABILITY AND SHEAR MAY
SUPPORT A FEW STRONGER STORMS AND HAIL WITH THOSE CELLS...ESPECIALLY
NEAR THE KANSAS/OKLAHOMA. NORTHERN EXTENT OF THE PRECIPITATION
APPEARS TO BE GREATER WITH THE NAM THAN THE OTHER MODELS...THINK THE
PRECIPITATION WILL RESIDE MAINLY OVER SOUTH CENTRAL AND SOUTHEASTERN
KANSAS BUT THERE REMAINS A SLIGHT CHANCE OVER CENTRAL KANSAS.
THE UPPER LEVEL LOW STALLS OVER THE TEXAS PANHANDLE FOR THURSDAY
THROUGH SATURDAY...AND WILL PUSH ANOTHER SURGE OF MOISTURE NORTH
THROUGHOUT THE DAY SATURDAY. ONCE AGAIN THE SOUTHEASTERN TWO-THIRDS
ARE MORE FAVORED FOR THE PRECIPITATION SATURDAY...BUT THIS WILL HAVE
TO BE MONITORED. PRECIP TYPE SHOULD STAY MOSTLY LIQUID FORM...BUT
SLIGHT CHANCE THAT SOME COULD BE FREEZING DRIZZLE ON THE NORTHERN
FRINGES.
LAUGEMAN
SUNDAY - WEDNESDAY:
THE CUT OFF UPPER LOW WILL BE KICKED EASTWARD BY THE NEXT UPPER
LEVEL WAVE MOVING INTO THE NORTHWEST. PRECIPITATION WILL BE
POSSIBLE SUNDAY MORNING AS THE UPPER LOW LIFTS OVER THE AREA...BUT
CHANCES DO NOT LOOK TO BE HIGH. THE SYSTEM WILL EXIT BY SUNDAY
NIGHT AND WHILE ANOTHER DISTURBANCE WILL LIFT OVER US...IT LOOKS TO
BE FAR ENOUGH EAST TO KEEP PRECIPITATION CHANCES AT BAY. WARM AIR
ADVECTION THROUGH THE BEGINNING OF THE WEEK WILL HELP TEMPERATURES
REACH WELL ABOVE NORMAL THROUGH THE PERIOD.
BILLINGS
FIRE WEATHER...
THE GRASSLAND FIRE DANGER INDEX REMAINS VERY HIGH THROUGH THE REST
OF THIS AFTERNOON WITH GUSTY SOUTHERLY WINDS AHEAD OF THE
FRONT...BUT AS THE WINDS DECREASE THIS EVENING CONDITIONS WILL
IMPROVE. BEHIND THE COLD FRONT WINDS WILL AGAIN BE GUSTY DURING THE
DAY THURSDAY AND VERY HIGH FIRE DANGER WILL AGAIN BE POSSIBLE ACROSS
PORTIONS OF CENTRAL KANSAS. OTHERWISE WITH THE CHANCES FOR
PRECIPITATION AND LIGHTER WINDS DURING THE WEEKEND THE FIRE DANGER
INDEX WILL MAX OUT IN THE HIGH CATEGORY.
BILLINGS
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE MAIN AVIATION CONCERN IS THE STRONG WINDS...COLD FRONT TIMING
AND MVFR CONDITIONS POSSIBLE THIS AFTERNOON AND OVERNIGHT.
THE COLD FRONT AS OF 18Z HAS JUST REACHED KSLN AND IT WILL
CONTINUE A SLOW SOUTHWARD TREK THIS AFTERNOON/EVENING. EXPECT IT
TO REACH KICT AFTER 00Z. AHEAD OF THE FRONT SOUTHERLY WINDS ARE
VERY STRONG WITH SUSTAINED SPEEDS BETWEEN 25-30 KTS AND GUSTS
UPWARDS TO 35-40 KTS. AS THE FRONT APPROACHES AND MOVES THROUGH
WINDS WILL DECREASE AND BECOME NORTHERLY. NORTHERLY WINDS WILL BE
GUSTY...BUT NOT AS STRONG AS AHEAD OF THE FRONT. CEILINGS ARE
BOUNCING AROUND THE MVFR/VFR THRESHOLD IN THE 2500-3500 FT RANGE
AHEAD AND BEHIND THE FRONT. HAVE REMAINED SOMEWHAT PESSIMISTIC
WITH THE TAF FORECAST IN MVFR.
PRECIPITATION CHANCES INCREASE AS THE FRONT MOVES INTO SOUTHERN
KANSAS BETWEEN 02-06Z WHERE MOISTURE IS MORE PLENTIFUL. HAVE -SHRA
AT KICT AND KCNU WHERE CONFIDENCE IS HIGHEST...WITH VCSH POSSIBLE
AT ALL OTHER TERMINALS EXCEPT KRSL. COLDER AIR IS EXPECTED TO PUSH
INTO CENTRAL KANSAS...BUT HAVE KEPT FREEZING PRECIPITATION OUT OF
THE FORECAST AT THIS TIME AS THAT IS FURTHER OUT IN THE FORECAST
AND CONFIDENCE ON THAT FEATURE IS LOW.
BILLINGS
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 34 53 39 50 / 20 10 30 50
HUTCHINSON 32 53 39 50 / 20 10 30 40
NEWTON 33 53 39 49 / 10 10 30 50
ELDORADO 33 53 39 50 / 10 10 20 50
WINFIELD-KWLD 35 52 40 50 / 20 10 30 50
RUSSELL 29 54 39 51 / 10 10 20 20
GREAT BEND 29 53 39 50 / 20 10 30 30
SALINA 30 55 38 51 / 10 10 20 40
MCPHERSON 31 54 39 50 / 10 10 20 40
COFFEYVILLE 37 54 40 51 / 20 10 20 50
CHANUTE 34 55 38 51 / 10 10 20 50
IOLA 33 54 37 50 / 10 10 20 50
PARSONS-KPPF 35 54 39 51 / 20 10 20 50
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1030 PM MST WED MAR 7 2012
.UPDATE...
ISSUED AT 1024 PM MST WED MAR 7 2012
CONVECTION HAS BROKEN OUT OVER THE PAST HOUR OR SO JUST SOUTHEAST
OF THE FORECAST AREA WITHIN AXIS OF 700MB THETA-E AND RIGHT REAR
QUAD OF UPPER JET. RUC SUGGESTING THAT MAIN ACTIVITY MAY CONTINUE
TO DEVELOP NORTHWARD POSSIBLY INTO SOUTHEAST GOVE AND WICHITA
COUNTIES FROM 06Z-08Z OR SO. RUC SOUNDINGS SUGGEST SNOW AS THE
MAIN PRECIP TYPE. HAVE UPDATED FORECAST TO REFLECT THE CHANCE OF
SNOW.
UPDATE ISSUED AT 752 PM MST WED MAR 7 2012
TONIGHT-THURSDAY NIGHT...18Z GFS/NAM/ECWMF AND MOST RECENT 00Z
NAM/RUC ALL SHOWING A MORE SOUTHERLY TRACK TO THE 500 LOW
CURRENTLY OVER EAST CENTRAL ARIZONA. 850-500 MOISTURE RATHER
LACKING TONIGHT EXCEPT ALONG THE HIGHER TERRAIN NEAR FLAGLER IN
EASTERN COLORADO BUT THAT WILL BE BRIEF AS IT CONTINUES TO MOVE
SOUTH AND OUT OF THE AREA. WILL NEED TO WATCH THE FAR
EAST/SOUTHEAST/SOUTH LATE TONIGHT AS RUC ONLY MODEL TO GENERATE
SOME LIGHT PRECIP AROUND 09Z DESPITE THE BETTER MOISTURE BEING
FURTHER SOUTH.
WITH THE MORE SOUTHERN TRACK MORE OF THE FORECAST AREA WILL SEE
PLENTIFUL SUNSHINE. WINDS WILL AGAIN BE FROM THE NORTH AT 15 TO 25
MPH. LATEST NAM/SREF 2M TEMPS AND MAV/MET MOS GUIDANCE ALL IN
AGREEMENT THAT AFTERNOON TEMPERATURES WILL PEAK GENERALLY IN THE
40S WITH A FEW 50S NEAR NORTON AND HILL CITY.
THURSDAY NIGHT...STILL LOOKS DRY. 00Z NAM TRIES TO INCREASE THE
LOW AND MID LEVEL MOISTURE ACROSS GREELEY AND WICHITA COUNTIES AS
THE UPPER LOW STARTS TO ROTATE INTO NORTHEAST NEW MEXICO/TEXAS
PANHANDLE. NOT MANY CHANGES MADE TO GRIDS DURING THIS PERIOD AT
PRESENT TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 212 PM MST WED MAR 7 2012
MAIN CONCERN WILL BE POSSIBILITY OF PRECIPITATION AND
PRECIPITATION TYPE. IN THE PAST 24 HRS...THERE HAS BEEN MUCH
UNCERTAINTY REGARDING PRECIP OVER THE AREA ASSOCIATED WITH THE
UPPER TROUGH WEST OF THE REGION...BUT THE GENERAL TREND HAS MADE
PRECIP LESS AND LESS LIKELY. BASED ON THIS TREND AND THE LATEST
GUIDANCE...HAVE LOWERED PROBABILITIES FURTHER...AND KEPT THE
HIGHEST CHANCES NEAREST TO THE TROUGH IN THE SOUTHWESTERN PART OF
THE AREA. NAM MODEL SOUNDINGS INDICATE THAT THERE IS STILL
POTENTIAL FOR A PERIOD OF FREEZING RAIN IN THE EARLY MORNING IF
ANY PRECIP WERE TO FALL...BUT SNOW SHOULD QUICKLY BECOME THE
PREDOMINANT PRECIP TYPE AS THE WESTERLY COMPONENT OF WINDS ALOFT
MODIFIES THE AIR MASS.
AS THE LOW MOVES FURTHER SOUTHEAST DURING THE DAYTIME ON
THURSDAY...THE CHANCE FOR PRECIP SHOULD MINIMIZE DURING THE
AFTERNOON HOURS. SKIES WILL CLEAR IN THE NORTHERN PORTION OF THE
AREA...ALLOWING WARMER TEMPERATURES IN THE NORTH COMPARED TO
FURTHER SOUTH. GUSTY NORTHERLY WINDS CAN BE EXPECTED DURING THE
DAYTIME DUE TO THE MOVEMENT AND POSITION OF THE TROUGH.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 212 PM MST WED MAR 7 2012
THERE ARE STILL SOME MODEL DIFFERENCES WITH THE UPPER LOW DURING
THIS TIMEFRAME. BOTH THE NAM/GFS BRING THE UPPER LOW INTO THE TEXAS
PANHANDLE THURSDAY NIGHT/FRIDAY. THE GFS HOLDS THE LOW IN THE TEXAS
PANHANDLE FRIDAY NIGHT WHILE THE NAM HAS IT POSITIONED A LITTLE
FURTHER NORTH IN THE OKLAHOMA PANHANDLE. BOTH HAVE THE GFS/NAM HAVE
THE UPPER LOW OVER THE OKLAHOMA PANHANDLE SATURDAY MORNING. THE GFS
TAKES THE LOW INTO CENTRAL KANSAS SATURDAY NIGHT. OTHER THAN
THURSDAY EVENING, LATE FRIDAY NIGHT AND SATURDAY BOTH MODELS KEEP
THE DYNAMICS/MOISTURE OUTSIDE OF THE FA. FOR THE PERIODS JUST
MENTIONED THERE IS SOME VERY MARGINAL MOISTURE OVER THE SOUTHEAST
FRINGE OF THE FA. FORECAST SOUNDINGS NEAR THE BEST PLAN VIEW
MOISTURE FIELD LOOK VERY DRY SO AM NOT OPTIMISTIC ABOUT ANY
MEASURABLE PRECIPITATION. FOR THIS REASON HAVE INCLUDED ONLY
SPRINKLES/FLURRIES THURSDAY EVENING AND LATE FRIDAY NIGHT. SOME
LIGHT RAIN MAY BE POSSIBLE IN THE FAR EAST SATURDAY MORNING.
OTHERWISE THE REMAINING PERIODS ARE DRY WITH NIL POPS.
MIN TEMPERATURES WILL MODERATE FROM THE LOWER 20S THURSDAY NIGHT TO
THE UPPER 20S/LOWER 30S FRIDAY/SATURDAY NIGHTS. MAX TEMPERATURES
WILL GENERALLY REACH THE MID 50S FRIDAY/SATURDAY.
FOR SUNDAY - WEDNESDAY...THE GFS SHOWS A RIDGE OVER THE FA SUNDAY
FOLLOWED BY WEST SOUTHWESTERLY FLOW MONDAY THROUGH WEDNESDAY.
LACK OF ANY SIGNIFICANT SHORTWAVE/FORCING WILL KEEP POPS NIL
THROUGH THIS PART OF THE FORECAST. 850MB TEMPERATURES INDICATE
THAT MAX TEMPERATURES SHOULD BE ABOUT 10 TO ALMOST 20 DEGREES
ABOVE NORMAL IN THE 60S TO AROUND 70. MIN TEMPERATURES IN THE
30S/LOW 40S WILL BE ABOUT 10 TO 15 DEGREES ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1024 PM MST WED MAR 7 2012
VFR THROUGH THE PERIOD AT BOTH KGLD AND KMCK. RAPID CLEARING
EXPECTED FROM NORTH TO SOUTH EARLY THURSDAY MORNING WITH ONLY A
FEW CIRRUS CLOUDS EXPECTED SHORTLY THEREAFTER. N WINDS OF 10 KTS
OR SO TO CONTINUE THROUGH 15Z THURSDAY THEN INCREASING INTO THE
15G25KT RANGE FROM 15Z-00Z AS HEATING/MIXING OCCUR. VRB06KTS
EXPECTED BY 01Z THROUGH THE REMAINDER OF THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...007
SHORT TERM...CJS
LONG TERM....FS
AVIATION...007
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
342 AM CST THU MAR 8 2012
.DISCUSSION...
Showers with embedded thunderstorm early this morning are continuing
to develop southwest of the area back into south central Kansas and
back into the OK and TX Panhandles in an area of mid level
frontogenetical forcing. These showers and thunderstorms have been
lifting northeastward into the forecast area where even weak
low-topped convection has been able to produce small hail with a
freezing level at 2kft.
These showers and thunderstorms will continue to be shunted to the
south this morning as a upper level trough moves from the Upper
Midwest into the Great Lakes region forcing the surface cold front,
which was the focus of this precipitation, further south and east
into the Ohio and Lower Mississippi River Valleys. Showers and
perhaps a isolated thunderstorms will continue this morning
occasionally mixing with sleet and snow perhaps evening changing
over to all snow, mainly along and south of the Missouri River and
will sink through the southern portion of the CWA by this afternoon.
As this system sinks south of the area high pressure will build into
the region from the Northern Plains tonight. This will allow for
calm winds and clear skies providing for good radiational cooling
and consequently dropped temperatures a degree or two for tonight.
High pressure will remain in control over the area on the day on
Saturday before shifting eastward into the Missouri River Valley on
Saturday night. It is then we turn our attention to our next system
of interest. This system is in the form of a closed low across the
southwestern CONUS. Models are in good agreement that this system
will pull out of the Southwest into the Southern Plains on Saturday
night. Out ahead of the system Gulf moisture will be drawn northward
under a good WAA regime. Model QPF fields spread showers across the
area by Saturday night which continues into Sunday. Models differ on
the timing the upper level system rotates through the area ranging
anywhere from the faster GFS which brings it through on Sunday night
to the slower GEM which brings it through Monday night so did not
change much to the initialization to capture the myriad of timing
scenarios. One caveat of interest in the model analysis is that the
EC as it brings the system out of the Southwest into the Plains it
open up the cut off low and begins to take on a negative tilt. If,
this scenario does come to fruition it will provide for more
unstable conditions than the other model solutions and thunderstorms
possibly severe will be possible. However since the EC is the only
model advertising this solution have opted to keep precipitation
wording to just rain at the moment.
Otherwise, for the beginning of the work week expect well above
average conditions with downsloping westerly flow aloft and southern
flow at the surface. Highs on Monday will be in the mid to upper 60s
giving way to lower 70s on Tuesday and Wednesday.
73
&&
.AVIATION...
For the 06Z TAFs...Have made significant changes to the first 6
hours of the TAFs to reflect the rapid development of elevated
convection from southwest into north central KS since 04z. Latest
short range model trends from the HRRR, RUC and NAM spread this
convective activity northeastward and into the terminals shortly
after midnight. A combination of isentropic ascent on the 300K
surface, the right entrance region of a departing upper level jet
streak and layered frontogenesis are working in concert to aid the
convective development. Am expecting to see the rain and clod cover
shift south after sunrise Thursday with VFR conditions quickly
moving into the terminals.
While thunder was not put into the forecast will need to monitor
evolution of upstream convection and make any necessary short term
adjustments.
MJ
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
332 AM CST THU MAR 8 2012
.SHORT TERM...
ISSUED AT 316 AM CST THU MAR 8 2012
(TODAY AND TONIGHT)
COLD FRONT HAS MOVED ABOUT HALFWAY THROUGH THE CWA AND IS CURRENTLY
ENTERING THE NORTHWESTERN PART OF THE ST. LOUIS METRO AREA. SHOWERS
AND SCATTERED THUNDERSTORMS HAVE DEVELOPED ALONG AND AHEAD OF THE
FRONT IN A BROAD AREA OF 950-850MB MOISTURE CONVERGENCE. THIS
MOISTURE CONVERGENCE IS COINCIDENT WITH LARGE SCALE ASCENT FROM
MID-LEVEL CURRENTLY PASSING THROUGH THE UPPER MIDWEST. A SECOND
LARGER AREA OF PRECIPITATION IS MOVING ACROSS WESTERN MISSOURI WHICH
IS BEING GENERATED BY THE LARGE SCALE ASCENT ON THE TAIL END OF THE
TROUGH AND A LITTLE STRONGER LOW LEVEL CONVERGENCE ON THE NOSE OF A
50KT LOW LEVEL JET OVER THE PLAINS. THIS FORCING WILL CONSOLIDATE
THROUGH THE MORNING PER THE RUC AS THE LOW LEVEL JET VEERS WITH
TIME. THIS SHOULD BE ENOUGH TO KEEP LIKELY OR CATEGORICAL RAIN
CHANCES GOING FOR ABOUT THE SOUTHERN TWO-THIRDS OF THE CWA EARLY
THIS MORNING...WITH A GRADUAL DIMINISHING TREND THROUGH THE DAY AS
THE FORCING PUSHES SOUTH AND EAST. THERE SHOULD BE ENOUGH
INSTABILITY TO KEEP AT LEAST A MENTION OF SCATTERED THUNDERSTORMS
THIS MORNING ALONG AND AHEAD OF THE 850MB COLD FRONT. CAN`T RULE
OUT THE POTENTIAL FOR SOME SNOW OR SLEET ON THE NORTHERN FRINGE OF
THE PRECIPITATION WHERE RUC SOUNDINGS ARE SHOWING THE LOW LEVEL
THERMAL PROFILES COOLING NEAR 0C ABOUT THE TIME THAT THE
PRECIPITATION ENDS. THINK THIS WILL BE A SHORT LIVED EVENT AND
MAINLY FOUND WHERE CONVECTION IS MORE CONCENTRATED. TONIGHT SHOULD
BE DRY AS SUBSIDENCE SETS IN BEHIND THE NORTHERN STREAM TROUGH.
TEMPERATURES SHOULD REMAIN STEADY OR SLOWLY FALL THROUGH THE DAY
OVER THE SOUTHERN HALF OF THE CWA EXTENSIVE CLOUD COVER AND DECENT
COLD AIR ADVECTION BEHIND THE FRONT. GFS MOS TEMPERATURES LOOK A
BIT TOO WARM TONIGHT GIVEN THE MAINLY CLEAR SKIES AND WINDS
TURNING LIGHT AS THE SURFACE RIDGE SETTLES INTO THE AREA.
BRITT
&&
.LONG TERM...
ISSUED AT 330 AM CST THU MAR 8 2012
(FRIDAY THROUGH NEXT WEDNESDAY)
SFC HIGH BUILDS IN BEHIND THE DEPARTING CDFNT ON FRI WITH DRY WX
EXPECTED ON FRI AND MOST OF SAT BEFORE ANOTHER ROUND OF PCPN DVLPS
ON SAT NIGHT AS AN UPPER LOW OVER AZ/NM BEGINS LIFTING NEWD THROUGH
THE CENTRAL CONUS. MODELS CONTINUE TO STRUGGLE WITH HOW AND WHEN
THIS LOW LIFTS NEWD. THE PREVIOUS FOUR RUNS OF THE ECMWF WERE
EVENLY SPLIT BETWEEN KEEPING THE VORT CENTER INTACT /00Z RUNS ON
MARCH 7TH AND 8TH/ AND SPLITTING IT INTO TWO VORT MAXES /12Z RUNS ON
MARCH 6TH AND 7TH...SIMILAR TO WHAT THE GFS HAS BEEN DEPICTING FOR
THE LAST SEVERAL DAYS/. 08/00Z GEM REMAINS SIMILAR TO THE 07/00Z
RUN AND SHOWS THE LOW RETROGRADING TO BAJA CA THEN MOVING THROUGH
MEXICO BEFORE LIFTING THROUGH TX AND INTO NWRN MO. THESE LARGE
DIFFERENCES BETWEEN THE 3 MODELS APPEAR TO STEM FROM DIFFERENT
HANDLING OF THE INTERACTION BETWEEN THE CLOSED LOW AND A SUBTLE
AREA OF ENHANCED VORTICITY THAT SHOULD BE MOVING THROUGH ID/NV AT
08/12Z. DESPITE THE DIFFERENT DETAILS...MODEL SOLUTIONS ALL
SUGGEST ANOTHER ROUND OF PCPN SOMEWHERE BETWEEN SAT NIGHT AND MON
AS THE CLOSED LOW /OR ITS REMNANTS/ FINALLY LIFTS NEWD. WAA SHRA
EXPECTED TO DVLP FIRST FOLLOWED BY AN INCREASE IN PCPN COVERAGE AS
LARGE SCALE LIFT INCREASES WITH THE APPROACHING VORT MAX. MODELS
ARE OFTEN TOO QUICK TO BRING A CLOSED LOW BACK INTO THE PREVAILING
FLOW THEREFORE I WOULD NOT BE SURPRISED IF THIS OVERALL FCST
SCENARIO ENDS UP BEING DELAYED BY A DAY OR SO AS THE MODELS CATCH
UP TO THE ATMOSPHERE.
KANOFSKY
&&
.AVIATION...
ISSUED AT 1057 PM CST WED MAR 7 2012
COLD FRONT CONTINUES TO PUSH EAST AT A STEADY PACE AND JUST MOVED
THROUGH UIN OVER THE LAST 30 MINUTES. LEADING EDGE OF NARROW BAND
OF SHOWERS/ISOLATED THUNDERSTORMS DENOTES FRONT AND EXTRAPOLATION
OF THIS ECHO MASS INDICATES IT SHOULD PUSH THROUGH COU BETWEEN
06-07Z. LONGER EXTRAPOLATION OF RADAR IMAGERY...AS WELL AS SURFACE
COLD FRONTAL POSITIONS DURING THE EVENING...STILL INDICATE
ARRIVAL OF COLD FRONT IN STL AREA 10-11Z TIME FRAME. THUNDERSTORMS
HAVE BEEN INCREASING IN COVERAGE OVER THE PAST FEW HOURS IN THE
BEST INSTABILITY AXIS OVER WESTERN MISSOURI...AND BASED ON 00Z
GUIDANCE THAT SUGGESTS INSTABILITY WILL PERSIST INTO THE PREDAWN
HOURS THINK THAT THIS NARROW LINE OF STORMS WILL BE ABLE TO HOLD
TOGETHER AS IT WORKS EAST INTO EASTERN MO AND THE STL AREA. POST
FRONTAL PRECIP HAS EXPANDED OVER IA BUT SO FAR AS REMAINED VERY
LIMITED OVER MO...BUT THINK THIS WILL BE CHANGING OVERNIGHT AS
SHORTWAVE DIGS INTO REGION AND ENHANCES LARGE SCALE UVV IN THE
COLDER AIR. STILL LOOKS LIKE FROPA WILL BRING MVFR CIGS TO EACH
TAF LOCATION...AND WHILE WE`RE NOT SEEING ANY WIDESPREAD IFR
BEHIND THE FRONT ATTM WE`LL CERTAINLY HAVE TO CAREFULLY MONITOR
CONDITIONS OVERNIGHT DUE TO THIS THREAT.
SPECIFICS FOR KSTL...
COLD FRONT STILL EXPECTED TO ARRIVE AROUND 10Z WITH A NARROW LINE
OF THUNDERSTORMS. IMMEDIATELY BEHIND THE FRONT CONDITIONS SHOULD
QUICKLY DROP TO MVFR WITH CIGS BTWN 1-3 KFT AND VSBYS 3-5SM IN
LIGHT RAIN/FOG. 00Z DATA SUPPORTS EARLIER THINKING THAT DRIER AIR
WELL BEHIND THE FRONT SHOULD BEGIN TO IMPROVE CONDITIONS DURING
THE LATE MORNING...WITH MVFR CIGS MOVING OUT OF THE AREA AROUND
MIDDAY.
TRUETT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
319 AM CST THU MAR 8 2012
.SHORT TERM...
ISSUED AT 316 AM CST THU MAR 8 2012
(TODAY AND TONIGHT)
COLD FRONT HAS MOVED ABOUT HALFWAY THROUGH THE CWA AND IS CURRENTLY
ENTERING THE NORTHWESTERN PART OF THE ST. LOUIS METRO AREA. SHOWERS
AND SCATTERED THUNDERSTORMS HAVE DEVELOPED ALONG AND AHEAD OF THE
FRONT IN A BROAD AREA OF 950-850MB MOISTURE CONVERGENCE. THIS
MOISTURE CONVERGENCE IS COINCIDENT WITH LARGE SCALE ASCENT FROM
MID-LEVEL CURRENTLY PASSING THROUGH THE UPPER MIDWEST. A SECOND
LARGER AREA OF PRECIPITATION IS MOVING ACROSS WESTERN MISSOURI WHICH
IS BEING GENERATED BY THE LARGE SCALE ASCENT ON THE TAIL END OF THE
TROUGH AND A LITTLE STRONGER LOW LEVEL CONVERGENCE ON THE NOSE OF A
50KT LOW LEVEL JET OVER THE PLAINS. THIS FORCING WILL CONSOLIDATE
THROUGH THE MORNING PER THE RUC AS THE LOW LEVEL JET VEERS WITH
TIME. THIS SHOULD BE ENOUGH TO KEEP LIKELY OR CATEGORICAL RAIN
CHANCES GOING FOR ABOUT THE SOUTHERN TWO-THIRDS OF THE CWA EARLY
THIS MORNING...WITH A GRADUAL DIMINISHING TREND THROUGH THE DAY AS
THE FORCING PUSHES SOUTH AND EAST. THERE SHOULD BE ENOUGH
INSTABILITY TO KEEP AT LEAST A MENTION OF SCATTERED THUNDERSTORMS
THIS MORNING ALONG AND AHEAD OF THE 850MB COLD FRONT. CAN`T RULE
OUT THE POTENTIAL FOR SOME SNOW OR SLEET ON THE NORTHERN FRINGE OF
THE PRECIPITATION WHERE RUC SOUNDINGS ARE SHOWING THE LOW LEVEL
THERMAL PROFILES COOLING NEAR 0C ABOUT THE TIME THAT THE
PRECIPITATION ENDS. THINK THIS WILL BE A SHORT LIVED EVENT AND
MAINLY FOUND WHERE CONVECTION IS MORE CONCENTRATED. TONIGHT SHOULD
BE DRY AS SUBSIDENCE SETS IN BEHIND THE NORTHERN STREAM TROUGH.
TEMPERATURES SHOULD REMAIN STEADY OR SLOWLY FALL THROUGH THE DAY
OVER THE SOUTHERN HALF OF THE CWA EXTENSIVE CLOUD COVER AND DECENT
COLD AIR ADVECTION BEHIND THE FRONT. GFS MOS TEMPERATURES LOOK A
BIT TOO WARM TONIGHT GIVEN THE MAINLY CLEAR SKIES AND WINDS
TURNING LIGHT AS THE SURFACE RIDGE SETTLES INTO THE AREA.
BRITT
&&
.LONG TERM...
ISSUED AT 300 PM CST WED MAR 7 2012
(THURSDAY THROUGH WEDNESDAY)
COLD FRONT SHOULD MAKE IT TO THE STL METRO AREA BY 12Z THU WITH A
BAND OF SHOWERS AND STORMS EXPECTED ALONG AND JUST BEHIND THE
FRONT. THE BEST CHANCE OF RAIN ON THU WILL BE S AND E OF STL AS THE
FRONT CONTINUES TO DROP SEWD THROUGH THE AREA. A SURFACE RIDGE
WILL BUILD SEWD INTO OUR AREA BEHIND THE FRONT WITH COLDER AND
DRIER AIR FILTERING INTO THE REGION. WITH RELATIVELY STRONG CAA
BEHIND THE SFC/850 MB FRONT AREAS WHICH REMAIN CLOUDY ON THU MAY
SEE LITTLE IF ANY DIURNAL RISE IN TEMPERATURES. MOST OF THIS RAIN
SHOULD PUSH SOUTH OF OUR AREA BY THU EVNG WITH CLEARING FROM N-NW
TO S-SE AND COLDER TEMPERATURES THU NGT. TRANQUIL...DRY WEATHER WITH
NEAR NORMAL TEMPERATURES FOR FRI AND FRI NGT...THEN INCREASING
CLOUDINESS ON SAT AS A SLOW MOVING CLOSED...UPPER LEVEL LOW NOW
OVER NRN AZ MOVES THROUGH THE PLAINS AND APPROACHES MO. THE NAM
MODEL IS A LITTLE QUICKER BRINGING SHOWERS INTO OUR AREA THIS
WEEKEND AHEAD OF THIS UPPER LOW. FOR NOW WILL FOLLOW CLOSER TO THE
GFS AND ECMWF MODELS SOLUTION WHICH BRING MOST OF THE RAIN
THROUGH OUR FORECAST AREA SAT NGT AND SUN. MOST OF THE RAIN SHOULD
SHIFT E OF OUR AREA BY SUN NGT...ALTHOUGH COULD NOT RULE OUT SOME
LIGHT RAIN MAINLY OVER W CNTRL IL UNDERNEATH OR NEAR THE UPPER
LOW CENTER. AFTER A BRIEF BREAK IN THE RAIN BOTH THE GFS AND ECMWF
MODELS ARE BRINGING ANOTHER SHOT OF RAIN...MAINLY TO THE SRN AND
ERN PORTIONS OF OUR AREA MON AFTN AND MON NGT AHEAD OF A SRN
STREAM UPPER LEVEL TROUGH WHICH WILL MOVE NEWD INTO SERN MO BY MON
EVNG. ALTHOUGH THE GFS MODEL TRIES TO BRING A WEAK COLD FRONT
SEWD INTO OUR AREA TUE NGT...THE ECMWF MODEL IS WARMER WITH
CONTINUING S-SWLY LOW LEVEL FLOW BRINGING THE 16 DEGREE C 850 MB
ISOTHERM NEWD INTO MO ON WED WITH HIGH TEMPERATURES IN THE 70S
LIKELY IF THIS SCENERIO VERIFIES.
GKS
&&
.AVIATION...
ISSUED AT 1057 PM CST WED MAR 7 2012
COLD FRONT CONTINUES TO PUSH EAST AT A STEADY PACE AND JUST MOVED
THROUGH UIN OVER THE LAST 30 MINUTES. LEADING EDGE OF NARROW BAND
OF SHOWERS/ISOLATED THUNDERSTORMS DENOTES FRONT AND EXTRAPOLATION
OF THIS ECHO MASS INDICATES IT SHOULD PUSH THROUGH COU BETWEEN
06-07Z. LONGER EXTRAPOLATION OF RADAR IMAGERY...AS WELL AS SURFACE
COLD FRONTAL POSITIONS DURING THE EVENING...STILL INDICATE
ARRIVAL OF COLD FRONT IN STL AREA 10-11Z TIME FRAME. THUNDERSTORMS
HAVE BEEN INCREASING IN COVERAGE OVER THE PAST FEW HOURS IN THE
BEST INSTABILITY AXIS OVER WESTERN MISSOURI...AND BASED ON 00Z
GUIDANCE THAT SUGGESTS INSTABILITY WILL PERSIST INTO THE PREDAWN
HOURS THINK THAT THIS NARROW LINE OF STORMS WILL BE ABLE TO HOLD
TOGETHER AS IT WORKS EAST INTO EASTERN MO AND THE STL AREA. POST
FRONTAL PRECIP HAS EXPANDED OVER IA BUT SO FAR AS REMAINED VERY
LIMITED OVER MO...BUT THINK THIS WILL BE CHANGING OVERNIGHT AS
SHORTWAVE DIGS INTO REGION AND ENHANCES LARGE SCALE UVV IN THE
COLDER AIR. STILL LOOKS LIKE FROPA WILL BRING MVFR CIGS TO EACH
TAF LOCATION...AND WHILE WE`RE NOT SEEING ANY WIDESPREAD IFR
BEHIND THE FRONT ATTM WE`LL CERTAINLY HAVE TO CAREFULLY MONITOR
CONDITIONS OVERNIGHT DUE TO THIS THREAT.
SPECIFICS FOR KSTL...
COLD FRONT STILL EXPECTED TO ARRIVE AROUND 10Z WITH A NARROW LINE
OF THUNDERSTORMS. IMMEDIATELY BEHIND THE FRONT CONDITIONS SHOULD
QUICKLY DROP TO MVFR WITH CIGS BTWN 1-3 KFT AND VSBYS 3-5SM IN
LIGHT RAIN/FOG. 00Z DATA SUPPORTS EARLIER THINKING THAT DRIER AIR
WELL BEHIND THE FRONT SHOULD BEGIN TO IMPROVE CONDITIONS DURING
THE LATE MORNING...WITH MVFR CIGS MOVING OUT OF THE AREA AROUND
MIDDAY.
TRUETT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1154 PM CST WED MAR 7 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Convection finally got going along the cold front. However, the
activity is rather narrow, but intense. Not expecting any severe.
Cold front with the attendant convection will spread gradually east
across the sern 1/4 of the CWA. In the post frontal regime a number
of short range models including the latest runs from the HRRR, RUC
and NAM all blossom convection across south central into east
central KS after 06z, spreading into west central MO and the
southern half of the CWA after 09z. This appears to be a reflection
of the right rear entrance region of the 250mb jet segment
interacting with layered frontogenesis from 850mb to 650mb. Given
the model consensus on spreading rain further north have increased
and adjusted pops further north after midnight.
MJ
&&
.PREV DISCUSSION...
/342 PM CST Wed Mar 7 2012/
An advancing cold front pushed into far northwest Missouri, and
adjacent areas of extreme northeast Kansas, early this afternoon.
This has brought some relief to those areas from the strong and
gusty winds that persisted overnight and into today. Cloud cover in
advance of the front has decreased the wind gusts farther south and
east also, so while there is no grantee that any break in the clouds
would not result in quick round of momentum transfer in the boundary
layer, it looks unlikely at this time. So, have opted to drop the
remainder of the wind advisory from west central Kansas through
central Missouri under a a little early. After the frontal passage
this evening, winds will turn to the northwest, remaining a bit gusty
through the overnight hours into Thursday.
Focusing on the front for tonight, radar returns and occasional
surface observations indicate that showers are beginning to develop
along and just behind it, across northwest Missouri and eastern
Kansas. This expected activity will continue to ramp up as we move
through the later afternoon and evening hours as modest isentropic
assent is supplemented, and then supplanted, with moderate to strong
frontogenic forcing in the post frontal environment. This, coupled
with some moderate lapse rates that will still be present aloft as
the front shifts through, should allow some embedded thunderstorm
activity just behind the front this evening. Severe thunderstorm
activity is not expected as there looks to be insufficient
instability to fuel anything more than your average embedded
thunderstorm.
Showers, and some isolated thunder, may still be lingering across
areas from east central Kansas into central Missouri Thursday morning
and into the afternoon hours. With the passage of the cold front
tonight, a modest dome of cool air will slide across the Lower
Missouri River Valley Thursday into Friday, knocking our temperatures
back down from the mid spring like temperatures we have enjoyed over
the past few days. Thursday will be the coolest day with highs in the
40s to near 50, with Friday warming into the 50s across the whole
forecast areas.
Cutter
Medium Range (Saturday-Tuesday)...
Model consistency continues to be the primary forecast concern as we
head through the initial stages of the medium range. Some progress
has been made with GFS/ECMWF solutions in the depth of upper low
trapped under broad ridging as it crosses the region. However the
exact track of this low remains in doubt and will have significant
implications on local conditions especially on Sunday. GEFS signals
this disagreement well with two clusters of solutions. One clusters
the more westerly ECMWF and the other cluster favors the progressive
easterly solution of the GFS. Nevertheless, it does appear that
broad warm advection will spread northward and into the area late
Saturday and into Sunday. Currently favored areas for more
widespread rain are focused on the eastern half of Missouri, with
uncertainty on positioning of dry slot leading to lower certainty in
western zones. Given the degree of warm advection, wouldn`t be
surprised to see a bit of thunder, but confidence too low to
introduce at this time. Have not trimmed much off the populated POPs
for Sunday night given uncertainty of where cold core of upper low
may pass.
Heading into next week, rising mid-level heights will give credence
to another substantial warm up looks in store for the area as we
move into Tuesday and Wednesday. Southwesterly low level flow
combined with 850mb temps +12 to +16 would feature lower to middle
70s. Have bumped overnight lows and max temps. Just food for
thought beyond the medium range as we look for additional chances of
snow this winter, continual NAEFS ensemble runs as well as guidance
from CPC place very high probabilities of above normal temperatures
continuing through the 8-14 day period with a continuation of
westerly to southwesterly flow aloft.
Dux
&&
.AVIATION...
For the 06Z TAFs...Have made significant changes to the first 6
hours of the TAFs to reflect the rapid development of elevated
convection from southwest into north central KS since 04z. Latest
short range model trends from the HRRR, RUC and NAM spread this
convective activity northeastward and into the terminals shortly
after midnight. A combination of isentropic ascent on the 300K
surface, the right entrance region of a departing upper level jet
streak and layered frontogenesis are working in concert to aid the
convective development. Am expecting to see the rain and clod cover
shift south after sunrise Thursday with VFR conditions quickly
moving into the terminals.
While thunder was not put into the forecast will need to monitor
evolution of upstream convection and make any necessary short term
adjustments.
MJ
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1148 PM CST WED MAR 7 2012
.UPDATE...RADAR DATA FROM KUEX...AS WELL AS MULTIPLE SITES ACROSS
KANSAS...INDICATE ELEVATED CONVECTION RAPIDLY SPREADING IN AERIAL
COVERAGE ACROSS CENTRAL AND EASTERN KANSAS. RUC ANALYSIS AND LAPS
DATA INDICATE AN AXIS OF ENHANCED THERMAL ADVECTION FROM JUST
ABOVE 850MB TO NEAR 700MB...WITH RESULTANT ISENTROPIC UPGLIDE AND
SATURATION EVIDENT ALONG THE 305K SURFACE. PROXIMITY
SOUNDINGS...ALSO FROM RUC ANALYSIS AND LAPS DATA...ACROSS OUR SOUTHERN
CWA AND POINTS FARTHER SOUTH ACROSS CENTRAL KANSAS INDICATE THIS
CONVECTION IS ROOTED TO AROUND 700MB...WHERE MINIMAL CIN IS
EVIDENT AND CAPE VALUES AS HIGH AS 300J/KG ALSO EXIST. SHORT TERM
GUIDANCE SUGGESTS THIS AXIS OF MID LEVEL THERMAL ADVECTION WILL
CONTINUE MOVING EAST THROUGH THE OVERNIGHT HOURS...THUS CARRYING
CHANCES FOR CONVECTION WITH IT INTO EASTERN KANSAS AND WESTERN
MISSOURI. THAT BEING SAID...BASED ON THE CURRENT TRAJECTORIES OF
ONGOING CONVECTION ACROSS CENTRAL KANSAS...THERE IS A CHANCE SOME
OF THIS ACTIVITY WILL CLIP EXTREME SOUTHEASTERN PORTIONS OF OUR
CWA. WENT AHEAD AND UPDATED THE FORECAST AND HWO TO INCLUDE
THUNDER MENTION FOR PORTIONS OF OSBORNE AND MITCHELL COUNTIES AS A
RESULT.
&&
.PREV DISCUSSION... /ISSUED 1044 PM CST WED MAR 7 2012/
AVIATION...06Z TAF. VFR CONDITIONS ARE EXPECTED THROUGH THE TAF
PERIOD. DRY AIR CONTINUES TO ADVECT SOUTH TONIGHT AND SKIES ARE
GRADUALLY CLEARING. WINDS WILL BE FAIRLY LIGHT TONIGHT...BUT WILL
INCREASE FM THE NORTHWEST THURSDAY MORNING...BEFORE TRANSITIONING
WESTERLY AND DECREASING AGAIN THURS EVENING.
PREV DISCUSSION... /ISSUED 335 PM CST WED MAR 7 2012/
SHORT TERM...THROUGH 00Z FRIDAY...THE FRONTAL BOUNDARY THAT
BROUGHT BREEZY NORTHERLY WINDS AND MUCH COLDER TEMPERATURES TO THE
REGION TODAY IS PRESENTLY DRAPED FROM SOUTHEASTERN NEBRASKA TO THE
PANHANDLE OF OKLAHOMA/TEXAS. WHILE SOME MODERATE INSTABILITY AND
POTENTIAL FOR SHOWER DEVELOPMENT IS EVIDENT ALONG AND JUST AHEAD
OF THIS BOUNDARY...LATEST MODEL GUIDANCE CONTINUES TO SUGGEST THE
BOUNDARY WILL SLOWLY SINK SOUTHEASTWARD OVERNIGHT... DIMINISHING
ANY CHANCES FOR MEASURABLE PRECIPITATION ACROSS THE LOCAL AREA. AS
A RESULT...WENT AHEAD AND TRIMMED BACK ANY MENTION OF PRECIP
OVERNIGHT. ADDITIONALLY....WITH SLOWLY CLEARING SKIES APPROACHING
FROM THE NORTHWEST AND DIMINISHING WINDS EXPECTED OVERNIGHT AS AN
AREA OF SURFACE HIGH PRESSURE TRANSITIONS CLOSER TOWARDS THE LOCAL
AREA FROM THE HIGH PLAINS...WENT AHEAD AND TWEAKED OVERNIGHT
TEMPERATURES DOWN A BIT...ALBEIT THEY REMAIN RIGHT AROUND
CLIMATOLOGY FOR THIS TIME OF YEAR.
FOR THURSDAY...LIGHT NORTHERLY WINDS WILL BE PREVALENT ACROSS THE
REGION AS THE AFOREMENTIONED AREA OF SURFACE HIGH PRESSURE
SETTLES IN ACROSS THE STATE OF NEBRASKA. THIS WILL ALLOW FOR
CLEARING SKIES AS A GENERALLY PLEASANT DAY ACROSS THE
REGION...WITH AFTERNOON TEMPERATURES REBOUNDING A FEW DEGREES FROM
THIS AFTERNOONS READINGS...WITH EXPECTED HIGH TEMPERATURES IN THE
LOWER 50S MOST LOCATIONS...WHICH REMAINS APPROXIMATELY 5 DEGREES
ABOVE SEASONAL NORMALS FOR THIS TIME OF YEAR.
LONG TERM...00Z FRIDAY THROUGH WEDNESDAY. PRIMARY FORECAST
CONCERNS ARE WITH TEMPERATURES...AND WEEKEND PRECIPITATION
CHANCES.
MODELS IN PRETTY GOOD AGREEMENT AT THE START OF THE LONG TERM
PERIOD...THROUGH FRIDAY NIGHT...AND THE FORECAST REMAINS DRY. UPPER
LEVEL PATTERN SHOWS NORTHWESTERLY FLOW ACROSS THE REGION...SITTING
BETWEEN A TROUGH AXIS SWINGING THROUGH THE GREAT LAKES/MIDWEST...AND
A SLOW MOVING CLOSED OFF UPPER LEVEL LOW PRESSURE SYSTEMS OVER NEW
MEXICO. THROUGH THE DAYTIME ON FRIDAY AND EVEN FRIDAY NIGHT...NOT A
LOW OF PROGRESS IS MADE BY THE LOW...WITH MODELS REMAINING IN PRETTY
GOOD AGREEMENT SHOWING A SECOND LOW DEVELOPING TO THE SOUTHWEST /NRN
BAJA/ OF THE ORIGINAL...WHICH BY 12Z SATURDAY IS NEAR THE PANHANDLES
OF TX/OK. EVEN WITH THIS FIRST LOW CREEPING CLOSER TO THE
CWA...PRECIPITATION IS EXPECTED TO REMAIN OFF TO THE SOUTH OF THE
CWA. NOT A LOT OF SWEEPING CHANGES LOOKING AT THE SURFACE PATTERN
EITHER...WHICH STARTS THE PERIOD OFF WITH THE CWA UNDER THE
INFLUENCE OF A HIGH PRESSURE AXIS EXTENDING FROM NM...AND LIGHT
NORTHERLY WINDS. THROUGH FRIDAY NIGHT...HIGH PRESSURE CONTINUES TO
BE A PRIMARY PLAYER ACROSS THE CWA...WITH THE MAIN AXIS DRAPED
ACROSS SRN PORTIONS OF THE CWA...BETWEEN HIGH PRESSURE CENTERS OVER
THE SRN PLAINS AND ANOTHER DRIFTING SE INTO THE GREAT
LAKES/MIDWEST. THIS WILL BRING A RETURN TO MORE SOUTHERLY
FLOW...WITH LIGHTER SPEEDS ACROSS THE SRN CWA AND GUSTIER WINDS TO
ACROSS THE NORTH. ALSO NOT EXPECTING MUCH OF A CHANGE IN AIRMASS
COMPARED TO THURSDAY...AND FORECAST HIGHS ARE WITHIN A FEW DEGREES
IN THE MID 50S.
A LITTLE BIT MORE UNCERTAINTY ARISES AS WE GET INTO THE UPCOMING
WEEKEND...WHICH WILL BE INFLUENCED BY THE MAIN UPPER LEVEL LOW
PRESSURE SYSTEM. THROUGH THE DAYTIME HOURS ON SATURDAY...AGAIN NOT
MUCH PROGRESS IS MADE LOOKING AT THE MODELS...WITH SOLUTIONS VARYING
FROM A MORE ERN PATH LIKE THE GFS/NAM /ENDING UP OVER SCENT KS BY
00Z SUNDAY/...VS A MORE NRN PATH FROM THE EC /UP TOWARD NWRN KS/.
LIFT OUT AHEAD OF THE LOW LOOKS TO BRING SOME SLIGHT CHANCES FOR
PRECIPITATION DURING THE DAY ON SATURDAY...MAINLY ACROSS THE
SRN/SERN THIRD OF THE CWA. SLIGHT PRECIPITATION CHANCES CONTINUE ON
SATURDAY NIGHT AND EVEN INTO SUNDAY...AND KEPT POPS ON THE LOW SIDE
WITH MODELS KEEPING THE MAIN BRUNT OF THE PRECIPITATION OFF TO THE
E/S OF THE CWA. THE DAYTIME HOURS ON SUNDAY HAVE THE MOST AREAL
COVERAGE OF POPS...WITH THE ACTUAL CENTER OF THE UPPER LEVEL LOW
LOOKING TO CROSS THE REGION...THOUGH SLIGHT LOCATION/TIMING
DIFFERENCE CONTINUE BETWEEN MODELS. KEPT THE EVENING/OVERNIGHT
HOURS SUNDAY DRY FOR NOW WITH MORE SUPPORT GETTING THINGS OUT OF
HERE...BUT IT WOULDNT TAKE MUCH OF A SLOW DOWN FOR SOME POPS TO BE
NEEDED IN THE ERN PORTIONS OF THE CWA. TEMP PROFILES AT THIS POINT
KEEP THINGS AS ALL LIQUID...WITH LITTLE/NO INSTABILITY
PRESENT...KEPT ANY THUNDER MENTION OUT AS WELL. TEMPERATURES
THROUGH THE WEEKEND ARE TRICKY...AND WILL BE DEPENDENT ON THE
LOCATION/TIMING OF THE SYSTEM AND ACCOMPANYING CLOUDS/PRECIP.
FORECAST HIGHS CURRENTLY ARE SITTING GENERALLY IN THE MID 50S.
LOOKING TOWARD MONDAY THROUGH WEDNESDAY...THE DRY FORECAST RETURNS
TO THE ENTIRE CWA. IN THE WAKE OF THIS UPPER LEVEL LOW PRESSURE
SYSTEM PASSING THROUGH ON SUNDAY...EXPECTING TO SEE ZONAL/SLIGHTLY
SWRLY FLOW SET UP ACROSS THE REGION...WITH NO NOTABLE SYSTEMS
PUSHING THROUGH. KEPT HIGHS NEAR THE ALLBLEND...WITH MODELS VARYING
WITH THE TIMING/MAGNITUDE OF COOLER AIR OF A FRONTAL BOUNDARY
PUSHING THROUGH EARLY/MIDWEEK. THE GFS IS FASTER/COOLER THAN THE
EC...ALREADY TRYING TO PUSH A FRONT THROUGH ON TUESDAY...WITH THE EC
SHOWING A MORE MILD/WEAKER PASSAGE. FORECAST HIGHS MON THRU WED SIT
MAINLY IN THE MID/UPPER 60S...WITH LOWER 70S POSSIBLE AS WELL ACROSS
THE SOUTH.
PREV DISCUSSION... /ISSUED 1217 PM CST WED MAR 7 2012/
AVIATION...18Z KGRI TAF...MVFR CIGS ARE EXPECTED TO CONTINUE FOR
A FEW MORE HOURS AT KGRI...WITH CEILINGS SLOWLY IMPROVING THROUGH
THE LATE AFTERNOON HOURS...AS THIS MORNINGS COLD FRONT CONTINUES
TO PUSH FURTHER SOUTHEAST. IN ADDITION...STRONG NORTHERLY WINDS
ARE EXPECTED TO RELAX AND BECOME LESS GUSTY AFTER AROUND
08/02Z AS SUN SETS AND PRESSURE GRADIENT SLACKENS...WITH
PREVAILING VFR CONDITIONS EXPECTED THEREAFTER.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...BRYANT
SHORT TERM...ROSSI
LONG TERM...ADO
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1111 PM CST WED MAR 7 2012
.UPDATE...
LATEST RUC DATA INDICATE SHOWERS AND THUNDERSTORMS NOT AS LIKELY
FOR THE REMAINDER OF TONIGHT AS WE WERE THINKING. WITH SOUTHWEST
FLOW ALOFT CONTINUING TONIGHT...I DECIDED NOT TO REMOVE SHOWERS
AND THUNDERSTORMS COMPLETELY FROM THE TONIGHT GRIDS. I JUST
DECREASED POPS TO 20 PERCENT MAX WITH MAINLY SHOWERS AND ISOLATED
THUNDERSTORMS. I ALSO ADJUSTED SKY GRIDS FOR THE REMAINDER OF
TONIGHT TO BRING THEM IN LINE WITH SATELLITE TRENDS AND THE LATEST
RUC DATA. THE LATEST ZONE PRODUCT REFLECTS THESE CHANGES.
OTHERWISE...ALL LOOKS ON TRACK.
HUBER
&&
.PREV DISCUSSION... /ISSUED 528 PM CST WED MAR 7 2012/
AVIATION...
/00Z UPDATE/
VFR CONDITIONS WILL CONTINUE OVER ALL TAF SITES THROUGH THE
REMAINDER OF THE EVENING WITH SOUTHERLY WINDS GUSTING TO AROUND
20KT. AS A COLD FRONT PUSHES SOUTH INTO WEST CENTRAL TEXAS AFTER
MIDNIGHT...CEILINGS WILL DEGRADE TO MVFR AND SHOULD REMAIN MVFR AT
ALL TAF SITES THROUGH THE END OF THE TAF PERIOD. WINDS WILL VEER
TO THE NORTH AFTER FRONTAL PASSAGE...AROUND 15Z AT THE NORTHERN
TERMINALS...AROUND 19Z AT THE SOUTHERN TERMINALS. NORTHERLY WINDS
WILL GUST TO AROUND 25KT IN THE WAKE OF FRONTAL PASSAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 60 67 38 50 40 / 20 30 40 30 30
SAN ANGELO 63 74 40 52 38 / 20 20 40 30 30
JUNCTION 62 74 45 54 41 / 10 20 50 40 40
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
HUBER
AREA FORECAST DISCUSSION
NWS PUEBLO CO
718 AM MST THU MAR 8 2012
.UPDATE...
LAST SEVERAL RUNS OF THE HRRR MODEL CONTINUE TO INDICATE THAT THE
SNOW OVER THE SOUTHERN MOUNTAINS WILL END LATER THIS MORNING AS
DRIER AIR ADVECTS INTO THE REGION. FOR THIS REASON WILL LET THE
WINTER STORM HILITES END LATER THIS MORNING.
&&
.PREV DISCUSSION... /ISSUED 414 AM MST THU MAR 8 2012/
SHORT TERM...
(TODAY AND TONIGHT)
..SNOW FINALLY MATERIALIZING ACROSS THE SANGRES/WETS AND
SURROUNDING AREAS...
CURRENTLY...
DURING THE LAST FEW HOURS...RADAR RETURNS HAVE INCREASED
SIGNIFICANTLY OVER THE SOUTHERN MTNS AND ADJACENT PLAINS.
SNOW...LIKELY HEAVY...WAS INDICATED ON THE EAST SLOPES OF THE WETS
AND IN THE VICINITY OF THE SPANISH PEAKS. COMPOSITE RADAR IS
CLEARLY INDICATING THE CIRCULATION ASSOCIATED WITH THE WELL
DEFINED...ALBEIT COMPACT...UPPER LOW...WHICH WAS LOCATED NEAR THE 4
CORNERS. THE SNOW HAS EXTENDED AS FAR NORTH AND EAST AS
PUEBLO...WHERE A TRACE OF SNOW HAS OCCURRED DURING THE LAST HOUR OR
SO.
TODAY...
MAIN CHANGE TO THE FCST WAS TO EXTEND THE WINTER STORM WARNING UNTIL
6 PM FOR A SMALL PART OF THE REGION. THIS REGION ENCOMPASSES THE
SOUTHERN SANGRE DE CRISTO MOUNTAINS. FOR ALL OTHER AREAS...THE
WINTER STORM WARNING WILL EXPIRE AT NOON.
ALL MODELS CONTINUE TO INDICATE THE HEAVIEST SNOW WILL OCCUR WHERE
IT IS OCCURRING NOW...THAT IS...ALONG THE EAST SLOPES OF THE S MTNS
AND ADJACENT I-25 CORRIDOR. SNOW IS LIKELY OCCURRING ALONG THE E SLOPES
OF THE SAN JUANS BASED ON SAT PIX IMGY AND MEAGER RADAR RETURNS AS
SEEN BY NWS RADARS.
UPPER LOW...WHICH IS LACKING SIGNIFICANTLY IN MOISTURE...IS FCST TO
TRACK E-SE TODAY ACROSS NM. THIS WILL KEEP THE REGION IN DEEP
UPSLOPE FLOW. BEST FORCING WILL BE OVER THE S TIER WHERE I HAVE KEPT
THE POPS THE HIGHEST.
TONIGHT...
ALTHOUGH THE LOW IS FCST TO TRACK BACK NWD AND ACTUALLY RETROGRADE
WWD ACROSS FAR N NM TONIGHT INTO TOMORROW...ALL GUIDANCE IS SHOWING
VERY LITTLE...IF ANY...QPF OVER THE REGION. THE ONLY QPF BEING
PRINTED OUT IS ACROSS THE FAR S TIER...ALONG THE IMMEDIATE CO/NM
BORDER. ALTHOUGH UPSLOPE FLOW IS RATHER STRONG AND DEEP...THIS
SYSTEM IS LACKING (DRAMATICALLY) WRT MOISTURE. SOUNDINGS ACROSS THE
PLAINS SHOW VERY DRY AIR THROUGHOUT THE COLUMN ADVECTING INTO THIS
SYSTEM FROM THE CENTRAL HIGH PLAINS. LIKEWISE...MOST AREAS TONIGHT
WILL SEE MOSTLY CLEAR SKIES...WITH THE EXCEPTION BEING ALONG THE
CO/NM BORDER. /34
LONG TERM...
(FRIDAY THROUGH WEDNESDAY)
FRIDAY AND SATURDAY...THE LOW PRESSURE SYSTEM IS EXPECTED TO SIT IN
THE VICINITY OF THE OK AND TX PANHANDLES ON FRI...BUT HOW IT MOVES
FROM THERE IS REALLY IN QUESTION NOW. MULTIPLE MODELS AND MODEL RUNS
ARE SHOWING DIFFERING SOLUTIONS ON WHERE THE LOW CENTER WILL
TRACK...FROM RETROGRADING BACK TO THE WEST ACROSS NM...TO EJECTING
NORTH...TO SITTING IN PLACE. THE ONE THING MODELS SEEMED TO AGREE
UPON WAS THAT THERE IS NOT A LOT OF MOISTURE ASSOCIATED WITH THIS
SYSTEM...SO WILL FORECAST MEAGER QPF. GIVEN THE UNCERTAINTY OF THE
TRACK...KEPT THE BEST PCPN CHANCES ALONG THE SOUTHERN PORTIONS OF
THE CWA WITH FLOW BANKING UP AGAINST THE SOUTHERN FOOTHILLS AND S
SANGRES. ON SAT...MODELS INDICATE THAT THE LOW WILL FINALLY MAKE
SOME SORT OF MOVE OUT OF THE AREA...AND TAPERED POPS OFF THROUGH
THE DAY. TEMPS BOTH DAYS SHOULD WARM INTO THE 40S AND 50S...WITH
THE COLDEST TEMPS ALONG THE SOUTHERN TIER.
SUNDAY THROUGH WEDNESDAY...THE UPPER LOW EXITS THE REGION...SETTING
UP WEST TO SOUTHWEST FLOW ACROSS THE 4 CORNERS AND ROCKIES INTO THE
NEXT WORK WEEK FOR DRY CONDITIONS AND WARMING TEMPS. 27
AVIATION...
FOR KCOS...MVFR CONDITIONS WILL CONTINUE UNTIL ABOUT 14Z AND THEN
DRIER AIR SHOULD ADVECT IN DECREASING THE CLOUDS. VFR SHOULD LAST
THROUGH THE REST OF THE PERIOD.
FOR KPUB...SAME AS KCOS ALTHOUGH LOWER CIGS/LIGHT SNOW SHOULD LAST
UNTIL ABOUT 16Z.
FOR KALS...OCCNL MVFR CONDITIONS WILL BE POSSIBLE THROUGH ABOUT
15Z...AND THEN MVFR IS EXPECTED THE REST OF THE FCST PERIOD.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 10 AM MST THIS MORNING FOR COZ067-068-
072>075-078>080-087-088.
WINTER WEATHER ADVISORY UNTIL 10 AM MST THIS MORNING FOR COZ066.
&&
$$
34/34
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
311 AM MST THU MAR 8 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 200 AM MST THU MAR 8 2012
THE UPPER LEVEL LOW WAS SAGGING SOUTH ALONG THE AZ-NM BORDER THIS
MORNING THEN WILL EJECT SLOWLY EAST ACROSS SOUTHERN NM THIS
AFTERNOON. ASSOCIATED DYNAMICAL LIFT IS SOUTH OF THE CWA AND WRAP-
AROUND MOISTURE IS LIMITED. THIS WOULD PRODUCE SOME LIGHT
ACCUMULATION IN THE VICINITY OF MONARCH...SLUMGULLION...AND WOLF
CREEK PASSES TODAY. THE HRRR AND NAM12 ALSO PRODUCE LIGHT
ACCUMULATION OVER THE MANCOS RIDGE THROUGH THIS AFTERNOON.
OTHERWISE MOSTLY SUNNY SKIES WILL PREVAIL.
AT THE SURFACE LOW PRESSURE NEAR THE FOUR CORNERS AND COLD HIGH
PRESSURE PUSHING DOWN THE FRONT RANGE IS PRODUCING NE GRADIENT
WINDS. MTN TOP NE WINDS ARE GUSTING 20-30 OVER EXPOSED TERRAIN.
THE GRADIENT RELAXES THROUGH THE AFTERNOON.
TONIGHT THE UPPER LOW SETTLES ONTO THE EASTERN NM PLAINS WHERE IT
WILL LANGUISH INTO THE WEEKEND. THIS KEEPS THE FORECAST AREA IN A
LIGHT EAST FLOW ALOFT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 311 AM MST THU MAR 8 2012
THE MIDRANGE MODELS SEEM TO BE STALLING THE CLOSED LOW OVER NEW
MEXICO FRIDAY AND FRIDAY NIGHT. THE GFS KEEPS THE 500 MB CENTER
OVER NE NM AND THE PANHANDLES OF TX AND OK FRI. THEN LIFTS IT NORTH
INTO EXTREME SE CO SAT...AND TAKES THE LOW CENTER TO WESTERN KS
SUN MORNING. THE ECMWF RETROGRADES THE LOW CENTER BACK TO WESTERN
NM FRI THEN PUSHES IT EAST SAT AND INTO THE TX PANHANDLE ABOUT 18Z
SUN. THE GFS SOLUTION SHOULD RESULT IN NEARLY CLOUDLESS SKIES
NORTH OF THE SAN JUAN MOUNTAINS FRI THROUGH THE WEEKEND. THE ECMWF
WITH ITS LOW CENTER FURTHER WEST MAY KEEP MORE CLOUD COVER OVER
THE SOUTHERN HALF OF THE FORECAST AREA FRI AND SAT. BOTH SCENARIOS
PROVIDE LITTLE CHANCE OF PRECIP OUTSIDE OF ISOLD SHOWERS IN THE SAN
JUANS THRU THE WEEKEND.
SUNDAY IN BOTH MODELS SHOULD BRING CONTINUED WARM ADVECTION AS
THE FLOW ALOFT BECOMES SOUTHWESTERLY. MAX TEMPS SUN THRU WED
SHOULD BE 5-10 DEGREES ABOVE NORMAL ACROSS THE FORECAST AREA.
EXPECT LITTLE CLOUD COVER AND DRY CONDITIONS AS WELL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 200 AM MST THU MAR 8 2012
VFR CONDITIONS WILL DOMINATE INTO FRIDAY. THE EXCEPTION IS SCT SNOW
SHOWERS IN THE SOUTHERN MTNS ALONG AND EAST OF HIGHWAY 550. EXPECT
SCT MVFR CIGS AND VSBY THROUGH THE AFTERNOON THERE WITH MTN TOPS
OCNLY OBSCURED. WIDESPREAD SNOW SHOWERS WILL OCCUR OVER AND EAST
OF MONARCH...SLUMGULLION...AND WOLF CREEK PASSES THAT WILL PRODUCE
MVFR/LOCAL IFR CIGS AND VSBY. ALL OF THESE SOUTHERN SHOWERS WILL
DIMINISH QUICKLY AFTER 6 PM THIS EVENING WITH VFR CONDITIONS
PREVAILING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JOE
LONG TERM....CC
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
815 AM CST THU MAR 8 2012
.DISCUSSION...
307 AM CST
THE IMMEDIATE CONCERNS WITH THE FORECAST ARE WITH THE FALLING
TEMPERATURES...AS WELL AS CONTINUED POST FRONTAL SHOWERS AND EVEN
SOME THUNDER CHANCES THIS MORNING ACROSS THE SOUTHERN HALF OF THE
AREA. THEN ATTENTION TURNS TO RAIN POTENTIAL SUNDAY...FOLLOWED BY
THE TEMPERATURES NEXT WEEK AS A SIGNIFICANT WARM UP...OR RE-WARM UP
WE SHOULD SAY...LOOKS LIKELY.
FOR THE CURRENT SITUATION...A VERY WELL-DEFINED COLD FRONT IS
CLEARING THE FORECAST AREA EARLY THIS MORNING. ROBUSTLY WARM AIR
AHEAD OF THIS FEATURE HELPED CHICAGO BREAK THEIR RECORD WARM LOW
FOR YESTERDAY /54 DEGREES/. THE COMBINATION OF THE FRONTAL PASSAGE
AND RAIN TOOK TEMPERATURES DOWN AS MUCH AS 14 DEGREES IN ONE
HOUR AT SOME LOCATIONS. A GOOD PART OF THE SHOWER ACTIVITY IS
POST-FRONTAL...ASSOCIATED WITH ELEVATED MOISTURE TRANSPORT AND
STRONG CONVERGENCE ALONG THE BOUNDARY. ITS A GOOD THING A LOT OF
THIS IS POST FRONTAL...AS MORE SHOWER ACTIVITY AHEAD OF THE FRONT
COULD HAVE POTENTIALLY STEERED DOWN SOME OF THE 55 KT FLOW AT 1500
FT SEEN ON THE KLOT DOPPLER VELOCITY FOR HOURS AHEAD OF THE FRONT.
THE NORTHWEST WIND SPEEDS BEHIND THE FRONT ARE ACTUALLY QUITE A
BIT LOWER...GUSTING AT TIMES TO NEAR 25 MPH. THIS SHOULD CONTINUE
TO BE THE CASE INTO THIS AFTERNOON.
AN INTERESTING AREA OF ELEVATED CONVECTION IS SEEN IN NORTHERN MO
AS OF 300 AM HAVING ORIGINATED IN KS WITH A SHORT WAVE PER WATER
VAPOR ANALYSIS. THIS AREA CONTINUES TO GROW UPSCALE EAST
NORTHEAST...WELL BEHIND THE FRONT. RUC AND NAM CROSS SECTIONS
THROUGH THIS AREA SHOW STRONG MID-LEVEL FRONTOGENESIS AND A VERY
DEEP LAYER /AROUND 200 MB/ OF NEGATIVE EPV AND SLIGHTLY
DECREASING THETA-E...INDICATING CONVECTIVE INSTABILITY PRESENT.
THE RUC FORECAST FOR THE FORCING AND INSTABILITY...AND HRRR
PROJECTION OF REFLECTIVITY...SEEMS TO HAVE A STRONG HANDLE ON
THIS...WHILE MOST OTHER GUIDANCE DOES NOT. THIS AREA IS FORECAST
BY THE RUC/HRRR TO COME ACROSS THE SOUTHERN HALF OF THE FORECAST
AREA EARLY THIS MORNING. THE CONVECTIVE SIGNAL WEAKENS
SOMEWHAT...BUT STILL THINK ISOLATED TO SCATTERED THUNDER SHOULD BE
SEEN AT LEAST CLOSE IF NOT INTO THE SOUTHERN FORECAST AREA. THERE
COULD BE SOME SMALL HAIL WITH THIS GIVEN THE LOW WET BULB ZERO
VALUES. THIS SHOULD EXIT BY 10 AM TO NOON...WITH LINGERING CLOUDS
BEHIND THE FRONT ACROSS THE SOUTHERN AREA INTO EARLY TO MID
AFTERNOON.
COLD AIR ADVECTION BEHIND THE FRONT WILL UNDERCUT THE MORNING
CLOUDS AND SHOWERS IN THE SOUTH...HELPING TO KEEP TEMPERATURES
NEARLY STEADY OR EVEN CONTINUING TO FALL THROUGH MID-MORNING.
CLEARING BY LATE MORNING INTO AFTERNOON WILL ALLOW FOR SOME
REBOUND...BUT PROBABLY ONLY INTO THE LOWER TO MID 40S. CONFIDENCE
ON THE DEGREE OF RECOVERY IS SOMEWHAT LOW DUE TO WEIGHING THE COLD
AIR ADVECTION/CLOUD IMPACT THIS MORNING.
THE UPPER TROUGH OVER MN EARLY THIS MORNING WILL PASS OVER THE
GREAT LAKES AND BE RE-ENFORCED BY A STRONG JET MAX TO THE
NORTHWEST. THIS WILL HELP TO PUSH A SECONDARY COLD FRONT SOUTH
THROUGH THE AREA LATE THIS EVENING INTO OVERNIGHT. THIS LOOKS TO
REALLY SEND DEW POINTS DOWN AND POTENTIALLY TEMPERATURES FURTHER
TOO. THE COLD POCKET ASSOCIATED WITH THIS SHOULD DEVELOP SOME
STRATOCU TONIGHT ACROSS NORTHERN AND EASTERN AREAS THAT MAY
POTENTIALLY LINGER INTO FRI MORNING.
HIGH PRESSURE WILL THEN PREVAIL FRIDAY INTO EARLY SATURDAY...WITH
RETURN FLOW THEN SETTING UP FOR SATURDAY...WHICH SHOULD BE A
FAIRLY PLEASANT AND SUNNY DAY. THE WELL-ORGANIZED CLOSED UPPER
LOW OVER THE DESERT SOUTHWEST WILL DRIFT GRADUALLY NORTHEAST ON
SATURDAY...THEN BEGIN TO BECOME MORE NEUTRAL TO NEGATIVELY TILED
AS IT LIFTS OVER OUR AREA ON SUNDAY INTO SUNDAY NIGHT. THE
AMOUNT OF MOISTURE RETURN AHEAD OF THIS IS FAIRLY SHORT IN
DURATION...BUT IT CERTAINLY LOOKS TO BE DEEP ENOUGH AND WITHIN
STRONG ENOUGH ISENTROPIC LIFT FOR FAIRLY WIDESPREAD RAIN/SHOWERS
ON SUNDAY. HAVE CONTINUED TO INCH UP POPS. WHILE THE SYSTEM DRY
SLOT EVOLVES RIGHT INTO THE AREA...ELEVATED INSTABILITY IS VERY
MARGINAL DUE TO THE LIMITED DEGREE OF THETA-E RETURN. SO CONTINUE
WITH NO THUNDER MENTION...BUT COULD SEE SOME GUSTIER SHOWERS
POTENTIALLY SUNDAY AFTERNOON AND EVE IF THE GFS/EC PAN OUT AS IS.
SO HAVE MENTIONED MORE OF A SHOWER WORDING DURING THE AFTERNOON
AND EVE BECAUSE OF THIS. TEMPERATURES ON SUNDAY COULD ENCOMPASS A
FAIRLY LARGE RANGE THANKS TO THE IMPACTS OF THE LIKELY RAIN. WITH
CONFIDENCE INCREASING IN RAIN...HAVE CONTINUED NOT TO INCREASE
TEMPERATURES DESPITE SOME GUIDANCE INDICATING WARMER IN SUCCESSIVE
RUNS.
THE GFS REMAINS CONSISTENT WITH HAVING ANOTHER UPPER
WAVE...ACTUALLY ALMOST A PART OF THE FIRST ONE...MOVE NORTHEAST
ACROSS THE OHIO RIVER VALLEY ON MONDAY NIGHT INTO TUESDAY. THE
08.00 EC TRENDED BACK AWAY FROM THIS...BUT HAS BEEN THE LESS
CONSISTENT MODEL. HAVE KEPT POPS ON TUE MAINLY IN SOUTHEAST AREAS
TO ACCOUNT FOR THIS WAVE. WHILE THIS COULD HAVE IMPACTS ON
TEMPERATURES ON TUE...A LOW-LEVEL THERMAL TONGUE IS PROJECTED TO
BE KNOCKING ON OUR DOOR FROM THE WEST AND SHOULD PROVIDE FOR ABOVE
TO WELL ABOVE NORMAL TEMPERATURES. THE STRONGEST SIGNAL FOR VERY
MILD READINGS AND A DRY ATMOSPHERIC COLUMN IS ON WED AT THIS TIME.
AS PREVIOUS SHIFT DID...LEAN THE FORECAST TOWARDS THE BETTER
PERFORMING EC IN THOSE TYPE OF REGIMES. HIGHS IN THE UPPER 60S
INTO THE 70S ARE CURRENTLY WHAT THIS BLENDED APPROACH PRODUCES
AND SEEMS TO MAKE SENSE. WHILE A FRONT IS PRESENTLY FORECAST TO
MOVE THROUGH SOMETIME LATER WED INTO THU OF NEXT WEEK...IT WOULD
SEEM LIKELY WITH THE PATTERN THAT ABOVE NORMAL TEMPERATURES
CONTINUE THROUGH THE LATTER PART OF NEXT WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* OCCASIONAL W/NW GUSTS TO 25 KT.
* LOW END MVFR CIGS UNTIL 16Z THEN STEADY IMPROVEMENT TO VFR.
BEACHLER
//DISCUSSION...UPDATED 12Z...
A STRONG COLD FRONT HAS PUSHED EAST OF THE TERMINALS THIS MORNING.
WITH THE FROPA...WINDS HAVE SHIFTED TO NWLY AND DIMINISHED
SOMEWHAT...THOUGH GUSTS TO 25KT ARE LIKELY THROUGH THE DAY. MUCH
OF THE ASSOCIATED PCPN HAS ENDED...BUT AN UPPER LEVEL IMPULSE
MOVING THROUGH CNTRL IL HAS BROUGHT MORE RAIN AND SOME ISOLD
THUNDER...BUT LATEST RADAR IMAGERY INDICATES A WEAKENING TREND AND
IT IS LIKELY THAT ANY REMAINING PRECIP SHOULD REMAIN SOUTH OF THE
TERMINALS...WITH THE POSSIBLE EXCEPTION OF KGYY WHICH MAY STILL
GET CLIPPED WITH SOME SHRA. OTHERWISE...THE TREND FOR THE DAY
SHOULD BE FOR IMPROVING CIGS AS COOLER...DRIER AIR FILTERS IN
BEHIND THE COLD FRONT. EXPECT THAT CIGS SHOULD IMPROVE TO VFR BY
LATE MORNING. THE REMAINDER OF THE PERIOD SHOULD SEE VFR
CONDITIONS AS HIGH PRESSURE BUILDS ACROSS THE REGION. A WEAK LOW
PRESSURE SYSTEM MOVING THROUGH THE UPPER GREAT LAKES TONIGHT
SHOULD DRAG A SECONDARY COLD FRONT ACROSS THE AREA...BRINGING A
REINFORCING SHOT OF COLD AIR. THIS COLD ADVECTION SHOULD BRING
ANOTHER ROUND OF GUSTINESS DURG THE OVERNIGHT HOURS...THOUGH DO
NOT EXPECT GUSTS TO EXCEED 25KT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN WIND DIR/SPEED FORECAST.
* MEDIUM CONFIDENCE IN TIMING OF CIGS IMPROVEMENT.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT AND SATURDAY...VFR.
SUNDAY AND MONDAY...CHANCE OF RAIN. MVFR POSSIBLE.
TUESDAY...CHANCE OF RAIN AND MVFR EARLY...OTHERWISE VFR.
WEDNESDAY...VFR.
KREIN
&&
.MARINE...
325 AM CST
SOUTHWEST GALES ARE FINALLY COMING TO AN END OVER THE LAKE! THE
COLD FRONT IS ALMOST THROUGH LAKE MICHIGAN...WITH THE
SOUTHEASTERN THIRD OF THE LAKE STILL AWAITING ITS ARRIVAL. WINDS
BEHIND THE COLD FRONT HAVE DIMINISHED AND TURNED WEST TO
NORTHWEST. THE ABRUPT CHANGE IN WIND SPEED AND DIRECTION HAS
HELPED WAVES QUICKLY DIMINISH IN THE NEAR SHORE ZONES...THEREFORE
NOT ISSUING A SMALL CRAFT ADVISORY FOR THIS MORNING. WINDS MAY
GUST TO 25 KT FOR THE NEXT COUPLE OF HOURS...BUT NOT LONG ENOUGH
TO WARRANT A SMALL CRAFT ADVISORY.
A WEAKENING LOW MOVES SOUTH OVER THE EASTERN GREAT LAKES AS THE HIGH
PRESSURE TO OUR WEST MOVES INTO SOUTHERN MINNESOTA. AS THE TWO
SYSTEMS MOVE CLOSER TOGETHER THE PRESSURE GRADIENT TIGHTENS
OVERHEAD. THAT COMBINED WITH STRONG PRESSURE RISES WILL CREATE
NORTHWEST GALES OVER THE NORTHERN TWO THIRDS OF THE LAKE LATE
TONIGHT. GALES WILL BEGIN TO DIMINISH FRIDAY MORNING AS THE HIGH
PRESSURE MOVES INTO THE IMMEDIATE AREA. THE HIGH WILL PASS OVER
THE LAKE LATE FRIDAY AFTERNOON INTO FRIDAY EVENING.
YET ANOTHER ROUND OF GALES IS POSSIBLE ON THE BACKSIDE OF THE HIGH
PRESSURE SATURDAY MORNING. LOW END GALES ARE EXPECTED OVER THE
CENTRAL THIRD OF THE LAKE...WITH GALES UP TO 40 KT LIKELY OVER THE
NORTHERN THIRD OF THE LAKE. NOT ANTICIPATING GALES OVER THE
SOUTHERN THIRD OF THE LAKE. GALES BEGIN TO DIMINISH SATURDAY
AFTERNOON AS THE HIGH PRESSURE PULLS AWAY TO THE EAST...HOWEVER
GALES OVER THE NORTHERN END OF THE LAKE LOOK LIKE THEY WILL PERSIST
INTO THE EVENING HOURS.
MODELS HAVE SIGNIFICANT DISCREPANCIES IN TIMING AND THE OVERALL
PATTERN FOR THE REMAINDER OF THE FORECAST...SO WHILE NO GALES ARE
FORECAST FOR NEXT WEEK...FORECAST CONFIDENCE IS LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...3 AM FRIDAY TO 9
PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
603 AM CST THU MAR 8 2012
.DISCUSSION...
307 AM CST
THE IMMEDIATE CONCERNS WITH THE FORECAST ARE WITH THE FALLING
TEMPERATURES...AS WELL AS CONTINUED POST FRONTAL SHOWERS AND EVEN
SOME THUNDER CHANCES THIS MORNING ACROSS THE SOUTHERN HALF OF THE
AREA. THEN ATTENTION TURNS TO RAIN POTENTIAL SUNDAY...FOLLOWED BY
THE TEMPERATURES NEXT WEEK AS A SIGNIFICANT WARM UP...OR RE-WARM UP
WE SHOULD SAY...LOOKS LIKELY.
FOR THE CURRENT SITUATION...A VERY WELL-DEFINED COLD FRONT IS
CLEARING THE FORECAST AREA EARLY THIS MORNING. ROBUSTLY WARM AIR
AHEAD OF THIS FEATURE HELPED CHICAGO BREAK THEIR RECORD WARM LOW
FOR YESTERDAY /54 DEGREES/. THE COMBINATION OF THE FRONTAL PASSAGE
AND RAIN TOOK TEMPERATURES DOWN AS MUCH AS 14 DEGREES IN ONE
HOUR AT SOME LOCATIONS. A GOOD PART OF THE SHOWER ACTIVITY IS
POST-FRONTAL...ASSOCIATED WITH ELEVATED MOISTURE TRANSPORT AND
STRONG CONVERGENCE ALONG THE BOUNDARY. ITS A GOOD THING A LOT OF
THIS IS POST FRONTAL...AS MORE SHOWER ACTIVITY AHEAD OF THE FRONT
COULD HAVE POTENTIALLY STEERED DOWN SOME OF THE 55 KT FLOW AT 1500
FT SEEN ON THE KLOT DOPPLER VELOCITY FOR HOURS AHEAD OF THE FRONT.
THE NORTHWEST WIND SPEEDS BEHIND THE FRONT ARE ACTUALLY QUITE A
BIT LOWER...GUSTING AT TIMES TO NEAR 25 MPH. THIS SHOULD CONTINUE
TO BE THE CASE INTO THIS AFTERNOON.
AN INTERESTING AREA OF ELEVATED CONVECTION IS SEEN IN NORTHERN MO
AS OF 300 AM HAVING ORIGINATED IN KS WITH A SHORT WAVE PER WATER
VAPOR ANALYSIS. THIS AREA CONTINUES TO GROW UPSCALE EAST
NORTHEAST...WELL BEHIND THE FRONT. RUC AND NAM CROSS SECTIONS
THROUGH THIS AREA SHOW STRONG MID-LEVEL FRONTOGENESIS AND A VERY
DEEP LAYER /AROUND 200 MB/ OF NEGATIVE EPV AND SLIGHTLY
DECREASING THETA-E...INDICATING CONVECTIVE INSTABILITY PRESENT.
THE RUC FORECAST FOR THE FORCING AND INSTABILITY...AND HRRR
PROJECTION OF REFLECTIVITY...SEEMS TO HAVE A STRONG HANDLE ON
THIS...WHILE MOST OTHER GUIDANCE DOES NOT. THIS AREA IS FORECAST
BY THE RUC/HRRR TO COME ACROSS THE SOUTHERN HALF OF THE FORECAST
AREA EARLY THIS MORNING. THE CONVECTIVE SIGNAL WEAKENS
SOMEWHAT...BUT STILL THINK ISOLATED TO SCATTERED THUNDER SHOULD BE
SEEN AT LEAST CLOSE IF NOT INTO THE SOUTHERN FORECAST AREA. THERE
COULD BE SOME SMALL HAIL WITH THIS GIVEN THE LOW WET BULB ZERO
VALUES. THIS SHOULD EXIT BY 10 AM TO NOON...WITH LINGERING CLOUDS
BEHIND THE FRONT ACROSS THE SOUTHERN AREA INTO EARLY TO MID
AFTERNOON.
COLD AIR ADVECTION BEHIND THE FRONT WILL UNDERCUT THE MORNING
CLOUDS AND SHOWERS IN THE SOUTH...HELPING TO KEEP TEMPERATURES
NEARLY STEADY OR EVEN CONTINUING TO FALL THROUGH MID-MORNING.
CLEARING BY LATE MORNING INTO AFTERNOON WILL ALLOW FOR SOME
REBOUND...BUT PROBABLY ONLY INTO THE LOWER TO MID 40S. CONFIDENCE
ON THE DEGREE OF RECOVERY IS SOMEWHAT LOW DUE TO WEIGHING THE COLD
AIR ADVECTION/CLOUD IMPACT THIS MORNING.
THE UPPER TROUGH OVER MN EARLY THIS MORNING WILL PASS OVER THE
GREAT LAKES AND BE RE-ENFORCED BY A STRONG JET MAX TO THE
NORTHWEST. THIS WILL HELP TO PUSH A SECONDARY COLD FRONT SOUTH
THROUGH THE AREA LATE THIS EVENING INTO OVERNIGHT. THIS LOOKS TO
REALLY SEND DEW POINTS DOWN AND POTENTIALLY TEMPERATURES FURTHER
TOO. THE COLD POCKET ASSOCIATED WITH THIS SHOULD DEVELOP SOME
STRATOCU TONIGHT ACROSS NORTHERN AND EASTERN AREAS THAT MAY
POTENTIALLY LINGER INTO FRI MORNING.
HIGH PRESSURE WILL THEN PREVAIL FRIDAY INTO EARLY SATURDAY...WITH
RETURN FLOW THEN SETTING UP FOR SATURDAY...WHICH SHOULD BE A
FAIRLY PLEASANT AND SUNNY DAY. THE WELL-ORGANIZED CLOSED UPPER
LOW OVER THE DESERT SOUTHWEST WILL DRIFT GRADUALLY NORTHEAST ON
SATURDAY...THEN BEGIN TO BECOME MORE NEUTRAL TO NEGATIVELY TILED
AS IT LIFTS OVER OUR AREA ON SUNDAY INTO SUNDAY NIGHT. THE
AMOUNT OF MOISTURE RETURN AHEAD OF THIS IS FAIRLY SHORT IN
DURATION...BUT IT CERTAINLY LOOKS TO BE DEEP ENOUGH AND WITHIN
STRONG ENOUGH ISENTROPIC LIFT FOR FAIRLY WIDESPREAD RAIN/SHOWERS
ON SUNDAY. HAVE CONTINUED TO INCH UP POPS. WHILE THE SYSTEM DRY
SLOT EVOLVES RIGHT INTO THE AREA...ELEVATED INSTABILITY IS VERY
MARGINAL DUE TO THE LIMITED DEGREE OF THETA-E RETURN. SO CONTINUE
WITH NO THUNDER MENTION...BUT COULD SEE SOME GUSTIER SHOWERS
POTENTIALLY SUNDAY AFTERNOON AND EVE IF THE GFS/EC PAN OUT AS IS.
SO HAVE MENTIONED MORE OF A SHOWER WORDING DURING THE AFTERNOON
AND EVE BECAUSE OF THIS. TEMPERATURES ON SUNDAY COULD ENCOMPASS A
FAIRLY LARGE RANGE THANKS TO THE IMPACTS OF THE LIKELY RAIN. WITH
CONFIDENCE INCREASING IN RAIN...HAVE CONTINUED NOT TO INCREASE
TEMPERATURES DESPITE SOME GUIDANCE INDICATING WARMER IN SUCCESSIVE
RUNS.
THE GFS REMAINS CONSISTENT WITH HAVING ANOTHER UPPER
WAVE...ACTUALLY ALMOST A PART OF THE FIRST ONE...MOVE NORTHEAST
ACROSS THE OHIO RIVER VALLEY ON MONDAY NIGHT INTO TUESDAY. THE
08.00 EC TRENDED BACK AWAY FROM THIS...BUT HAS BEEN THE LESS
CONSISTENT MODEL. HAVE KEPT POPS ON TUE MAINLY IN SOUTHEAST AREAS
TO ACCOUNT FOR THIS WAVE. WHILE THIS COULD HAVE IMPACTS ON
TEMPERATURES ON TUE...A LOW-LEVEL THERMAL TONGUE IS PROJECTED TO
BE KNOCKING ON OUR DOOR FROM THE WEST AND SHOULD PROVIDE FOR ABOVE
TO WELL ABOVE NORMAL TEMPERATURES. THE STRONGEST SIGNAL FOR VERY
MILD READINGS AND A DRY ATMOSPHERIC COLUMN IS ON WED AT THIS TIME.
AS PREVIOUS SHIFT DID...LEAN THE FORECAST TOWARDS THE BETTER
PERFORMING EC IN THOSE TYPE OF REGIMES. HIGHS IN THE UPPER 60S
INTO THE 70S ARE CURRENTLY WHAT THIS BLENDED APPROACH PRODUCES
AND SEEMS TO MAKE SENSE. WHILE A FRONT IS PRESENTLY FORECAST TO
MOVE THROUGH SOMETIME LATER WED INTO THU OF NEXT WEEK...IT WOULD
SEEM LIKELY WITH THE PATTERN THAT ABOVE NORMAL TEMPERATURES
CONTINUE THROUGH THE LATTER PART OF NEXT WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* GUSTY WEST TO NORTHWEST WINDS WITH OCNL GUSTS TO 25KT.
* LOWER END MVFR CIGS THROUGH LATE MORNING.
KREIN
//DISCUSSION...UPDATED 12Z...
A STRONG COLD FRONT HAS PUSHED EAST OF THE TERMINALS THIS MORNING.
WITH THE FROPA...WINDS HAVE SHIFTED TO NWLY AND DIMINISHED
SOMEWHAT...THOUGH GUSTS TO 25KT ARE LIKELY THROUGH THE DAY. MUCH
OF THE ASSOCIATED PCPN HAS ENDED...BUT AN UPPER LEVEL IMPULSE
MOVING THROUGH CNTRL IL HAS BROUGHT MORE RAIN AND SOME ISOLD
THUNDER...BUT LATEST RADAR IMAGERY INDICATES A WEAKENING TREND AND
IT IS LIKELY THAT ANY REMAINING PRECIP SHOULD REMAIN SOUTH OF THE
TERMINALS...WITH THE POSSIBLE EXCEPTION OF KGYY WHICH MAY STILL
GET CLIPPED WITH SOME SHRA. OTHERWISE...THE TREND FOR THE DAY
SHOULD BE FOR IMPROVING CIGS AS COOLER...DRIER AIR FILTERS IN
BEHIND THE COLD FRONT. EXPECT THAT CIGS SHOULD IMPROVE TO VFR BY
LATE MORNING. THE REMAINDER OF THE PERIOD SHOULD SEE VFR
CONDITIONS AS HIGH PRESSURE BUILDS ACROSS THE REGION. A WEAK LOW
PRESSURE SYSTEM MOVING THROUGH THE UPPER GREAT LAKES TONIGHT
SHOULD DRAG A SECONDARY COLD FRONT ACROSS THE AREA...BRINGING A
REINFORCING SHOT OF COLD AIR. THIS COLD ADVECTION SHOULD BRING
ANOTHER ROUND OF GUSTINESS DURG THE OVERNIGHT HOURS...THOUGH DO
NOT EXPECT GUSTS TO EXCEED 25KT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MODERATE CONFIDENCE IN CEILING TRENDS.
* MODERATE TO HIGH CONFIDENCE IN WIND TRENDS.
* MODERATE TO HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT AND SATURDAY...VFR.
SUNDAY AND MONDAY...CHANCE OF RAIN. MVFR POSSIBLE.
TUESDAY...CHANCE OF RAIN AND MVFR EARLY...OTHERWISE VFR.
WEDNESDAY...VFR.
KREIN
&&
.MARINE...
325 AM CST
SOUTHWEST GALES ARE FINALLY COMING TO AN END OVER THE LAKE! THE
COLD FRONT IS ALMOST THROUGH LAKE MICHIGAN...WITH THE
SOUTHEASTERN THIRD OF THE LAKE STILL AWAITING ITS ARRIVAL. WINDS
BEHIND THE COLD FRONT HAVE DIMINISHED AND TURNED WEST TO
NORTHWEST. THE ABRUPT CHANGE IN WIND SPEED AND DIRECTION HAS
HELPED WAVES QUICKLY DIMINISH IN THE NEAR SHORE ZONES...THEREFORE
NOT ISSUING A SMALL CRAFT ADVISORY FOR THIS MORNING. WINDS MAY
GUST TO 25 KT FOR THE NEXT COUPLE OF HOURS...BUT NOT LONG ENOUGH
TO WARRANT A SMALL CRAFT ADVISORY.
A WEAKENING LOW MOVES SOUTH OVER THE EASTERN GREAT LAKES AS THE HIGH
PRESSURE TO OUR WEST MOVES INTO SOUTHERN MINNESOTA. AS THE TWO
SYSTEMS MOVE CLOSER TOGETHER THE PRESSURE GRADIENT TIGHTENS
OVERHEAD. THAT COMBINED WITH STRONG PRESSURE RISES WILL CREATE
NORTHWEST GALES OVER THE NORTHERN TWO THIRDS OF THE LAKE LATE
TONIGHT. GALES WILL BEGIN TO DIMINISH FRIDAY MORNING AS THE HIGH
PRESSURE MOVES INTO THE IMMEDIATE AREA. THE HIGH WILL PASS OVER
THE LAKE LATE FRIDAY AFTERNOON INTO FRIDAY EVENING.
YET ANOTHER ROUND OF GALES IS POSSIBLE ON THE BACKSIDE OF THE HIGH
PRESSURE SATURDAY MORNING. LOW END GALES ARE EXPECTED OVER THE
CENTRAL THIRD OF THE LAKE...WITH GALES UP TO 40 KT LIKELY OVER THE
NORTHERN THIRD OF THE LAKE. NOT ANTICIPATING GALES OVER THE
SOUTHERN THIRD OF THE LAKE. GALES BEGIN TO DIMINISH SATURDAY
AFTERNOON AS THE HIGH PRESSURE PULLS AWAY TO THE EAST...HOWEVER
GALES OVER THE NORTHERN END OF THE LAKE LOOK LIKE THEY WILL PERSIST
INTO THE EVENING HOURS.
MODELS HAVE SIGNIFICANT DISCREPANCIES IN TIMING AND THE OVERALL
PATTERN FOR THE REMAINDER OF THE FORECAST...SO WHILE NO GALES ARE
FORECAST FOR NEXT WEEK...FORECAST CONFIDENCE IS LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...3 AM FRIDAY TO 9
PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
516 AM CST THU MAR 8 2012
.DISCUSSION...
ISSUED 314 AM CST THU MAR 8 2012
COLD FRONT PUSHING THROUGH THE FORECAST AREA THIS MORNING WITH SOME
SHOWERS OUT AHEAD AND ALONG. A SECOND ROUND OF SHOWERS AND
OCCASIONAL THUNDER PUSHING UP JUST BEHIND THE SFC BOUNDARY AS A WAVE
MOVES NE INTO THE REGION. MORNING PRECIP AND HOW LONG IT WILL IMPACT
THE REGION IS THE FIRST ISSUE...ALONG WITH THE HOURLY TEMPS THIS
MORNING AS COLDER AIR MOVES INTO THE AREA. BEYOND THAT...THE
FORECAST HAS FEW CHANGES AS THE MODELS STILL WORK OUT HOW THE MAIN
UPPER LOW OVER THE SWRN CONUS IS GOING TO MOVE OUT AND ACROSS THE
ERN HALF OF THE COUNTRY. STILL MORE IN FAVOR OF THE ECMWF...AND HAVE
TRIED TO MITIGATE THE GFS IMPACTS IN THE EXTENDED AS MUCH AS
COLLABORATION AND CONSENSUS WOULD ALLOW. THAT BEING SAID...THE GFS
SOLUTION OF SPLITTING THE WAVE INTO SEVERAL SMALLER WAVES IS SLOWLY
TURNING INTO A MORE ECMWF/NAM SOLUTION. BIGGEST IMPACT FOR THIS
PARTICULAR DISCREPANCY WILL BE ON MON NIGHT/TUESDAY WHERE THE
CONFIDENCE IN THE GOING FORECAST DECREASES.
SHORT TERM...TODAY AND TOMORROW...
HIGH TEMPERATURES LIKELY TO BE MET EARLY AS THE REMAINDER OF THE DAY
WILL BE COOLER WITH THE FRONT PASSING THROUGH THIS MORNING. PRECIP
WILL CONTINUE WITH A CHANCE FOR SOME THUNDER THIS MORNING WITH SOME
STEEPER MID LEVEL LAPSE RATES ASSOCIATED WITH THE WAVE MOVING
THROUGH THE FLOW JUST BEHIND THE SFC BOUNDARY. POPS DECREASING NW TO
SE AFTER 18Z. TEMPS A BIT COOLER TONIGHT. CONCERN THAT GUIDANCE AND
GOING FORECAST ARE NOT QUITE COOL ENOUGH SHOULD THE SKIES CLEAR A
BIT MORE QUICKLY THAN THE MODEL RH PROFILES ARE HINTING. RATHER DRY
AIR AVAILABLE BEHIND THIS WAVE. TOMORROW...TEMPS COOLER THAN LAST
COUPLE OF DAYS...BUT STILL A BIT WARMER THAN SEASONABLE...UPPER
40S/NEAR 50 WITH PLENTY OF SUNSHINE.
LONG TERM...SATURDAY THROUGH WEDNESDAY...
WINDS COME AROUND TO MORE SOUTHERLY SATURDAY MORNING...AND ASSISTS
IN A WARM UP WITH PLENTY OF SUNSHINE EARLY. HOWEVER...SOME OF THIS
WARM UP WILL BE SHORT LIVED AS A DEVELOPING SYSTEM MOVES OUT OF THE
SRN PLAINS INTO THE MIDWEST. MODELS HAVE HAD QUITE THE HISTORY WITH
THIS SYSTEM...AND MANY MANY DIFFERENT SOLUTIONS. FOR NOW...THE EC IS
PUSHING THE SYSTEM THROUGH...RATHER DIFFUSE AS AN OPEN WAVE...AND
WEAKENING AND LESSENING THE QPF TRENDS IN THE LAST COUPLE OF RUNS.
THE GFS IS ALSO EASING A BIT...BUT DELIVERING THE PRECIP IN A ONE
TWO PUNCH FOR SAT NIGHT/SUN AND MON NIGHT/TUES. FOR NOW...BEST
CHANCES FOR POPS ARE IN THE FORECAST WITH SUNDAY AND SUNDAY NIGHT.
FROM TUES NIGHT THROUGH WED...KEEPING THE FORECAST DRY AT THIS POINT
AS THE MODELS ARE STRUGGLING WITH A BIT OF FEEDBACK IN WEAK SWRLY
FLOW.
HJS
&&
.AVIATION...
ISSUED 516 AM CST THU MAR 8 2012
COLD FRONT HAS PASSED THROUGH THE TAF SITES THIS MORNING...WITH A
BRIEF LULL IN THE PRECIPITATION. SHOWERS WILL RAMP UP AGAIN EARLY AS
A SHORTWAVE MOVES FROM NORTHERN MO ACROSS CENTRAL IL. SINCE
LIGHTNING HAS DECREASED IN THE PAST COUPLE OF HOURS...WILL JUST HAVE
SOME VCTS IN THE MORNING. PRECIPITATION MAY MIX WITH LIGHT SNOW OR
LIGHT SLEET AT PIA AS TEMPERATURES FALL THROUGH THE 30S ON THE BACK
EDGE OF THE RAIN SHIELD. THE LATEST RUN OF THE HRRR MODEL HAS A
DECENT HANDLE ON THE CURRENT WEATHER...SO WILL FOLLOW THIS AND
EXPECT PRECIPITATION TO END AT PIA 15Z-16Z...AND AT CMI AROUND 18Z.
CEILINGS/FLIGHT RULES VARY WIDELY OVER THE AREA THIS MORNING...BUT
EXPECT GENERAL MVFR CONDITIONS WITH POSSIBLY IFR IN HEAVIER SHOWERS.
OVERALL EXPECT IMPROVEMENT TO VFR A COUPLE OF HOURS AFTER
PRECIPITATION ENDS...THEN MAINLY CLEAR SKIES BY 00Z FRI. NORTHWEST
WINDS WILL STILL BE ON THE STRONG SIDE TODAY WITH 18-22 KT SUSTAINED
WITH GUSTS ABOVE 30 KT AT TIMES. WINDS WILL THEN DIMINISH AND BACK
TO WESTERLY AFTER 00Z FRI.
04
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
640 AM EST THU MAR 8 2012
.AVIATION...
FRONT WORKING THROUGH AREA WITH WINDS BECOMING NORTHWEST IN ITS
WAKE. AREA OF PRECIPITATION ALONG FRONT ALSO WORKING EAST. WILL HAVE
TO WATCH AREA OF POST FRONTAL PCPN THAT HAS BEEN WORKING NORTHEAST
OVERNIGHT AND WILL LIKELY MOVE INTO KFWA BY 14 TO 15Z WITH MVFR
RESTRICTIONS. SKIES CLEAR LATER TODAY WITH DRIER AIR. SECONDARY WAVE
DROPS INTO AREA LATER TONIGHT WITH INCREASE IN CLOUDS BUT SHOULD BE
VFR.
&&
.SHORT TERM...
STRONG COLD FRONT WAS JUST COMING INTO FAR NW CWA AT 09Z AND WILL
QUICKLY MOVE ACROSS THE AREA TODAY. RADAR SHOWING AREA OF LIGHT TO
MODERATE SHOWERS ALONG AND BEHIND FRONT WITH SCATTERED SHOWERS OUT
AHEAD OF IT. SURFACE OBS SHOWING A GOOD 10 TO 15 DEGREE TEMP DROP
BEHIND FRONT WITH COLD AIR ADVECTION EXPECTED TO CONTINUE THROUGH
THE DAY WITH LITTLE RECOVERY IN TEMPS EXPECTED. HAVE TRIED TO TIME
FRONT THROUGH THE AREA WITH TEMPERATURE DROP AND PCPN TRENDS. VERY
DIFFICULT TO SAY THE LEAST AND ADJUSTMENTS WILL BE NECESSARY THROUGH
THE MORNING. REGIONAL RADAR MOSAIC AND SATELLITE ALSO SHOWING AN
AREA OF CONVECTION THAT HAS DEVELOPED OVERNIGHT IN OK AND KS AND IS
MOVING NORTHEAST. HRRR SEEMS TO BE ONLY MODEL TO HAVE A DECENT
HANDLE ON THIS WITH 04Z AND 05Z MODEL RUNS HAVING THIS WAVE COMING
INTO NW INDIANA AROUND 14Z. DISCUSSION WITH HPC SUGGEST 06Z RUN
TRENDING FARTHER EAST BUT GIVEN LOOKS OF RESPONSIBLE SHORT WAVE ON
WATER VAPOR AND RECENT RADAR MOSAIC TRENDS HAVE CONCERNS THAT THIS
MAY MOVE BACK INTO PART OF CENTRAL OR WEST CENTRAL CWA BY MID
MORNING. FOR THIS REASON HAVE SLOWED THE TREND OF CLEARING POPS
ACROSS THE AREA BY ABOUT 3 TO 5 HOURS TO ACCOUNT FOR THE POSSIBILITY
OF THIS RAIN MOVING BACK IN. BY AFTERNOON THIS WAVE LOOKS TO CLEAR
THE AREA AND RAPID DRYING BEGINS AND SHOULD SEE CLEARING SKIES.
ANOTHER FAST MOVING SHORT WAVE PASSES TO THE NORTH TONIGHT BUT
DRIVES SECONDARY COLD FRONT THROUGH. MAY SEE SOME INCREASE IN CLOUDS
NORTH WITH THIS WAVE AND LAKE PLUME AS DELTA T VALUES CLIMB INTO THE
TEENS. REMAINDER OF SHORT TERM FORECAST DRY WITH HIGH PRESSURE
MOVING IN FRIDAY NIGHT. THIS SHOULD ALLOW WINDS TO DECOUPLE AND
EXPECT GOOD RADIATIONAL COOLING BEFORE RETURN FLOW TRIES TO DEVELOP
LATE. HAVE LOWERED TEMPS FRIDAY NIGHT.
&&
.LONG TERM...
SATURDAY THROUGH WEDNESDAY...A LONG WAVE TROF WILL BECOME ENTRENCHED
ALONG THE WESTERN NORTH AMERICAN COAST WITH LARGE SCALE
AMPLIFICATION DOWNSTREAM OVER THE CENTRAL AND EASTERN CONUS. MUCH
WARMER AIR WILL RETURN TO THE AREA AND PERSIST THROUGH NEXT WEEK.
SHORT WAVE ENERGY WILL EJECT NORTHEAST AND PROVIDE A CHANCE FOR
SHOWERS THROUGH MOST OF THE PERIOD AS GULF MOISTURE SPREADS NORTH
ACROSS THE OHIO RIVER. THE GFS ENSEMBLE MEMBERS HAVE FINALLY COME
INTO REASONABLE AGREEMENT WITH ONE ANOTHER WITH MUCH SMALLER
STANDARD DEVIATIONS REFLECTED IN THE MEX MOS. THERE IS POTENTIAL
FOR HIGHS TO TOP 70 DEGREES DURING THE LATTER HALF OF THIS PERIOD.
HOWEVER...GIVEN THE POTENTIAL FOR CLOUDS AND RAINFALL...KEPT HIGHS
IN THE MID TO UPPER 60S TUESDAY/WEDNESDAY. ALSO...THERE IS AN
OUTSIDE CHANCE ONE OF THE SHORTWAVES MAY BE ABLE TO TAP A LITTLE
COOLER AIR AFTER THE SHORT WAVE PASSES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM EST FRIDAY FOR LMZ043-046.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS GOODLAND KS
532 AM MST THU MAR 8 2012
.UPDATE...
ISSUED AT 522 AM MST THU MAR 8 2012
STARTING TO SEE 12Z RAOBS COME IN AND AS EXPECTED AIR MASS BUILDING
IN FROM THE NORTH LOOKS MUCH DRIER THAN PREVIOUS DAY. ESTIMATED
MIXED LAYER DEWPOINTS OFF OF KLBF SOUNDING WOULD SUPPORT SINGLE
DIGIT DEWPOINTS WITH ANY DEEP MIXING. GOES SOUNDINGS ALSO
SUPPORTING VERY DRY LAYER ALOFT...AND THINK WITH PLENTIFUL
SUNSHINE MUCH OF THE AREA WILL TAP INTO THIS DRIER AIR THIS
AFTERNOON. DROPPING TDS INTO SINGLE DIGITS ALONG THE LINES OF
LATEST HRRR STILL KEEP AFTERNOON HUMIDITY VALUES JUST ABOVE
CRITICAL VALUES. WITH STRONGEST WINDS LIKELY BEFORE 20Z...THE
MARGINAL NATURE OF PARAMETERS AND UNCERTAINTY IF WINDS/RH WILL
LINE UP FOR SEVERAL HOURS KEEPS CONFIDENCE TOO LOW TO ISSUE A RFW
AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 155 AM MST THU MAR 8 2012
TODAY...AREA OF THUNDERSTORMS THAT DEVELOPED ALONG NOSE OF STRONG
ISENTROPIC ASCENT SHOULD CONTINUE TO DIMINISH/SHIFT SOUTH OF THE
AREA THROUGH THE MORNING HOURS AS COLD AND DRY AIR ADVECTION
OVERSPREAD THE AREA BEHIND DEPARTING TROUGH MOVING ACROSS EASTERN
NEBRASKA. WITH MUCH DRIER AIR MOVING INTO THE AREA AND FAIRLY DEEP
DOWNWARD MOTION...DO NOT SEE MUCH IN THE WAY OF A PRECIPITATION THREAT
ONCE OVERNIGHT CONVECTION BEGINS TO SHIFT SOUTH. SKIES WILL
GRADUALLY CLEAR...ALTHOUGH PLACEMENT OF CUT OF LOW AND PERSISTENT
DEFORMATION ZONE MAY PROMOTE A PERSISTENT AREA OF MID/HIGH CLOUDS
ACROSS SOUTHERN CWA...BUT AM NOT EXPECTING MUCH OF AN IMPACT ON
SENSIBLE WX AT THIS TIME. TEMPERATURES SHOULD REBOUND INTO THE LOWER
50S ACROSS MUCH OF THE AREA DESPITE THE CAA WITH GUSTY NORTHERLY
WINDS EXPECTED BTWN 15 AND 20Z BEFORE THINGS BEGIN TO DIMINISH. WITH
LOW TEENS/SINGLE DIGIT DEWPOINTS MOVING INTO THE AREA...EXPECT
HUMIDITIES TO FALL TO AROUND 20 PERCENT RANGE AND WITH THE GUSTY
WINDS MAY APPROACH CRITICAL FIRE WX CONDITIONS FOR AN HOUR OR SO.
CURRENTLY HUMIDITIES LOOK TO BE ABOVE CRITERIA AND WINDS ARE
EXPECTED TO DIMINISH WHILE HUMIDITIES ARE AT THEIR LOWEST VALUES.
HAVE SEEN A FEW POST FRONTAL FIRE WEATHER EVENTS THOUGH WITH DEEP
COLD AND DRY AIR ADVECTION AND MAY NEED TO REEVALUATE ONCE 12Z RAOBS
ARE AVAILABLE.
TONIGHT-FRIDAY...GENERAL CONSENSUS IS UPPER LOW WILL MOVE INTO THE TEXAS
PANHANDLE...WELL REMOVED FROM THE FORECAST AREA...WITH GEM AND SREF
MEAN CONTINUING TO INDICATE SOME RETROGRADE MOTION. BOTH OF THESE
SOLUTIONS AND GENERAL MODEL CONSENSUS KEEPS CWA WELL TO THE NORTH OF
ANY APPRECIABLE PRECIPITATION THREAT AS STABLE MID LEVELS...AND
PERSISTENT DRY NORTHERLY FLOW OVERNIGHT THURSDAY WILL BE ENOUGH TO
PREVENT PRECIP DEVELOPMENT...EVEN IF SOME LARGE SCALE FORCING FOR
ASCENT MAY BE PRESENT. MID LEVEL FLOW EXPECTED TO BECOME A BIT MORE
SOUTHERLY DURING THE DAY ALLOWING FOR SOME INCREASING CLOUDS...BUT
WITH BULK OF LARGE SCALE FORCING FOR ASCENT TO THE SOUTH OF THE AREA
AND OVERALL LOW CONFIDENCE IN LARGE SCALE FEATURES...THINK DRY
CONDITIONS WILL PREVAIL.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 155 AM MST THU MAR 8 2012
FRIDAY NIGHT-SATURDAY NIGHT...WHILE NEAR TERM MODELS HAVE COME INTO A
LITTLE BETTER AGREEMENT WITH HOW H5 TROUGH WILL GRADUALLY LIFT TO
THE NORTH ACROSS THE AREA THROUGH THE PERIOD...THERE REMAINS
CONSIDERABLE SPREAD WITH RESPECT TO THE TIMING DIFFERENCES GREATER
THAN 12 HOURS NOTED IN THE GEFS SPAGHETTI PLOTS FOR THE PERIOD.
GIVEN THE FAIRLY COLD TEMPS ALOFT LEADING TO SOME DESTABILIZATION
AND PV ADVECTION...THINK THERE IS AT LEAST A SMALL THREAT FOR
PRECIPITATION AS IT PASSES. HOWEVER WITH AFOREMENTIONED UNCERTAINTY
WITH RESPECT TO TIMING...CAN NOT REALLY JUSTIFY ANY MORE THAN SLIGHT
PROBABILITIES AT THIS POINT FOR SATURDAY AND SATURDAY
NIGHT...ALTHOUGH SLIGHTLY PREFER A SLOWER SOLUTION WHICH WOULD
IMPACT AREA MORE ON SATURDAY NIGHT. -JRM
SUNDAY THROUGH WEDNESDAY...MODELS ARE CONTINUING TO COME INTO
BETTER AGREEMENT WITH TRACK OF THE UPPER LEVEL CLOSED FOR THIS
PERIOD. CURRENT GUIDANCE HAS THE CLOSED LOW MOVING OVER THE AREA
SUNDAY. PLACED IN SLIGHT CHANCES FOR THE EASTERN PART OF THE AREA
WHERE ISENTROPIC LIFT AND 5-7H FRONTOGENESIS DEVELOP AHEAD OF THE
CLOSED LOW AS IT MOVES THROUGH. AN UPPER LEVEL TROUGH JUST BEHIND
THE CLOSED LOW WILL ALSO LIFT NORTHEAST SUNDAY NIGHT INTO
MONDAY...BUT WILL REMAIN WELL SOUTH OF THE AREA. MONDAY A SHORT
WAVE RIDGE MOVES IN BEHIND THE CLOSED LOW. TUESDAY AND WEDNESDAY
THE UPPER LEVEL FLOW TURNS TO THE SOUTHWEST...BRINGING DRY AIR
OVER THE AREA WHILE A SHORTWAVE TROUGH MOVES ACROSS THE NORTHWEST
CONUS.
TEMPERATURES FOR THE PERIOD WILL BE ABOVE NORMAL...WITH HIGHS AROUND
70 AND LOWS AROUND 40 BY THE START OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 410 AM MST THU MAR 8 2012
VFR CONDITIONS EXPECTED FOR ENTIRE PERIOD AS DRY SFC HIGH PRESSURE
SETTLES OVER THE AREA. NORTHERLY WINDS WILL INCREASE TO 15 TO 20
KTS WITH HIGHER GUSTS BTWN 15 AND 17Z AND WILL BECOME LIGHT AND
VARIABLE LATE THIS AFTERNOON AND EARLY THIS EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...JRM
LONG TERM....JRM/JTL
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
559 AM EST THU MAR 8 2012
.SYNOPSIS...
ISSUED AT 537 AM EST THU MAR 8 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH AXIS
FROM NW ONTARIO THROUGH WRN MN INTO ERN NEBRASKA. A BAND OF LIGHT
SNOW MOVING QUICKLY THROUGH THE ERN CWA WAS SUPPORTED BY 700-600 MB
FGEN BEHIND THE COLD FRONT THAT EXITED UPPER MI TO THE SE.
OTHERWISE...JUST A FEW FLURRIES REMAINED OVER CNTRL UPPER MI. AN
UPSTREAM SHRTWV WAS MOVING FROM SE SASK TOWARD SRN MANITOBA. AT THE
SFC..NW WINDS PREVAILED BTWN A TROUGH FROM QUEBEC TO LAKE HURON AND
A RIDGFROM THE NRN PLAINS INTO NW ONTARIO. THE CLIPPER LOW
ASSOCIATED WITH THE CLIPPER SHRTWVWAS LOCATED OVER N CNTRL MANTIOBA
WITH A TRAILING COLD FRONT TO THE SW.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 537 AM EST THU MAR 8 2012
TODAY...EXPECT THE MID LEVEL TROUGH MOVING INTO THE AREA BY
AFTERNOON TO BE REINFORCED BY THE SASK SHRTWV BY LATE TODAY. THE
COMBINATION OF INCREASING 700-500 MB QVECTOR CONV...DEEPER
MOISTURE...DAYTIME HEATING AND STEEP 900-700 MB LAPSE RATES NEAR 8
C/KM WILL SUPPORT SCT SHSN DEVELOPMENT THIS AFTERNOON WHICH WILL
INCREASE IN COVERAGE AND INTENSITY LATE.
TONIGHT...SHSN WILL TRANSITION TO LES AS COLDER AIR ARRIVES
(850 MB TEMPS ARE FCST TO DROP INTO THE -14C TO -18C RANGE) AND WINDS
VEER TO THE NW. AS THE WINDS VEER THE STRONGER LOW LEVEL CONV WILL
SHIFT FROM WRN UPPER MI INTO THE NE CWA E OF MARQUETTE. WITH
FAVORABLE 850-700 MB MOISTURE AND INVERSION HEIGHTS TO NEAR 10K
FT...SOME STRONGER SNOWBANDS MAY DEVELOP WITH BRIEF HEAVY SNOW.
HOWEVER...GIVEN THE SHIFTING LOCATION OF THE BANDS...OVERALL
ACCUMULATIONS SHOULD STILL REMAIN IN THE 1 TO 3 INCH RANGE. WITH THE
LONGER FETCH INTO THE EAST...SOME ISOLATED HIGHER AMOUNTS TO AROUND 4
INCHES MAY BE POSSIBLE NEAR OR JUST INLAND FROM GRAND MARAIS. GUSTY
NORTHWEST WINDS INTO THE 20 TO 30 MPH RANGE NEAR LAKE SUPERIOR WILL
ALSO CAUSE AREA OF BLSN.
FRIDAY...LES WILL DIMINISH FROM THE WEST AS DRIER AIR MOVES INTO THE
REGION ALONG WITH ACYC FLOW AND LOWERING INVERSION HEIGHTS AND (AOB
4K FT). HOWEVER...ADDITIONAL AMOUNTS IN THE 1 TO 3 INCH RANGE MAY BE
POSSIBLE OVER THE EAST AS THE 850 MB THERMAL TROUGH (850 MB TEMPS
AROUND -18C) LINGERS INTO THE EARLY AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 537 AM EST THU MAR 8 2012
...RAIN FOLLOWED BY SIGNIFICANT WARM-UP EARLY-MID NEXT WEEK MAY
RESULT IN HYDRO ISSUES...
NOTE: SEE LATER PORTION OF THIS LONG TERM DISCUSSION FOR THOUGHTS ON
POSSIBLE HYDROLOGY ISSUES.
POP/WX WISE IT IS PRETTY QUIET FRIDAY NIGHT THROUGH SATURDAY NIGHT.
WARM AIR ADVECTIONS RAMPING UP AGAIN COULD LEAD TO BATCH OF LGT SNOW
OVR LK SUPERIOR AND PERHAPS THE FAR NORTHERN FRINGE OF THE CWA.
OTHERWISE JUST A PERIOD OF MID CLOUDS. MAIN STORY FRIDAY NIGHT INTO
SATURDAY WILL BE GUSTY SOUTH TO SOUTHWEST WINDS.
TREND THAT BEGAN TO APPEAR IN MODELS YESTERDAY CONTINUES TODAY. AS
HIGH PRESSURE RIDGE MOVES EAST FRIDAY NIGHT SFC TROUGH OVR CNTRL
CANADA WILL STEAMROLL EAST BY SUNRISE SATURDAY. TIGHT PRESSURE
GRADIENT ENSUES AND VERY STRONG PRESSURE FALLS /OVR 12MB IN 6 HR/
ARE FCST NORTH OF LK SUPERIOR. PATTERN SUGGESTS THAT DESPITE WARM
AIR ADVECTION REGIME...SOUTH TO SOUTHWEST WINDS COULD BECOME QUITE
GUSTY. FCST SOUNDINGS INDICATE A LOT OF WIND JUST ABOVE SFC /50+ KTS
AT 925MB PER GFS/ECMWF/NAM/ BUT IT IS STABLE. BLYR WINDS USUALLY DO
A GOOD JOB HIGHLIGHTING HOW STRONG WINDS COULD GET AND THIS OUTPUT
POINTS TO SOLID 35-40 KTS. GALES OVR LK SUPERIOR AND PROBABLY
NEARSHORE ZONES OF LK MICHIGAN GOOD BET. ALSO...GOING TO MENTION
SOME NEAR ADVY GUSTS IN HAZARDOUS WEATHER OUTLOOK FOR SOUTH SHORE OF
LK SUPERIOR. BASED ON SFC WIND DIRECTION AND WHERE CORE OF STRONGEST
WINDS IS FCST...THE SHORELINE FM BARAGA TO MARQUETTE ALONG LK
SUPERIOR WOULD SEE STRONGEST WINDS. ALSO COULD SEE STRONGER WINDS
OVR KEWEENAW COUNTY AS THAT AREA IS EXPOSED TO SOUTHERLY
FLOW...ESPECIALLY HIGHER TERRAIN AREAS. PRESSURE FALL MOVES STEADILY
TO THE EAST THROUGH THE DAY...BUT SOUNDINGS POINT TO BREEZY
CONDITIONS CONTINUING FOR MUCH OF SATURDAY AS MIXING WILL BE HIGHER
DUE TO MAINLY SUNNY SKIES. AS SOUTH WINDS KICK UP LATER FRIDAY NIGHT
TEMPS SHOULD BEGIN TO RISE OVR MUCH OF CWA. USED NON-DIURNAL TEMP
CURVE INTO SATURDAY WITH LOWS FRIDAY EVENING IN THE TEENS AND TEMPS
RISING TOWARD FREEZING BY SUNRISE SATURDAY. MIXING TO H9 ON SATURDAY
SEEMS PRETTY GOOD CONSIDERING AMOUNT OF INSOLATION EXPECTED. MIXING
THIS HIGH GAVE READINGS INTO THE 50S OVR MOST OF THE WEST HALF OF
CWA. SW WINDS WILL KEEP LK MICHIGAN AND INLAND AREAS OF EAST CWA
COOLER IN THE UPR 30S TO MID 40S.
IN THE EXTENDED...COULD BE AN ACTIVE WEATHER PERIOD OVR MUCH OF UPR
LAKES...BUT NOT NECESSARILY FM AMOUNT OF STORM SYSTEMS. RATHER...ONE
SYSTEM LOOKS TO BRING LGT MAYBE MODERATE RAIN AMOUNTS TO AREA LATER
SUNDAY THROUGH SUNDAY NIGHT THEN A VERY SIGNIFICANT WARM-UP IS IN
STILL LOOKS TO BE IN THE OFFING INTO THE MIDDLE OF NEXT WEEK. IF ALL
GOES AS PLANNED...MOST AREAS IN THE CWA BY THIS TIME NEXT WEEK WILL
HAVE LOST A MAJORITY IF NOT ALL OF THE SNOWPACK. WILL BE SOMETHING
TO MONITOR INTO NEXT WEEK AS THERE COULD BE SOME HYDRO ISSUES GIVEN
POTENTIAL TO MELT THE SNOW RATHER QUICKLY. LOW PRESSURE STILL FCST
TO LIFT FM THE PLAINS/MISSISSIPPI RIVER VALLEY INTO THE UPR LAKES
LATE SUNDAY. IN A GENERAL SENSE...THREE MAIN MODELS USED FOR THE
EXTENDED /GFS/ECMWF/CANADIAN/ ALL SHOW THIS SYSTEM IMPACTING UPR MI.
TIMING IS NOT SET THOUGH...AS LATEST ECMWF NOW BRINGS THE LOW MORE
ACROSS LATER SUNDAY NIGHT INTO MONDAY. THIS TIMING IS CLOSER TO
CANADIAN BUT STRAYS SIGNIFICANTLY FM NCEP MODELS /GFS AND NAM/. NCEP
PREFERRED SLOWER APPROACH AS THERE COULD BE SOME BLOCKING AHEAD OF
THE FEATURE. TRENDED THIS WAY IN GRIDS. HIGHEST CHANCES SUNDAY NIGHT
STILL LOOKED FINE. MAIN CHANGE TO CONSENSUS ALLBLEND APPROACH WAS TO
KEEP CHANCE POPS IN FOR ALL DAY MONDAY.
ONCE THE SYSTEM CLEARS THE AREA LATER MONDAY/MONDAY NIGHT...ATTN IS
ON POTENTIAL WARM-UP. SEEMS LIKE MORE OFTEN THAN NOT IN RECENT YEARS
WE HAVE LOST THE SNOWPACK IN THE SPRING WITH MORE OF A GRADUAL WARM
UP IN A STEADY FREEZE-THAW CYCLE /RISING ABOVE FREEZING DURING THE
DAYS BUT FALLING BLO AT NIGHT/. WE SEE HOW WHEN THIS DOES NOT WORK
WHAT CAN HAPPEN AS YESTERDAY AT THE OFFICE IN NEGAUNEE TWP WITH
HIGHS AROUND 50 DEGREES AND DWPNTS WELL INTO THE 40S...WE LOST 8
INCHES OF OUR SNOWPACK IN ONE DAY! AFTER OUR BREAK IN THE SNOWMELT
THE NEXT COUPLE DAYS...SEEMS LIKE WE COULD BE HEADING FOR SIMILAR
QUICK SNOWMELT LATE THIS WEEKEND THROUGH MID NEXT WEEK. MAIN CONCERN
WOULD BE TUESDAY AND WEDNESDAY AS ECMWF /WHICH FOR MOST PART USUALLY
LEADS WAY ON THESE TYPE OF WARM-UPS WELL OVER CLIMATOLOGY/ INDICATES
MAX TEMPS PUSHING OVER 60 DEGREES OVR AT LEAST THE WEST HALF OF THE
CWA. ALLBLEND GUIDANCE /BIASED TOWARD THE GFS/ WAS MUCH COOLER AND
WAS ADJUSTED UPWARD FOR BOTH DAYS. ECMWF ALSO INDICATES DWPNTS
RISING ABOVE 40...ESPECIALLY ON WEDNESDAY AHEAD OF WEAK TROUGH FCST
TO COME THROUGH ON THURSDAY.
A COUPLE OF CAUTIONS THOUGH. LATEST ECMWF NOW TRYING TO SHOW MORE
OF A TYPICAL SPRING LIKE MSLP PATTERN ON TUESDAY WITH POSSIBLE LAKE
BREEZES AS MAIN TROUGH REMAINS OVR PLAINS. TRIMMED TEMPS SLIGHTLY
TOWARD LK SUPERIOR SHORE FOR TUESDAY...WITH BETTER SHOT OF THE
REALLY WARM TEMPS STAYING INLAND TOWARD WI BORDER. TROUGH IS CLOSE
ENOUGH ON WEDNESDAY TO RESULT IN MAINLY SW FLOW FOR ALL AREAS AND
ALLOWING THE WARM TEMPS RIGHT TO PUSH TO THE LK SUPERIOR SHORE AS
WELL ALONG WITH DWPNTS RISING WELL ABOVE 40F. OBVIOUSLY GIVEN THIS
KIND OF MOISTURE ADVECTION AND THE MELING SNOWPACK ONGOING...SOME
STRATUS/FOG IS NOT OUT OF QUESTION WHICH WOULD IMPACT TEMPS. STILL
QUESTIONS IN SPECIFICS BUT THIS TIME FRAME COULD POSE SOME ISSUES
WITH REGARD TO RISES ON RIVES/STREAMS AND SOME AREAL FLOODING
CONCERNS IN LOW-LYING SPOTS AS WELL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 558 AM EST THU MAR 8 2012
EXPECT MAINLY MVFR CIGS TODAY WITH LOW LEVEL MOISTURE REMAINING OVER
THE AREA. AN APPROACHING DISTURBANCE/STEEP LAPSE RATES/DAYTIME
HEATING WILL LIKELY LEAD TO SCT/NMRS -SHSN LATER THIS AFTN INTO THE
EVENING HRS. MVFR CONDITIONS SHOULD GENERALLY PREVAIL...THOUGH SOME
BRIEF PERIODS OF IFR MAY OCCUR DEPENDING ON THE INTENSITY OF THE
-SHSN. SHSN WILL TRANSITION TO LES AS COLDER AIR MOVES IN TONIGHT
BUT SHOULD MAINLY AFFECT KCMX. NORTHWEST WINDS WILL ALSO INCREASE
LATE THIS EVENING AND OVERNIGHT WITH BLSN ALSO DEVELOPING AT KCMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 537 AM EST THU MAR 8 2012
A COUPLE OF PERIODS OF GALES ON THE LAKE INTO THIS WEEKEND. FIRST
GALE EVENT IS TONIGHT WITH COLD AND UNSTABLE PROFILE OVER THE LAKE.
SHOULD SEE FREQUENT GUSTS 35-40 KTS AND HAVE ISSUED GALE WARNING FOR
ALL OF LK SUPERIOR INTO EARLY FRIDAY. HAVE ALSO POSTED HEAVY FREEZING
SPRAY WARNING FOR TONIGHT. NOT OUT OF QUESTION THAT THIS MAY BE LAST
HEAVY FREEZING SPRAY EPISODE OF WINTER.
SOUTH TO SOUTHWEST GALES THEN LOOK LIKELY LATER FRIDAY NIGHT INTO
SATURDAY AS PRESSURE GRADIENT TIGHTENS OVER LK SUPERIOR. WARM AIR
ADVECTION REGIME KEEPS HIGHER STABILITY IN LOW-LEVELS...BUT THINK
THIS WILL BE OFFSET BY VERY STRONG PRESSURE FALLS SLIDING JUST NORTH
OF LK SUPERIOR. SETUP USUALLY RESULTS IN STRONGEST WINDS OVER
EASTERN HALF OF LK SUPERIOR. WINDS SETTLE DOWN CONSIDERABLY BY LATER
SATURDAY NIGHT INTO SUNDAY. WIND DIRECTION LATER SUNDAY INTO MONDAY
WILL BE HIGHLY DEPENDANT ON TRACK OF APPROACHING LOW PRESSURE SYSTEM
FM CENTRAL PLAINS. EXPECT WINDS TO REMAIN LESS THAN 30 KTS AS THE
SYSTEM MOVES THROUGH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 4 AM TO 11 AM EST FRIDAY FOR LSZ267.
GALE WARNING FROM 1 AM TO 11 AM EST FRIDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING FROM 7 PM EST /6 PM CST/ THIS
EVENING TO 7 AM EST /6 AM CST/ FRIDAY FOR LSZ162-240>245-
248-263>265.
GALE WARNING FROM 10 PM EST /9 PM CST/ THIS EVENING TO 6 AM EST
/5 AM CST/ FRIDAY FOR LSZ162-263.
GALE WARNING FROM MIDNIGHT TONIGHT TO 8 AM EST FRIDAY FOR LSZ264-
265.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
539 AM EST THU MAR 8 2012
.SYNOPSIS...
ISSUED AT 537 AM EST THU MAR 8 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH AXIS
FROM NW ONTARIO THROUGH WRN MN INTO ERN NEBRASKA. A BAND OF LIGHT
SNOW MOVING QUICKLY THROUGH THE ERN CWA WAS SUPPORTED BY 700-600 MB
FGEN BEHIND THE COLD FRONT THAT EXITED UPPER MI TO THE SE.
OTHERWISE...JUST A FEW FLURRIES REMAINED OVER CNTRL UPPER MI. AN
UPSTREAM SHRTWV WAS MOVING FROM SE SASK TOWARD SRN MANITOBA. AT THE
SFC..NW WINDS PREVAILED BTWN A TROUGH FROM QUEBEC TO LAKE HURON AND
A RIDGFROM THE NRN PLAINS INTO NW ONTARIO. THE CLIPPER LOW
ASSOCIATED WITH THE CLIPPER SHRTWVWAS LOCATED OVER N CNTRL MANTIOBA
WITH A TRAILING COLD FRONT TO THE SW.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 537 AM EST THU MAR 8 2012
TODAY...EXPECT THE MID LEVEL TROUGH MOVING INTO THE AREA BY
AFTERNOON TO BE REINFORCED BY THE SASK SHRTWV BY LATE TODAY. THE
COMBINATION OF INCREASING 700-500 MB QVECTOR CONV...DEEPER
MOISTURE...DAYTIME HEATING AND STEEP 900-700 MB LAPSE RATES NEAR 8
C/KM WILL SUPPORT SCT SHSN DEVELOPMENT THIS AFTERNOON WHICH WILL
INCREASE IN COVERAGE AND INTENSITY LATE.
TONIGHT...SHSN WILL TRANSITION TO LES AS COLDER AIR ARRIVES
(850 MB TEMPS ARE FCST TO DROP INTO THE -14C TO -18C RANGE) AND WINDS
VEER TO THE NW. AS THE WINDS VEER THE STRONGER LOW LEVEL CONV WILL
SHIFT FROM WRN UPPER MI INTO THE NE CWA E OF MARQUETTE. WITH
FAVORABLE 850-700 MB MOISTURE AND INVERSION HEIGHTS TO NEAR 10K
FT...SOME STRONGER SNOWBANDS MAY DEVELOP WITH BRIEF HEAVY SNOW.
HOWEVER...GIVEN THE SHIFTING LOCATION OF THE BANDS...OVERALL
ACCUMULATIONS SHOULD STILL REMAIN IN THE 1 TO 3 INCH RANGE. WITH THE
LONGER FETCH INTO THE EAST...SOME ISOLATED HIGHER AMOUNTS TO AROUND 4
INCHES MAY BE POSSIBLE NEAR OR JUST INLAND FROM GRAND MARAIS. GUSTY
NORTHWEST WINDS INTO THE 20 TO 30 MPH RANGE NEAR LAKE SUPERIOR WILL
ALSO CAUSE AREA OF BLSN.
FRIDAY...LES WILL DIMINISH FROM THE WEST AS DRIER AIR MOVES INTO THE
REGION ALONG WITH ACYC FLOW AND LOWERING INVERSION HEIGHTS AND (AOB
4K FT). HOWEVER...ADDITIONAL AMOUNTS IN THE 1 TO 3 INCH RANGE MAY BE
POSSIBLE OVER THE EAST AS THE 850 MB THERMAL TROUGH (850 MB TEMPS
AROUND -18C) LINGERS INTO THE EARLY AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 537 AM EST THU MAR 8 2012
...RAIN FOLLOWED BY SIGNIFICANT WARM-UP EARLY-MID NEXT WEEK MAY
RESULT IN HYDRO ISSUES...
NOTE: SEE LATER PORTION OF THIS LONG TERM DISCUSSION FOR THOUGHTS ON
POSSIBLE HYDROLOGY ISSUES.
POP/WX WISE IT IS PRETTY QUIET FRIDAY NIGHT THROUGH SATURDAY NIGHT.
WARM AIR ADVECTIONS RAMPING UP AGAIN COULD LEAD TO BATCH OF LGT SNOW
OVR LK SUPERIOR AND PERHAPS THE FAR NORTHERN FRINGE OF THE CWA.
OTHERWISE JUST A PERIOD OF MID CLOUDS. MAIN STORY FRIDAY NIGHT INTO
SATURDAY WILL BE GUSTY SOUTH TO SOUTHWEST WINDS.
TREND THAT BEGAN TO APPEAR IN MODELS YESTERDAY CONTINUES TODAY. AS
HIGH PRESSURE RIDGE MOVES EAST FRIDAY NIGHT SFC TROUGH OVR CNTRL
CANADA WILL STEAMROLL EAST BY SUNRISE SATURDAY. TIGHT PRESSURE
GRADIENT ENSUES AND VERY STRONG PRESSURE FALLS /OVR 12MB IN 6 HR/
ARE FCST NORTH OF LK SUPERIOR. PATTERN SUGGESTS THAT DESPITE WARM
AIR ADVECTION REGIME...SOUTH TO SOUTHWEST WINDS COULD BECOME QUITE
GUSTY. FCST SOUNDINGS INDICATE A LOT OF WIND JUST ABOVE SFC /50+ KTS
AT 925MB PER GFS/ECMWF/NAM/ BUT IT IS STABLE. BLYR WINDS USUALLY DO
A GOOD JOB HIGHLIGHTING HOW STRONG WINDS COULD GET AND THIS OUTPUT
POINTS TO SOLID 35-40 KTS. GALES OVR LK SUPERIOR AND PROBABLY
NEARSHORE ZONES OF LK MICHIGAN GOOD BET. ALSO...GOING TO MENTION
SOME NEAR ADVY GUSTS IN HAZARDOUS WEATHER OUTLOOK FOR SOUTH SHORE OF
LK SUPERIOR. BASED ON SFC WIND DIRECTION AND WHERE CORE OF STRONGEST
WINDS IS FCST...THE SHORELINE FM BARAGA TO MARQUETTE ALONG LK
SUPERIOR WOULD SEE STRONGEST WINDS. ALSO COULD SEE STRONGER WINDS
OVR KEWEENAW COUNTY AS THAT AREA IS EXPOSED TO SOUTHERLY
FLOW...ESPECIALLY HIGHER TERRAIN AREAS. PRESSURE FALL MOVES STEADILY
TO THE EAST THROUGH THE DAY...BUT SOUNDINGS POINT TO BREEZY
CONDITIONS CONTINUING FOR MUCH OF SATURDAY AS MIXING WILL BE HIGHER
DUE TO MAINLY SUNNY SKIES. AS SOUTH WINDS KICK UP LATER FRIDAY NIGHT
TEMPS SHOULD BEGIN TO RISE OVR MUCH OF CWA. USED NON-DIURNAL TEMP
CURVE INTO SATURDAY WITH LOWS FRIDAY EVENING IN THE TEENS AND TEMPS
RISING TOWARD FREEZING BY SUNRISE SATURDAY. MIXING TO H9 ON SATURDAY
SEEMS PRETTY GOOD CONSIDERING AMOUNT OF INSOLATION EXPECTED. MIXING
THIS HIGH GAVE READINGS INTO THE 50S OVR MOST OF THE WEST HALF OF
CWA. SW WINDS WILL KEEP LK MICHIGAN AND INLAND AREAS OF EAST CWA
COOLER IN THE UPR 30S TO MID 40S.
IN THE EXTENDED...COULD BE AN ACTIVE WEATHER PERIOD OVR MUCH OF UPR
LAKES...BUT NOT NECESSARILY FM AMOUNT OF STORM SYSTEMS. RATHER...ONE
SYSTEM LOOKS TO BRING LGT MAYBE MODERATE RAIN AMOUNTS TO AREA LATER
SUNDAY THROUGH SUNDAY NIGHT THEN A VERY SIGNIFICANT WARM-UP IS IN
STILL LOOKS TO BE IN THE OFFING INTO THE MIDDLE OF NEXT WEEK. IF ALL
GOES AS PLANNED...MOST AREAS IN THE CWA BY THIS TIME NEXT WEEK WILL
HAVE LOST A MAJORITY IF NOT ALL OF THE SNOWPACK. WILL BE SOMETHING
TO MONITOR INTO NEXT WEEK AS THERE COULD BE SOME HYDRO ISSUES GIVEN
POTENTIAL TO MELT THE SNOW RATHER QUICKLY. LOW PRESSURE STILL FCST
TO LIFT FM THE PLAINS/MISSISSIPPI RIVER VALLEY INTO THE UPR LAKES
LATE SUNDAY. IN A GENERAL SENSE...THREE MAIN MODELS USED FOR THE
EXTENDED /GFS/ECMWF/CANADIAN/ ALL SHOW THIS SYSTEM IMPACTING UPR MI.
TIMING IS NOT SET THOUGH...AS LATEST ECMWF NOW BRINGS THE LOW MORE
ACROSS LATER SUNDAY NIGHT INTO MONDAY. THIS TIMING IS CLOSER TO
CANADIAN BUT STRAYS SIGNIFICANTLY FM NCEP MODELS /GFS AND NAM/. NCEP
PREFERRED SLOWER APPROACH AS THERE COULD BE SOME BLOCKING AHEAD OF
THE FEATURE. TRENDED THIS WAY IN GRIDS. HIGHEST CHANCES SUNDAY NIGHT
STILL LOOKED FINE. MAIN CHANGE TO CONSENSUS ALLBLEND APPROACH WAS TO
KEEP CHANCE POPS IN FOR ALL DAY MONDAY.
ONCE THE SYSTEM CLEARS THE AREA LATER MONDAY/MONDAY NIGHT...ATTN IS
ON POTENTIAL WARM-UP. SEEMS LIKE MORE OFTEN THAN NOT IN RECENT YEARS
WE HAVE LOST THE SNOWPACK IN THE SPRING WITH MORE OF A GRADUAL WARM
UP IN A STEADY FREEZE-THAW CYCLE /RISING ABOVE FREEZING DURING THE
DAYS BUT FALLING BLO AT NIGHT/. WE SEE HOW WHEN THIS DOES NOT WORK
WHAT CAN HAPPEN AS YESTERDAY AT THE OFFICE IN NEGAUNEE TWP WITH
HIGHS AROUND 50 DEGREES AND DWPNTS WELL INTO THE 40S...WE LOST 8
INCHES OF OUR SNOWPACK IN ONE DAY! AFTER OUR BREAK IN THE SNOWMELT
THE NEXT COUPLE DAYS...SEEMS LIKE WE COULD BE HEADING FOR SIMILAR
QUICK SNOWMELT LATE THIS WEEKEND THROUGH MID NEXT WEEK. MAIN CONCERN
WOULD BE TUESDAY AND WEDNESDAY AS ECMWF /WHICH FOR MOST PART USUALLY
LEADS WAY ON THESE TYPE OF WARM-UPS WELL OVER CLIMATOLOGY/ INDICATES
MAX TEMPS PUSHING OVER 60 DEGREES OVR AT LEAST THE WEST HALF OF THE
CWA. ALLBLEND GUIDANCE /BIASED TOWARD THE GFS/ WAS MUCH COOLER AND
WAS ADJUSTED UPWARD FOR BOTH DAYS. ECMWF ALSO INDICATES DWPNTS
RISING ABOVE 40...ESPECIALLY ON WEDNESDAY AHEAD OF WEAK TROUGH FCST
TO COME THROUGH ON THURSDAY.
A COUPLE OF CAUTIONS THOUGH. LATEST ECMWF NOW TRYING TO SHOW MORE
OF A TYPICAL SPRING LIKE MSLP PATTERN ON TUESDAY WITH POSSIBLE LAKE
BREEZES AS MAIN TROUGH REMAINS OVR PLAINS. TRIMMED TEMPS SLIGHTLY
TOWARD LK SUPERIOR SHORE FOR TUESDAY...WITH BETTER SHOT OF THE
REALLY WARM TEMPS STAYING INLAND TOWARD WI BORDER. TROUGH IS CLOSE
ENOUGH ON WEDNESDAY TO RESULT IN MAINLY SW FLOW FOR ALL AREAS AND
ALLOWING THE WARM TEMPS RIGHT TO PUSH TO THE LK SUPERIOR SHORE AS
WELL ALONG WITH DWPNTS RISING WELL ABOVE 40F. OBVIOUSLY GIVEN THIS
KIND OF MOISTURE ADVECTION AND THE MELING SNOWPACK ONGOING...SOME
STRATUS/FOG IS NOT OUT OF QUESTION WHICH WOULD IMPACT TEMPS. STILL
QUESTIONS IN SPECIFICS BUT THIS TIME FRAME COULD POSE SOME ISSUES
WITH REGARD TO RISES ON RIVES/STREAMS AND SOME AREAL FLOODING
CONCERNS IN LOW-LYING SPOTS AS WELL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 537 AM EST THU MAR 8 2012
WITH DRIER AIR WORKING INTO THE AREA BEHIND COLD FRONT...LOW
MVFR/IFR CIGS AT KIWD/KCMX/KSAW SHOULD RISE TO THE UPPER MVFR RANGE
OVER THE NEXT SEVERAL HRS...AND NOT OUT OF THE QUESTION THAT CIGS
COULD RISE TO VFR LATER IN THE NIGHT. ONGOING -SN WILL DIMINISH AND
SHOULD NOT POSE MUCH VIS RESTRICTION LATER IN THE NIGHT AS WELL.
APPROACHING DISTURBANCE/STEEP LAPSE RATES/DAYTIME HEATING WILL
LIKELY LEAD TO SCT/NMRS -SHSN LATER THIS AFTN INTO THE EVENING HRS.
MVFR CONDITIONS SHOULD GENERALLY PREVAIL...THOUGH SOME BRIEF PERIODS
OF IFR MAY OCCUR DEPENDING ON INTENSITY OF -SHSN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 537 AM EST THU MAR 8 2012
SOUTH TO SOUTHWEST GALES LOOKING LIKELY LATER FRIDAY NIGHT INTO
SATURDAY AS PRESSURE GRADIENT TIGHTENS OVER LK SUPERIOR. WARM AIR
ADVECTION REGIME KEEPS HIGHER STABILITY IN LOW-LEVELS...BUT THINK
THIS WILL BE OFFSET BY VERY STRONG PRESSURE FALLS SLIDING JUST NORTH
OF LK SUPERIOR. SETUP USUALLY RESULTS IN STRONGEST WINDS OVER
EASTERN HALF OF LK SUPERIOR. WINDS SETTLE DOWN CONSIDERABLY BY LATER
SATURDAY NIGHT INTO SUNDAY. WIND DIRECTION LATER SUNDAY INTO MONDAY
WILL BE HIGHLY DEPENDANT ON TRACK OF APPROACHING LOW PRESSURE SYSTEM
FM CENTRAL PLAINS. EXPECT WINDS TO REMAIN LESS THAN 30 KTS AS THE
SYSTEM MOVES THROUGH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 4 AM TO 11 AM EST FRIDAY FOR LSZ267.
GALE WARNING FROM 1 AM TO 11 AM EST FRIDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING FROM 7 PM EST /6 PM CST/ THIS
EVENING TO 7 AM EST /6 AM CST/ FRIDAY FOR LSZ162-240>245-
248-263>265.
GALE WARNING FROM 10 PM EST /9 PM CST/ THIS EVENING TO 6 AM EST
/5 AM CST/ FRIDAY FOR LSZ162-263.
GALE WARNING FROM MIDNIGHT TONIGHT TO 8 AM EST FRIDAY FOR LSZ264-
265.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1000 AM CST THU MAR 8 2012
.UPDATE...
ADDED SCATTERED SNOW SHOWERS ACROSS THE SRN COUNTIES THIS MORNING
TO ACCOUNT FOR A SMALL CLUSTER OF SNOW SHOWERS MOVING FROM E-CNTRL
MN INTO WI. STILL ANTICIPATING THE CONVECTIVE SNOW SHOWERS TO
DEVELOP THIS AFTERNOON...AND AFTER LOOKING AT THE LATEST HIGH- RES
SHORT TERM MODELS...LOOKS VERY UNSTABLE IN THE LOW AND MID
LEVELS... WITH STEEP LAPSE RATES AND 50-80 J/KG OF LOW-LVL
CAPE...AND ALSO VERY SUPPORTIVE ALOFT FOR A QUICK INCH OF SNOW
ACCUMULATION. WINDS WILL INCREASE FROM THE NW THIS AFTERNOON...AND
COMBINE WITH THE SNOW SHOWERS TO PRODUCE AREAS OF BLOWING SNOW.
VISIBILITIES COULD BE REDUCED TO A MILE OR LESS AT TIMES IN THE
BLOWING SNOW. A STRONG 140KT JET WILL PUSH IN FROM THE NW...WITH
THE NORTHLAND IN THE LEFT EXIT REGION...ALSO A STRONG 500MB VORT
MAX WILL ADVECT INTO THE REGION TO HELP WITH VERTICAL MOTION.
SYSTEM SHOULD MOVE THROUGH VERY RAPIDLY AS HIGH PRESSURE BUILDS IN
ON THE BACK SIDE.
&&
.PREV DISCUSSION... /ISSUED 654 AM CST THU MAR 8 2012/
AVIATION.../12Z TAF ISSUANCE/
ANOTHER COLD FRONT WILL TRACK SEWD ACROSS THE NORTHLAND THIS
AFTERNOON AND EVENING...BRINGING INCREASING CLOUD COVER AND AREAS
OF LIGHT SNOW TO THE REGION. CIGS AND VSBYS ASSOCIATED WITH THE
FROPA WILL BE IN THE MVFR/LOW VFR RANGE. THE SNOW SHOULD END LATE
THIS EVENING OVER OVERNIGHT AND SKIES WILL SCTR OUT.
PREV DISCUSSION... /ISSUED 403 AM CST THU MAR 8 2012/
SHORT TERM...THE SHORT TERM FOCUS IS ON WINDS AND SNOW SHOWER
POTENTIAL ACROSS THE NORTHLAND.
AT 330 AM...FAIRLY WIDESPREAD CLOUD COVER WAS MOVING ACROSS THE
NORTHLAND ALTHOUGH THERE WERE SEVERAL AREAS OF THIN CLOUDS.
TEMPERATURES RANGED FROM THE UPPER 20S IN PORTIONS OF NW WI...TO
NEAR 10 ABOVE FAR NORTHWEST.
NORTHWEST FLOW WILL PERSIST ACROSS THE NORTHLAND TODAY. STRONG CAA
WILL BECOME FAIRLY NEUTRAL THROUGHOUT THE DAY. THE NAM INDICATES
THAT AT LEAST A COUPLE SHORTWAVES WILL MOVE THROUGH THE REGION IN
NW FLOW TODAY. EACH WILL BE CAPABLE OF GENERATING SOME SNOW
SHOWERS...BUT THE BEST CHANCE SHOULD BE ACROSS THE NORTH IN THE
AFTERNOON AND EARLY EVENING. WITH COLD AIR ALOFT AND SOME SURFACE
HEATING BETWEEN SNOW SHOWERS...THINK SOME OF THE SNOW SHOWERS
COULD BE FAIRLY STRONG THIS AFTERNOON...EVEN BRINGING SOME GUSTY
WINDS WITH THE SNOW SHOWERS.
THE BIGGER STORY FOR TODAY MAY BE THE STRONG WINDS EXPECTED TO
MOVE INTO THE CWA DURING THE AFTERNOON AND EVENING. HAVE BROUGHT
WINDS UP QUITE A BIT. THE RUC SHOWS STRONG WINDS ALOFT MIXING DOWN
TO THE SURFACE. THE FORECAST SOUNDINGS FOR DULUTH INDICATE 40-50
KNOTS WORKING ITS WAY TO JUST ABOVE THE SURFACE. AS A RESULT...WE
COULD EASILY SEE SOME 20 TO 30 MPH SUSTAINED WINDS THIS AFTERNOON
WITH HIGHER GUSTS AS WELL. WINDS WILL THEN DECREASED OVERNIGHT AS
SKIES CLEAR FROM THE WEST. HAVE DROPPED TEMPS CONSIDERABLY FOR
TONIGHT...CLOSER TO THE MAV GUIDANCE. THIS SHOULD RESULT IN
TEMPERATURES DROPPING BELOW ZERO IN THE NORTH.
FRIDAY SHOULD BE A BIT WARMER...AS WAA PUSHES ACROSS THE REGION.
SHOULD BE SOMEWHAT OF AN INCREASE IN CLOUDS...ESPECIALLY IN THE
NORTH. THINK MOST OF THE PRECIPITATION SHOULD REMAIN IN CANADA.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY. THE EXTENDED
FORECAST PERIOD WILL START OUT DRY AND MILD UNDER WITH A UPPER
RIDGE BUILDING OVER THE WRN GREAT LAKES DUE TO STRONG SWRLY FLOW
IN THE LOW-LEVELS. HOWEVER THE RIDGE WILL GIVE WAY TO A LOW
PRESSURE SYSTEM DEVELOPING OVER THE CNTL PLAINS WHICH IS PROGGED
TO LIFT NEWD OVER THE GREAT LAKES SUNDAY INTO MONDAY. THERE ARE
STILL SOME SIGNIFICANT DIFFERENCES BETWEEN THE VARIOUS NWP MODEL
SOLUTIONS...WITH THE NAM/GFS TAKING THE LOW OFF TO THE SOUTH AND
EAST OF OUR CWA...WHILE THE ECMWF/GEM BRING IT RIGHT OVER THE
NORTHLAND. DUE TO THESE DIFFERENCES...WE WILL KEEP POPS IN THE
CHANCE CATEGORY ATTM. PRECIP TYPE SHOULD BE MAINLY RAIN DUE TO THE
WARM AIRMASS IN PLACE ACROSS THE UPPER MIDWEST. BUT IF THE DYNAMIC
LIFT IS STRONG ENOUGH...THERE COULD BE A WINTRY MIX SUNDAY NIGHT
AND MONDAY MORNING. AFTER THE LOW MOVES OFF TO THE EAST...AN
UNSEASONABLY WARM AND DRY PATTERN WILL DEVELOP ACROSS THE
NORTHLAND NEXT WEEK AS SOUTHWEST FLOW DOMINATES ACROSS THE CTRL
PART OF THE COUNTRY THROUGH WEDNESDAY.
AVIATION.../06Z TAF ISSUANCE/
MVFR AND ISOLATED IFR IN CLOUDS AND SNOW IN A FRONTAL BAND SHOULD
MOVE OUT OF THE IWD AND GOGEBIC RANGE AREA LATE TONIGHT. MN NORTH
SHORE AND REST OF NORTHWEST WISCONSIN...MVFR IN CLOUDS IMPROVING
TO VFR SCATTERED WITH AREAS OF BROKEN CLOUDS BY DAY BREAK THURSDAY
MORNING. THE REST OF NORTHEAST MN...VFR THROUGH EARLY MORNING.
AREAS OF LOW-END VFR IN CLOUDS WILL DEVELOP MIDMORNING ACROSS
COASTAL WI AND NORTH OF ROUTE 2 IN NORTHEAST MN AFTER MIDMORNING
THURSDAY...AND PERSIST TILL LATE THURSDAY AFTERNOON. VFR CLEAR
BEGINNING THURSDAY EVENING. BRISK NORTHWEST WINDS...GUSTING TO 30
MPH...WILL CONTINUE INTO LATE THURSDAY AFTERNOON...AND SUBSIDE
DURING THURSDAY EVENING.
&&
.POINT TEMPS/POPS...
DLH 31 7 29 25 / 30 30 0 10
INL 31 -5 32 22 / 40 20 10 10
BRD 34 5 35 29 / 30 10 0 0
HYR 33 5 33 27 / 30 30 0 10
ASX 34 10 30 25 / 30 30 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...TENTINGER
AREA FORECAST DISCUSSION
NWS DULUTH MN
654 AM CST THU MAR 8 2012
.AVIATION.../12Z TAF ISSUANCE/
ANOTHER COLD FRONT WILL TRACK SEWD ACROSS THE NORTHLAND THIS
AFTERNOON AND EVENING...BRINGING INCREASING CLOUD COVER AND AREAS
OF LIGHT SNOW TO THE REGION. CIGS AND VSBYS ASSOCIATED WITH THE
FROPA WILL BE IN THE MVFR/LOW VFR RANGE. THE SNOW SHOULD END LATE
THIS EVENING OVER OVERNIGHT AND SKIES WILL SCTR OUT.
&&
.PREV DISCUSSION... /ISSUED 403 AM CST THU MAR 8 2012/
SHORT TERM...THE SHORT TERM FOCUS IS ON WINDS AND SNOW SHOWER
POTENTIAL ACROSS THE NORTHLAND.
AT 330 AM...FAIRLY WIDESPREAD CLOUD COVER WAS MOVING ACROSS THE
NORTHLAND ALTHOUGH THERE WERE SEVERAL AREAS OF THIN CLOUDS.
TEMPERATURES RANGED FROM THE UPPER 20S IN PORTIONS OF NW WI...TO
NEAR 10 ABOVE FAR NORTHWEST.
NORTHWEST FLOW WILL PERSIST ACROSS THE NORTHLAND TODAY. STRONG CAA
WILL BECOME FAIRLY NEUTRAL THROUGHOUT THE DAY. THE NAM INDICATES
THAT AT LEAST A COUPLE SHORTWAVES WILL MOVE THROUGH THE REGION IN
NW FLOW TODAY. EACH WILL BE CAPABLE OF GENERATING SOME SNOW
SHOWERS...BUT THE BEST CHANCE SHOULD BE ACROSS THE NORTH IN THE
AFTERNOON AND EARLY EVENING. WITH COLD AIR ALOFT AND SOME SURFACE
HEATING BETWEEN SNOW SHOWERS...THINK SOME OF THE SNOW SHOWERS
COULD BE FAIRLY STRONG THIS AFTERNOON...EVEN BRINGING SOME GUSTY
WINDS WITH THE SNOW SHOWERS.
THE BIGGER STORY FOR TODAY MAY BE THE STRONG WINDS EXPECTED TO
MOVE INTO THE CWA DURING THE AFTERNOON AND EVENING. HAVE BROUGHT
WINDS UP QUITE A BIT. THE RUC SHOWS STRONG WINDS ALOFT MIXING DOWN
TO THE SURFACE. THE FORECAST SOUNDINGS FOR DULUTH INDICATE 40-50
KNOTS WORKING ITS WAY TO JUST ABOVE THE SURFACE. AS A RESULT...WE
COULD EASILY SEE SOME 20 TO 30 MPH SUSTAINED WINDS THIS AFTERNOON
WITH HIGHER GUSTS AS WELL. WINDS WILL THEN DECREASED OVERNIGHT AS
SKIES CLEAR FROM THE WEST. HAVE DROPPED TEMPS CONSIDERABLY FOR
TONIGHT...CLOSER TO THE MAV GUIDANCE. THIS SHOULD RESULT IN
TEMPERATURES DROPPING BELOW ZERO IN THE NORTH.
FRIDAY SHOULD BE A BIT WARMER...AS WAA PUSHES ACROSS THE REGION.
SHOULD BE SOMEWHAT OF AN INCREASE IN CLOUDS...ESPECIALLY IN THE
NORTH. THINK MOST OF THE PRECIPITATION SHOULD REMAIN IN CANADA.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY. THE EXTENDED
FORECAST PERIOD WILL START OUT DRY AND MILD UNDER WITH A UPPER
RIDGE BUILDING OVER THE WRN GREAT LAKES DUE TO STRONG SWRLY FLOW
IN THE LOW-LEVELS. HOWEVER THE RIDGE WILL GIVE WAY TO A LOW
PRESSURE SYSTEM DEVELOPING OVER THE CNTL PLAINS WHICH IS PROGGED
TO LIFT NEWD OVER THE GREAT LAKES SUNDAY INTO MONDAY. THERE ARE
STILL SOME SIGNIFICANT DIFFERENCES BETWEEN THE VARIOUS NWP MODEL
SOLUTIONS...WITH THE NAM/GFS TAKING THE LOW OFF TO THE SOUTH AND
EAST OF OUR CWA...WHILE THE ECMWF/GEM BRING IT RIGHT OVER THE
NORTHLAND. DUE TO THESE DIFFERENCES...WE WILL KEEP POPS IN THE
CHANCE CATEGORY ATTM. PRECIP TYPE SHOULD BE MAINLY RAIN DUE TO THE
WARM AIRMASS IN PLACE ACROSS THE UPPER MIDWEST. BUT IF THE DYNAMIC
LIFT IS STRONG ENOUGH...THERE COULD BE A WINTRY MIX SUNDAY NIGHT
AND MONDAY MORNING. AFTER THE LOW MOVES OFF TO THE EAST...AN
UNSEASONABLY WARM AND DRY PATTERN WILL DEVELOP ACROSS THE
NORTHLAND NEXT WEEK AS SOUTHWEST FLOW DOMINATES ACROSS THE CTRL
PART OF THE COUNTRY THROUGH WEDNESDAY.
AVIATION.../06Z TAF ISSUANCE/
MVFR AND ISOLATED IFR IN CLOUDS AND SNOW IN A FRONTAL BAND SHOULD
MOVE OUT OF THE IWD AND GOGEBIC RANGE AREA LATE TONIGHT. MN NORTH
SHORE AND REST OF NORTHWEST WISCONSIN...MVFR IN CLOUDS IMPROVING
TO VFR SCATTERED WITH AREAS OF BROKEN CLOUDS BY DAY BREAK THURSDAY
MORNING. THE REST OF NORTHEAST MN...VFR THROUGH EARLY MORNING.
AREAS OF LOW-END VFR IN CLOUDS WILL DEVELOP MIDMORNING ACROSS
COASTAL WI AND NORTH OF ROUTE 2 IN NORTHEAST MN AFTER MIDMORNING
THURSDAY...AND PERSIST TILL LATE THURSDAY AFTERNOON. VFR CLEAR
BEGINNING THURSDAY EVENING. BRISK NORTHWEST WINDS...GUSTING TO 30
MPH...WILL CONTINUE INTO LATE THURSDAY AFTERNOON...AND SUBSIDE
DURING THURSDAY EVENING.
&&
.POINT TEMPS/POPS...
DLH 32 7 29 25 / 30 30 0 10
INL 28 -5 32 22 / 40 20 10 10
BRD 34 5 35 29 / 30 10 0 0
HYR 35 5 33 27 / 30 30 0 10
ASX 34 10 30 25 / 30 30 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
AVIATION...BERDES
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
620 AM CST THU MAR 8 2012
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
MAIN CONCERN WILL BE WINDS THURSDAY AFTERNOON AND EVENING WITH COLD
AIR ADVECTION. THE NEXT POTENTIAL WEATHER MAKER IS THE EMERGENCE OF
THE CUTOFF LOW EARLY NEXT WEEK. FINALLY...THERMAL RIDGING WILL ALLOW
NEAR RECORD BREAKING HIGH TEMPERATURES THROUGH MID WEEK.
TODAY THROUGH TONIGHT...LATEST WV IMAGERY SHOWS TWO SHORTWAVES
ACROSS THE US/CANADA BORDER. THE FIRST ONE IS LOCATED OVER NORTH
DAKOTA...AND IS SPAWNING A FEW LIGHT SNOW SHOWERS OVER THE RED RIVER
VALLEY. THIS FEATURE WILL CONTINUE TO HEAD SOUTHEAST...SO HAVE
FLURRIES ACROSS THE NORTHERN TIERS. THE SECOND MORE POTENT WAVE IS
STREAMING DOWN FROM SASKATCHEWAN...AND THIS WILL CONTINUE TO
STRENGTHEN AS IT HEADS TOWARD THE GREAT LAKES REGION. THE STRONGEST
FORCING ASSOCIATED WITH PV ANOMALY WILL BE ACROSS NORTHERN
MINNESOTA...BUT EXPECT A FEW SNOW SHOWERS BY THE AFTERNOON.
SOUNDINGS SHOW DEEP MIXING WITH 35 TO 40KTS ATOP THE MIXED
LAYER...SO HAVE A WIND ADVISORY FOR NORTHWESTERN CWA. THIS IS ALSO
SUPPORTED BY THE ISALLOBARIC MAPS SHOWING THE PRESSURE RISES
ASSOCIATED WITH THE SUBSIDENCE ON THE BACK SIDE OF THE PASSING
SHORTWAVE. WINDS SHOULD REMAIN STRONG THROUGH THE EVENING
HOURS...BEFORE TAPERING OFF THURSDAY NIGHT.
FRIDAY THROUGH WEDNESDAY...UPPER LEVEL RIDGING WILL REMAIN IN PLACE
ACROSS THE MIDWEST ALLOWING FOR SOUTHWEST FLOW AND LOW LEVEL WARM
AIR ADVECTION. THE ONLY CAVEAT IS A CUT OFF LOW CURRENTLY LOCATED
ACROSS THE 4CORNERS REGION THAT IS EXPECTED TO TRACK NORTHEAST FOR
THE WEEKEND. THERE IS STILL SOME DISAGREEMENT ON WHEN AND WHERE
THIS LOW GO...WITH THE ECMWF 08.00 CONSIDERABLY SLOWER THAN PREVIOUS
RUN...AS WELL AS THE LATEST GFS AND GEM. THEREFORE TRENDED SLOWER
WITH THE ONSET OF PRECIPITATION AND KEPT SUNDAY AND MONDAY HIGH
TEMPS NEAR GUIDANCE WITH THE POSSIBILITY OF CLOUD COVER. ASIDE FROM
THIS SOLE CHANCE OF WIDESPREAD PRECIP...THE EXTENDED WILL BE DRY AND
WARM. HAVE INCREASED THE TEMPS FOR SATURDAY...AND TUESDAY THROUGH
THURSDAY AS SOUTHWESTERLY WINDS AND CLEAR SKIES ALLOW H925 TEMPS OF
8-10C TO MIX DOWN TO THE SURFACE...WHICH SHOULD EQUATE TO MID
60S...ESPECIALLY AT THOSE LOCATION WITH NO SNOW PACK.
&&
.AVIATION.../12Z TAF ISSUANCE/
WATCHING TWO UPPER WAVES WITH THE POTENTIAL FOR -SN TODAY...ALONG
WITH THE POTENTIAL FOR SOME RATHER STRONG WINDS THIS EVENING.
FIRST WAVE AND BOUT OF WAA OUT AHEAD OF IT SENDING QUICK BURST OF
IFR VSBY SN ACROSS MN THIS MORNING. IN GENERAL...HAVE SEEN 1-2
HOURS OF AROUND 2SM SNOW IN WRN MN. RUC TAKES THIS SNOW EAST THIS
MORNING...PUTTING STC/MSP/RNH AND POSSIBLE EAU IN LINE FOR
SNOW...THOUGH THE RUC BREAKS THE SNOW DOWN BY THE TIME IT REACHES
EAU. THERE WILL THEN BE ABOUT A 4 HOUR BREAK BEFORE NEXT WAVE
CURRENTLY UP OVER SASK DROPS SE TOWARD NW WI THIS EVENING. BEST
FORCING/MOISTURE LOOKS TO REMAIN NORTH OF THE AREA...THOUGH
REFLECTIVITY FORECASTS AND SREF PROBS DO INDICATE THAT ANOTHER
BRIEF BURST OF SNOW MAY BE POSSIBLE AT AXN/STC/RNH/EAU. MAY ALSO
SEE A BRIEF RETURN TO MVFR CIGS WITH THIS FEATURE AS WELL...BUT
KEPT CONDITIONS VFR GIVEN LOWER CONFIDENCE IN CIGS BEING THAT LOW
THIS FAR SOUTH. FOR WINDS...PRESSURE RISES...COLD AIR ADVECTION
AND MIXING POTENTIAL ALL LINE UP START MOVING INTO THE AXN AREA
AROUND 21Z AND EAU BY 06Z. THIS MEANS BEST GUST POTENTIAL LIKELY
NEAR TO A FEW HOURS AFTER 00Z. BASED ON NAM SOUNDINGS...COLD AIR
ADVECTION LOOKS TO OFFSET LOSS OF MIXING WITH SUNSET...SO WENT
SUBSTANTIALLY HIGHER THAN GFSLAMP WINDS FOR WHEN BEST FORCING FOR
WINDS MOVES THROUGH. WILL SEE A RAPID DECREASE IN NW WINDS AFTER
06Z AS SFC RIDGE MOVES IN FROM THE DAKOTAS.
KMSP...BASED ON FAIRLY WIDESPREAD -SN OBS TO THE WEST...ADDED A
TEMPO GROUP FOR SNOW. RUC/NAM/GFS ALL SPIT OUT A LITTLE SNOW
AROUND 15Z...HENCE THE 14Z TO 16Z TIMING. UPSTREAM OBS HAVE SHOW
VIS DOWN IN THE 1-3SM RANGE WITH CIGS 012-025 IN THE -SN. SKIES
WILL LIKELY BE MAINLY SKC FOR A TIME BEHIND THIS WAVE...BEFORE
THINGS CLOUD BACK UP AHEAD OF THE SASK WAVE. ANY SNOW LOOKS TO
REMAIN NORTH OF THE FIELD...BUT WINDS CERTAINLY LOOK TO BE ROCKING
BETWEEN 00Z AND 06Z AND STRONG COLD AIR ADVECTION ARRIVES. MAY BE
A BIT OVERDONE IN THE TAF...BUT NAM HAS BEEN PRETTY PERSISTENT IN
MIXING DOWN SOME 30 TO 40 KT WINDS IN THIS TIME FRAME...SO ADDED
QUITE A BIT TO THE WINDS. BY FRIDAY MORNING...WINDS WILL LIKELY BE
LGT AND VRB.
//OUTLOOK...FRIDAY THROUGH TUESDAY.
.FRI-SUN...VFR. SAT MORNING...LLWS POSSIBLE WITH STRONG WSW WINDS DURING
THE DAY...POSSIBLE CROSS WIND ISSUES.
.SUN NIGHT-MON...MVFR POSSIBLE WITH CHANCE OF -RA.
.TUE...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM CST THIS EVENING
FOR BENTON-DOUGLAS-KANDIYOHI-MEEKER-MORRISON-POPE-STEARNS-
STEVENS-SWIFT-TODD.
WI...NONE.
&&
$$
JRB/MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
403 AM CST THU MAR 8 2012
.SHORT TERM...THE SHORT TERM FOCUS IS ON WINDS AND SNOW SHOWER
POTENTIAL ACROSS THE NORTHLAND.
AT 330 AM...FAIRLY WIDESPREAD CLOUD COVER WAS MOVING ACROSS THE
NORTHLAND ALTHOUGH THERE WERE SEVERAL AREAS OF THIN CLOUDS.
TEMPERATURES RANGED FROM THE UPPER 20S IN PORTIONS OF NW WI...TO
NEAR 10 ABOVE FAR NORTHWEST.
NORTHWEST FLOW WILL PERSIST ACROSS THE NORTHLAND TODAY. STRONG CAA
WILL BECOME FAIRLY NEUTRAL THROUGHOUT THE DAY. THE NAM INDICATES
THAT AT LEAST A COUPLE SHORTWAVES WILL MOVE THROUGH THE REGION IN
NW FLOW TODAY. EACH WILL BE CAPABLE OF GENERATING SOME SNOW
SHOWERS...BUT THE BEST CHANCE SHOULD BE ACROSS THE NORTH IN THE
AFTERNOON AND EARLY EVENING. WITH COLD AIR ALOFT AND SOME SURFACE
HEATING BETWEEN SNOW SHOWERS...THINK SOME OF THE SNOW SHOWERS
COULD BE FAIRLY STRONG THIS AFTERNOON...EVEN BRINGING SOME GUSTY
WINDS WITH THE SNOW SHOWERS.
THE BIGGER STORY FOR TODAY MAY BE THE STRONG WINDS EXPECTED TO
MOVE INTO THE CWA DURING THE AFTERNOON AND EVENING. HAVE BROUGHT
WINDS UP QUITE A BIT. THE RUC SHOWS STRONG WINDS ALOFT MIXING DOWN
TO THE SURFACE. THE FORECAST SOUNDINGS FOR DULUTH INDICATE 40-50
KNOTS WORKING ITS WAY TO JUST ABOVE THE SURFACE. AS A RESULT...WE
COULD EASILY SEE SOME 20 TO 30 MPH SUSTAINED WINDS THIS AFTERNOON
WITH HIGHER GUSTS AS WELL. WINDS WILL THEN DECREASED OVERNIGHT AS
SKIES CLEAR FROM THE WEST. HAVE DROPPED TEMPS CONSIDERABLY FOR
TONIGHT...CLOSER TO THE MAV GUIDANCE. THIS SHOULD RESULT IN
TEMPERATURES DROPPING BELOW ZERO IN THE NORTH.
FRIDAY SHOULD BE A BIT WARMER...AS WAA PUSHES ACROSS THE REGION.
SHOULD BE SOMEWHAT OF AN INCREASE IN CLOUDS...ESPECIALLY IN THE
NORTH. THINK MOST OF THE PRECIPITATION SHOULD REMAIN IN CANADA.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY. THE EXTENDED
FORECAST PERIOD WILL START OUT DRY AND MILD UNDER WITH A UPPER
RIDGE BUILDING OVER THE WRN GREAT LAKES DUE TO STRONG SWRLY FLOW
IN THE LOW-LEVELS. HOWEVER THE RIDGE WILL GIVE WAY TO A LOW
PRESSURE SYSTEM DEVELOPING OVER THE CNTL PLAINS WHICH IS PROGGED
TO LIFT NEWD OVER THE GREAT LAKES SUNDAY INTO MONDAY. THERE ARE
STILL SOME SIGNIFICANT DIFFERENCES BETWEEN THE VARIOUS NWP MODEL
SOLUTIONS...WITH THE NAM/GFS TAKING THE LOW OFF TO THE SOUTH AND
EAST OF OUR CWA...WHILE THE ECMWF/GEM BRING IT RIGHT OVER THE
NORTHLAND. DUE TO THESE DIFFERENCES...WE WILL KEEP POPS IN THE
CHANCE CATEGORY ATTM. PRECIP TYPE SHOULD BE MAINLY RAIN DUE TO THE
WARM AIRMASS IN PLACE ACROSS THE UPPER MIDWEST. BUT IF THE DYNAMIC
LIFT IS STRONG ENOUGH...THERE COULD BE A WINTRY MIX SUNDAY NIGHT
AND MONDAY MORNING. AFTER THE LOW MOVES OFF TO THE EAST...AN
UNSEASONABLY WARM AND DRY PATTERN WILL DEVELOP ACROSS THE
NORTHLAND NEXT WEEK AS SOUTHWEST FLOW DOMINATES ACROSS THE CTRL
PART OF THE COUNTRY THROUGH WEDNESDAY.
&&
.AVIATION.../06Z TAF ISSUANCE/
MVFR AND ISOLATED IFR IN CLOUDS AND SNOW IN A FRONTAL BAND SHOULD
MOVE OUT OF THE IWD AND GOGEBIC RANGE AREA LATE TONIGHT. MN NORTH
SHORE AND REST OF NORTHWEST WISCONSIN...MVFR IN CLOUDS IMPROVING
TO VFR SCATTERED WITH AREAS OF BROKEN CLOUDS BY DAY BREAK THURSDAY
MORNING. THE REST OF NORTHEAST MN...VFR THROUGH EARLY MORNING.
AREAS OF LOW-END VFR IN CLOUDS WILL DEVELOP MIDMORNING ACROSS
COASTAL WI AND NORTH OF ROUTE 2 IN NORTHEAST MN AFTER MIDMORNING
THURSDAY...AND PERSIST TILL LATE THURSDAY AFTERNOON. VFR CLEAR
BEGINNING THURSDAY EVENING. BRISK NORTHWEST WINDS...GUSTING TO 30
MPH...WILL CONTINUE INTO LATE THURSDAY AFTERNOON...AND SUBSIDE
DURING THURSDAY EVENING.
&&
.POINT TEMPS/POPS...
DLH 32 7 29 25 / 30 30 0 10
INL 28 -5 32 22 / 40 20 10 10
BRD 34 5 35 29 / 30 10 0 0
HYR 35 5 33 27 / 30 30 0 10
ASX 34 10 30 25 / 30 30 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DAP
LONG TERM....BERDES
AVIATION...EOM
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
709 AM CST THU MAR 8 2012
.UPDATE...
ISSUED AT 707 AM CST THU MAR 8 2012
HAVE UPDATE SHORT TERM FORECAST TO REFLECT DRYING TREND OVER THE
NORTHERN PART OF THE CWA. ALSO MENTIONED THE CHANCE FOR SNOW OR
SLEET THIS MORNING IN CENTRAL MISSOURI AS THE CURRENT OB AT KSZL
HAS -PL. OTHERWISE...REST OF FORECAST STILL HOLDS.
BRITT
&&
.SHORT TERM...
ISSUED AT 316 AM CST THU MAR 8 2012
(TODAY AND TONIGHT)
COLD FRONT HAS MOVED ABOUT HALFWAY THROUGH THE CWA AND IS CURRENTLY
ENTERING THE NORTHWESTERN PART OF THE ST. LOUIS METRO AREA. SHOWERS
AND SCATTERED THUNDERSTORMS HAVE DEVELOPED ALONG AND AHEAD OF THE
FRONT IN A BROAD AREA OF 950-850MB MOISTURE CONVERGENCE. THIS
MOISTURE CONVERGENCE IS COINCIDENT WITH LARGE SCALE ASCENT FROM
MID-LEVEL CURRENTLY PASSING THROUGH THE UPPER MIDWEST. A SECOND
LARGER AREA OF PRECIPITATION IS MOVING ACROSS WESTERN MISSOURI WHICH
IS BEING GENERATED BY THE LARGE SCALE ASCENT ON THE TAIL END OF THE
TROUGH AND A LITTLE STRONGER LOW LEVEL CONVERGENCE ON THE NOSE OF A
50KT LOW LEVEL JET OVER THE PLAINS. THIS FORCING WILL CONSOLIDATE
THROUGH THE MORNING PER THE RUC AS THE LOW LEVEL JET VEERS WITH
TIME. THIS SHOULD BE ENOUGH TO KEEP LIKELY OR CATEGORICAL RAIN
CHANCES GOING FOR ABOUT THE SOUTHERN TWO-THIRDS OF THE CWA EARLY
THIS MORNING...WITH A GRADUAL DIMINISHING TREND THROUGH THE DAY AS
THE FORCING PUSHES SOUTH AND EAST. THERE SHOULD BE ENOUGH
INSTABILITY TO KEEP AT LEAST A MENTION OF SCATTERED THUNDERSTORMS
THIS MORNING ALONG AND AHEAD OF THE 850MB COLD FRONT. CAN`T RULE
OUT THE POTENTIAL FOR SOME SNOW OR SLEET ON THE NORTHERN FRINGE OF
THE PRECIPITATION WHERE RUC SOUNDINGS ARE SHOWING THE LOW LEVEL
THERMAL PROFILES COOLING NEAR 0C ABOUT THE TIME THAT THE
PRECIPITATION ENDS. THINK THIS WILL BE A SHORT LIVED EVENT AND
MAINLY FOUND WHERE CONVECTION IS MORE CONCENTRATED. TONIGHT SHOULD
BE DRY AS SUBSIDENCE SETS IN BEHIND THE NORTHERN STREAM TROUGH.
TEMPERATURES SHOULD REMAIN STEADY OR SLOWLY FALL THROUGH THE DAY
OVER THE SOUTHERN HALF OF THE CWA EXTENSIVE CLOUD COVER AND DECENT
COLD AIR ADVECTION BEHIND THE FRONT. GFS MOS TEMPERATURES LOOK A
BIT TOO WARM TONIGHT GIVEN THE MAINLY CLEAR SKIES AND WINDS
TURNING LIGHT AS THE SURFACE RIDGE SETTLES INTO THE AREA.
BRITT
&&
.LONG TERM...
ISSUED AT 330 AM CST THU MAR 8 2012
(FRIDAY THROUGH NEXT WEDNESDAY)
SFC HIGH BUILDS IN BEHIND THE DEPARTING CDFNT ON FRI WITH DRY WX
EXPECTED ON FRI AND MOST OF SAT BEFORE ANOTHER ROUND OF PCPN DVLPS
ON SAT NIGHT AS AN UPPER LOW OVER AZ/NM BEGINS LIFTING NEWD THROUGH
THE CENTRAL CONUS. MODELS CONTINUE TO STRUGGLE WITH HOW AND WHEN
THIS LOW LIFTS NEWD. THE PREVIOUS FOUR RUNS OF THE ECMWF WERE
EVENLY SPLIT BETWEEN KEEPING THE VORT CENTER INTACT /00Z RUNS ON
MARCH 7TH AND 8TH/ AND SPLITTING IT INTO TWO VORT MAXES /12Z RUNS ON
MARCH 6TH AND 7TH...SIMILAR TO WHAT THE GFS HAS BEEN DEPICTING FOR
THE LAST SEVERAL DAYS/. 08/00Z GEM REMAINS SIMILAR TO THE 07/00Z
RUN AND SHOWS THE LOW RETROGRADING TO BAJA CA THEN MOVING THROUGH
MEXICO BEFORE LIFTING THROUGH TX AND INTO NWRN MO. THESE LARGE
DIFFERENCES BETWEEN THE 3 MODELS APPEAR TO STEM FROM DIFFERENT
HANDLING OF THE INTERACTION BETWEEN THE CLOSED LOW AND A SUBTLE
AREA OF ENHANCED VORTICITY THAT SHOULD BE MOVING THROUGH ID/NV AT
08/12Z. DESPITE THE DIFFERENT DETAILS...MODEL SOLUTIONS ALL
SUGGEST ANOTHER ROUND OF PCPN SOMEWHERE BETWEEN SAT NIGHT AND MON
AS THE CLOSED LOW /OR ITS REMNANTS/ FINALLY LIFTS NEWD. WAA SHRA
EXPECTED TO DVLP FIRST FOLLOWED BY AN INCREASE IN PCPN COVERAGE AS
LARGE SCALE LIFT INCREASES WITH THE APPROACHING VORT MAX. MODELS
ARE OFTEN TOO QUICK TO BRING A CLOSED LOW BACK INTO THE PREVAILING
FLOW THEREFORE I WOULD NOT BE SURPRISED IF THIS OVERALL FCST
SCENARIO ENDS UP BEING DELAYED BY A DAY OR SO AS THE MODELS CATCH
UP TO THE ATMOSPHERE.
KANOFSKY
&&
.AVIATION...
ISSUED AT 550 AM CST THU MAR 8 2012
AREA OF RAIN WITH MAINLY MVFR CIGS/VSBYS WILL AFFECT THE TAF SITES
THIS MORNING...THOUGH IT WILL DIMINISH FROM NORTHWEST TO SOUTHEAST
WITH TIME. LIGHTNING HAS DIMINISHED IN THE PAST HOUR WITH THIS
AREA OF PRECIPITATION...SO HAVE NO MORE THAN A CB TO REFLECT THIS
TREND. THERE WAS SOME REPORTS EARLIER OF SNOW AND SLEET OVER
WESTERN MO...BUT THINK PRECIPITATION WILL BE ENDING ABOUT THE SAME
TIME THAT IT WILL BE GETTING COLD ENOUGH FOR THE CHANGEOVER SO
WILL HOLD OFF ON ANY MENTION IN THE UIN TAF FOR NOW. PRECIPITATION
HAS BEEN INCREASING IN AREAL COVERAGE OVER ERN KANSAS...BUT THINK
THIS MAY BE A TEMPORARY TREND...SO WILL HOLD ON TO PRECIPITATION
AT COU AND STL METRO AREA TAF SITES UNTIL 14-16Z. THEREAFTER...
EXPECT DRY CONDITIONS WITH IMPROVING CIGS AND NORTHWESTERLY WINDS
BRING DRIER AIR INTO THE LOW LEVELS.
SPECIFICS FOR KSTL...PRECIPITATION ACROSS MO AND ERN KANSAS IS
MOVING RAPIDLY EASTWARD AND CURRENTLY THINK IT WILL END BY MID
MORNING AT THE TERMINAL. UNTIL THEN...THINK THAT CIGS WILL VARY
FROM HIGH IFR TO MVFR. BY LATE MORNING...NORTHWESTERLY WINDS
WILL BRING DRIER AIR INTO THE LOW LEVELS WHICH SHOULD ALLOW FOR VFR
FLIGHT CONDITIONS.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
551 AM CST THU MAR 8 2012
.SHORT TERM...
ISSUED AT 316 AM CST THU MAR 8 2012
(TODAY AND TONIGHT)
COLD FRONT HAS MOVED ABOUT HALFWAY THROUGH THE CWA AND IS CURRENTLY
ENTERING THE NORTHWESTERN PART OF THE ST. LOUIS METRO AREA. SHOWERS
AND SCATTERED THUNDERSTORMS HAVE DEVELOPED ALONG AND AHEAD OF THE
FRONT IN A BROAD AREA OF 950-850MB MOISTURE CONVERGENCE. THIS
MOISTURE CONVERGENCE IS COINCIDENT WITH LARGE SCALE ASCENT FROM
MID-LEVEL CURRENTLY PASSING THROUGH THE UPPER MIDWEST. A SECOND
LARGER AREA OF PRECIPITATION IS MOVING ACROSS WESTERN MISSOURI WHICH
IS BEING GENERATED BY THE LARGE SCALE ASCENT ON THE TAIL END OF THE
TROUGH AND A LITTLE STRONGER LOW LEVEL CONVERGENCE ON THE NOSE OF A
50KT LOW LEVEL JET OVER THE PLAINS. THIS FORCING WILL CONSOLIDATE
THROUGH THE MORNING PER THE RUC AS THE LOW LEVEL JET VEERS WITH
TIME. THIS SHOULD BE ENOUGH TO KEEP LIKELY OR CATEGORICAL RAIN
CHANCES GOING FOR ABOUT THE SOUTHERN TWO-THIRDS OF THE CWA EARLY
THIS MORNING...WITH A GRADUAL DIMINISHING TREND THROUGH THE DAY AS
THE FORCING PUSHES SOUTH AND EAST. THERE SHOULD BE ENOUGH
INSTABILITY TO KEEP AT LEAST A MENTION OF SCATTERED THUNDERSTORMS
THIS MORNING ALONG AND AHEAD OF THE 850MB COLD FRONT. CAN`T RULE
OUT THE POTENTIAL FOR SOME SNOW OR SLEET ON THE NORTHERN FRINGE OF
THE PRECIPITATION WHERE RUC SOUNDINGS ARE SHOWING THE LOW LEVEL
THERMAL PROFILES COOLING NEAR 0C ABOUT THE TIME THAT THE
PRECIPITATION ENDS. THINK THIS WILL BE A SHORT LIVED EVENT AND
MAINLY FOUND WHERE CONVECTION IS MORE CONCENTRATED. TONIGHT SHOULD
BE DRY AS SUBSIDENCE SETS IN BEHIND THE NORTHERN STREAM TROUGH.
TEMPERATURES SHOULD REMAIN STEADY OR SLOWLY FALL THROUGH THE DAY
OVER THE SOUTHERN HALF OF THE CWA EXTENSIVE CLOUD COVER AND DECENT
COLD AIR ADVECTION BEHIND THE FRONT. GFS MOS TEMPERATURES LOOK A
BIT TOO WARM TONIGHT GIVEN THE MAINLY CLEAR SKIES AND WINDS
TURNING LIGHT AS THE SURFACE RIDGE SETTLES INTO THE AREA.
BRITT
&&
.LONG TERM...
ISSUED AT 330 AM CST THU MAR 8 2012
(FRIDAY THROUGH NEXT WEDNESDAY)
SFC HIGH BUILDS IN BEHIND THE DEPARTING CDFNT ON FRI WITH DRY WX
EXPECTED ON FRI AND MOST OF SAT BEFORE ANOTHER ROUND OF PCPN DVLPS
ON SAT NIGHT AS AN UPPER LOW OVER AZ/NM BEGINS LIFTING NEWD THROUGH
THE CENTRAL CONUS. MODELS CONTINUE TO STRUGGLE WITH HOW AND WHEN
THIS LOW LIFTS NEWD. THE PREVIOUS FOUR RUNS OF THE ECMWF WERE
EVENLY SPLIT BETWEEN KEEPING THE VORT CENTER INTACT /00Z RUNS ON
MARCH 7TH AND 8TH/ AND SPLITTING IT INTO TWO VORT MAXES /12Z RUNS ON
MARCH 6TH AND 7TH...SIMILAR TO WHAT THE GFS HAS BEEN DEPICTING FOR
THE LAST SEVERAL DAYS/. 08/00Z GEM REMAINS SIMILAR TO THE 07/00Z
RUN AND SHOWS THE LOW RETROGRADING TO BAJA CA THEN MOVING THROUGH
MEXICO BEFORE LIFTING THROUGH TX AND INTO NWRN MO. THESE LARGE
DIFFERENCES BETWEEN THE 3 MODELS APPEAR TO STEM FROM DIFFERENT
HANDLING OF THE INTERACTION BETWEEN THE CLOSED LOW AND A SUBTLE
AREA OF ENHANCED VORTICITY THAT SHOULD BE MOVING THROUGH ID/NV AT
08/12Z. DESPITE THE DIFFERENT DETAILS...MODEL SOLUTIONS ALL
SUGGEST ANOTHER ROUND OF PCPN SOMEWHERE BETWEEN SAT NIGHT AND MON
AS THE CLOSED LOW /OR ITS REMNANTS/ FINALLY LIFTS NEWD. WAA SHRA
EXPECTED TO DVLP FIRST FOLLOWED BY AN INCREASE IN PCPN COVERAGE AS
LARGE SCALE LIFT INCREASES WITH THE APPROACHING VORT MAX. MODELS
ARE OFTEN TOO QUICK TO BRING A CLOSED LOW BACK INTO THE PREVAILING
FLOW THEREFORE I WOULD NOT BE SURPRISED IF THIS OVERALL FCST
SCENARIO ENDS UP BEING DELAYED BY A DAY OR SO AS THE MODELS CATCH
UP TO THE ATMOSPHERE.
KANOFSKY
&&
.AVIATION...
ISSUED AT 550 AM CST THU MAR 8 2012
AREA OF RAIN WITH MAINLY MVFR CIGS/VSBYS WILL AFFECT THE TAF SITES
THIS MORNING...THOUGH IT WILL DIMINISH FROM NORTHWEST TO SOUTHEAST
WITH TIME. LIGHTNING HAS DIMINISHED IN THE PAST HOUR WITH THIS
AREA OF PRECIPITATION...SO HAVE NO MORE THAN A CB TO REFLECT THIS
TREND. THERE WAS SOME REPORTS EARLIER OF SNOW AND SLEET OVER
WESTERN MO...BUT THINK PRECIPITATION WILL BE ENDING ABOUT THE SAME
TIME THAT IT WILL BE GETTING COLD ENOUGH FOR THE CHANGEOVER SO
WILL HOLD OFF ON ANY MENTION IN THE UIN TAF FOR NOW. PRECIPITATION
HAS BEEN INCREASING IN AREAL COVERAGE OVER ERN KANSAS...BUT THINK
THIS MAY BE A TEMPORARY TREND...SO WILL HOLD ON TO PRECIPITATION
AT COU AND STL METRO AREA TAF SITES UNTIL 14-16Z. THEREAFTER...
EXPECT DRY CONDITIONS WITH IMPROVING CIGS AND NORTHWESTERLY WINDS
BRING DRIER AIR INTO THE LOW LEVELS.
SPECIFICS FOR KSTL...PRECIPITATION ACROSS MO AND ERN KANSAS IS
MOVING RAPIDLY EASTWARD AND CURRENTLY THINK IT WILL END BY MID
MORNING AT THE TERMINAL. UNTIL THEN...THINK THAT CIGS WILL VARY
FROM HIGH IFR TO MVFR. BY LATE MORNING...NORTHWESTERLY WINDS
WILL BRING DRIER AIR INTO THE LOW LEVELS WHICH SHOULD ALLOW FOR VFR
FLIGHT CONDITIONS.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
402 AM CST THU MAR 8 2012
.DISCUSSION...
THE MAIN CHALLENGES WILL BE WIND AND BLOWING SNOW POTENTIAL TODAY
AND TEMPS THROUGHOUT. MODELS ARE NOT HANDLING THIS INITIAL SNOW
BAND OVER THE REGION WELL AT ALL...WITH THE RUC DOING THE BEST IN
THE NEAR TERM. SOME REPORTS AND RADAR INDICATING A NARROW BAND OF
1-2 INCHES FROM GRAFTON TO MINTO TO MANVEL INTO THE GRAND FORKS
AREA. WILL USE A MODEL BLEND AND NOT WARM THINGS UP TOO QUICKLY
WITH STILL A DECENT SNOW PACK OVER THE REGION.
FOR TODAY...SEVERAL SHORTWAVES WILL ROTATE THROUGH THE REGION. A
COLD FRONT WILL PASS THROUGH THE AREA THIS AFTERNOON...ALONG WITH
ABOUT 40-50KT TO MIX THROUGHOUT THE ENTIRE FORECAST AREA. A STRONG
PRESSURE RISE WILL ALSO COME DOWN THE VALLEY...SO EXPECT WINDY
CONDITIONS THIS AFTERNOON WITH GUSTS TO 40 MPH LIKELY. WILL ISSUE
A WINTER WEATHER ADVISORY FOR THE NORTHERN VALLEY WITH SOME SNOW
THIS MORNING...AND SNOW SHOWERS WITH THE FRONT SO THERE IS FRESH
SNOW TO BLOW AROUND. THE STRONG WINDS SHOULD CAUSE BLOWING SNOW
AND OPEN COUNTRY VSBY ISSUES...ESPECIALLY WHEN SNOW SHOWERS
COMBINE WITH INCREASING WINDS THIS AFTERNOON. WILL GO WITH A WIND
ADVISORY FOR THE REST OF THE REGION FROM 18Z-00Z. TEMPS WON/T WARM
TOO MUCH GIVEN COLD FRONT AND INCREASING CLOUDS AND ISOLATED SNOW
SHOWERS.
FOR TONIGHT...SFC HIGH SETTLES OVER THE REGION AND IT WILL GET
COLD IN THE EAST...WHERE TEMPS SHOULD DIP BELOW ZERO. EXPECT
WARMER TEMPS TO THE WEST WITH RETURN FLOW BEGINNING AFTER 06Z.
ON FRI...SOUTHERLY WINDS WILL INCREASE...ALTHOUGH WITH A COLD
START TEMPS WON/T GET TOO WARM IN THE VALLEY. HAVE LOWERED TEMPS
SOME FROM PREVIOUS FORECAST ALTHOUGH WITH SUNSHINE EXPECT AT LEAST
SOME MELTING.
ON SAT/SUN...MORE OF A WESTERLY SFC FLOW AND WARMING THERMAL
FIELDS AT ALL LEVELS WILL MEAN TEMPS WELL ABOVE NORMAL. EXPECT THE
WARMEST READINGS IN THE WEST AND TREED AREAS IN THE EAST...WITH
COLDER READINGS ON THE VALLEY FLOOR.
ON MON...ANY PRECIP SHOULD REMAIN SOUTH OF THE AREA AND WILL KEEP
IT DRY WITH WARM WEATHER CONTINUING NEXT WEEK.
&&
.AVIATION...
MVFR/IFR CONDITIONS EXPECTED WITH CURRENT SNOW BAND AS IT PUSHES
EAST EARLY THIS MORNING. NW WINDS WILL INCREASE IN ALL AREAS THIS
AFTERNOON AND GUSTS TO 35KT WILL BE POSSIBLE. THERE COULD BE SOME
BLSN IN THE NORTH THIS AFTERNOON...AND VSBYS SHOULD BE REDUCED ALONG
WITH SOME SNOW SHOWERS THIS AFTERNOON WITH COLD FRONT. WINDS
SHOULD QUICKLY SUBSIDE AFTER SUNSET.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
NDZ028>030-038-039-049-052-053.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING
FOR NDZ006>008-014>016-024-026-027-054.
MN...WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
MNZ002-003-006-009-016-017-022>024-027>032-040.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING
FOR MNZ001-004-005-007-008-013>015.
&&
$$
DK
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1042 AM MST THU MAR 8 2012
.SHORT TERM...
.AVIATION...SHOULD SEE VFR CONDITIONS AND GENERALLY LIGHT WINDS
FOR THE NEXT 24 H. SHSN WILL BE CONFINED TO SE CO S OF HGWY 160.
BKN COGS AT KPUB SHOULD DISSIPATE BY EARLY AFTERNOON. ROSE
&&
.PREV DISCUSSION... /ISSUED 905 AM MST THU MAR 8 2012/
UPDATE...
HAVE UPDATED THE FORECAST TO CUT BACK POPS OVER THE CWA AND TO
CANCEL THE WINTER HEADLINES. COULD STILL SEE SOME LIGHT SNOW
ACCUMS OVR THE SRN MTS AND ADJACENT PLAINS...BUT IMPACT SHOULD BE
MINIMAL AT THIS POINT. 44
PREV DISCUSSION... /ISSUED 718 AM MST THU MAR 8 2012/
UPDATE...
LAST SEVERAL RUNS OF THE HRRR MODEL CONTINUE TO INDICATE THAT THE
SNOW OVER THE SOUTHERN MOUNTAINS WILL END LATER THIS MORNING AS
DRIER AIR ADVECTS INTO THE REGION. FOR THIS REASON WILL LET THE
WINTER STORM HILITES END LATER THIS MORNING.
PREV DISCUSSION... /ISSUED 414 AM MST THU MAR 8 2012/
SHORT TERM...
(TODAY AND TONIGHT)
SNOW FINALLY MATERIALIZING ACROSS THE SANGRES/WETS AND
SURROUNDING AREAS...
CURRENTLY...
DURING THE LAST FEW HOURS...RADAR RETURNS HAVE INCREASED
SIGNIFICANTLY OVER THE SOUTHERN MTNS AND ADJACENT PLAINS.
SNOW...LIKELY HEAVY...WAS INDICATED ON THE EAST SLOPES OF THE WETS
AND IN THE VICINITY OF THE SPANISH PEAKS. COMPOSITE RADAR IS
CLEARLY INDICATING THE CIRCULATION ASSOCIATED WITH THE WELL
DEFINED...ALBEIT COMPACT...UPPER LOW...WHICH WAS LOCATED NEAR THE 4
CORNERS. THE SNOW HAS EXTENDED AS FAR NORTH AND EAST AS
PUEBLO...WHERE A TRACE OF SNOW HAS OCCURRED DURING THE LAST HOUR OR
SO.
TODAY...
MAIN CHANGE TO THE FCST WAS TO EXTEND THE WINTER STORM WARNING UNTIL
6 PM FOR A SMALL PART OF THE REGION. THIS REGION ENCOMPASSES THE
SOUTHERN SANGRE DE CRISTO MOUNTAINS. FOR ALL OTHER AREAS...THE
WINTER STORM WARNING WILL EXPIRE AT NOON.
ALL MODELS CONTINUE TO INDICATE THE HEAVIEST SNOW WILL OCCUR WHERE
IT IS OCCURRING NOW...THAT IS...ALONG THE EAST SLOPES OF THE S MTNS
AND ADJACENT I-25 CORRIDOR. SNOW IS LIKELY OCCURRING ALONG THE E SLOPES
OF THE SAN JUANS BASED ON SAT PIX IMGY AND MEAGER RADAR RETURNS AS
SEEN BY NWS RADARS.
UPPER LOW...WHICH IS LACKING SIGNIFICANTLY IN MOISTURE...IS FCST TO
TRACK E-SE TODAY ACROSS NM. THIS WILL KEEP THE REGION IN DEEP
UPSLOPE FLOW. BEST FORCING WILL BE OVER THE S TIER WHERE I HAVE KEPT
THE POPS THE HIGHEST.
TONIGHT...
ALTHOUGH THE LOW IS FCST TO TRACK BACK NWD AND ACTUALLY RETROGRADE
WWD ACROSS FAR N NM TONIGHT INTO TOMORROW...ALL GUIDANCE IS SHOWING
VERY LITTLE...IF ANY...QPF OVER THE REGION. THE ONLY QPF BEING
PRINTED OUT IS ACROSS THE FAR S TIER...ALONG THE IMMEDIATE CO/NM
BORDER. ALTHOUGH UPSLOPE FLOW IS RATHER STRONG AND DEEP...THIS
SYSTEM IS LACKING (DRAMATICALLY) WRT MOISTURE. SOUNDINGS ACROSS THE
PLAINS SHOW VERY DRY AIR THROUGHOUT THE COLUMN ADVECTING INTO THIS
SYSTEM FROM THE CENTRAL HIGH PLAINS. LIKEWISE...MOST AREAS TONIGHT
WILL SEE MOSTLY CLEAR SKIES...WITH THE EXCEPTION BEING ALONG THE
CO/NM BORDER. /34
LONG TERM...
(FRIDAY THROUGH WEDNESDAY)
FRIDAY AND SATURDAY...THE LOW PRESSURE SYSTEM IS EXPECTED TO SIT IN
THE VICINITY OF THE OK AND TX PANHANDLES ON FRI...BUT HOW IT MOVES
FROM THERE IS REALLY IN QUESTION NOW. MULTIPLE MODELS AND MODEL RUNS
ARE SHOWING DIFFERING SOLUTIONS ON WHERE THE LOW CENTER WILL
TRACK...FROM RETROGRADING BACK TO THE WEST ACROSS NM...TO EJECTING
NORTH...TO SITTING IN PLACE. THE ONE THING MODELS SEEMED TO AGREE
UPON WAS THAT THERE IS NOT A LOT OF MOISTURE ASSOCIATED WITH THIS
SYSTEM...SO WILL FORECAST MEAGER QPF. GIVEN THE UNCERTAINTY OF THE
TRACK...KEPT THE BEST PCPN CHANCES ALONG THE SOUTHERN PORTIONS OF
THE CWA WITH FLOW BANKING UP AGAINST THE SOUTHERN FOOTHILLS AND S
SANGRES. ON SAT...MODELS INDICATE THAT THE LOW WILL FINALLY MAKE
SOME SORT OF MOVE OUT OF THE AREA...AND TAPERED POPS OFF THROUGH
THE DAY. TEMPS BOTH DAYS SHOULD WARM INTO THE 40S AND 50S...WITH
THE COLDEST TEMPS ALONG THE SOUTHERN TIER.
SUNDAY THROUGH WEDNESDAY...THE UPPER LOW EXITS THE REGION...SETTING
UP WEST TO SOUTHWEST FLOW ACROSS THE 4 CORNERS AND ROCKIES INTO THE
NEXT WORK WEEK FOR DRY CONDITIONS AND WARMING TEMPS. 27
AVIATION...
FOR KCOS...MVFR CONDITIONS WILL CONTINUE UNTIL ABOUT 14Z AND THEN
DRIER AIR SHOULD ADVECT IN DECREASING THE CLOUDS. VFR SHOULD LAST
THROUGH THE REST OF THE PERIOD.
FOR KPUB...SAME AS KCOS ALTHOUGH LOWER CIGS/LIGHT SNOW SHOULD LAST
UNTIL ABOUT 16Z.
FOR KALS...OCCNL MVFR CONDITIONS WILL BE POSSIBLE THROUGH ABOUT
15Z...AND THEN MVFR IS EXPECTED THE REST OF THE FCST PERIOD.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
44/31
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1020 AM MST THU MAR 8 2012
.UPDATE...
ISSUED AT 1020 AM MST THU MAR 8 2012
CUT-OFF UPPER LOW OVER SOUTHWEST NM WAS KEEPING E-NE FLOW ACROSS
THE FORECAST AREA TODAY...WITH CLOUDS PERSISTING OVER A PORTION OF
SW CO WHERE ISOLATED TO SCATTERED LIGHT SNOW SHOWERS ARE STILL
POSSIBLE FROM DAYTIME HEATINGJ PRODUCING SHALLOW AFTERNOON
INSTABILITY. SURFACE HIGH PRESSURE WAS BUILDING INTO NE UT/NW CO.
EARLY LOOK AT THE NEW MODELS RUNS SHOWS THE CUT- OFF LOW SHIFTING
TOWARDS EASTERN OR NORTHEASTERN NM TONIGHT AND FRIDAY AS A SHORTWAVE
CURRENTLY ENTERING NORTHERN NV DROPS SOUTHWARD. THE CURRENT
FORECAST LOOKS ON TRACK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 200 AM MST THU MAR 8 2012
THE UPPER LEVEL LOW WAS SAGGING SOUTH ALONG THE AZ-NM BORDER THIS
MORNING THEN WILL EJECT SLOWLY EAST ACROSS SOUTHERN NM THIS
AFTERNOON. ASSOCIATED DYNAMICAL LIFT IS SOUTH OF THE CWA AND WRAP-
AROUND MOISTURE IS LIMITED. THIS WOULD PRODUCE SOME LIGHT
ACCUMULATION IN THE VICINITY OF MONARCH...SLUMGULLION...AND WOLF
CREEK PASSES TODAY. THE HRRR AND NAM12 ALSO PRODUCE LIGHT
ACCUMULATION OVER THE MANCOS RIDGE THROUGH THIS AFTERNOON.
OTHERWISE MOSTLY SUNNY SKIES WILL PREVAIL.
AT THE SURFACE LOW PRESSURE NEAR THE FOUR CORNERS AND COLD HIGH
PRESSURE PUSHING DOWN THE FRONT RANGE IS PRODUCING NE GRADIENT
WINDS. MTN TOP NE WINDS ARE GUSTING 20-30 OVER EXPOSED TERRAIN.
THE GRADIENT RELAXES THROUGH THE AFTERNOON.
TONIGHT THE UPPER LOW SETTLES ONTO THE EASTERN NM PLAINS WHERE IT
WILL LANGUISH INTO THE WEEKEND. THIS KEEPS THE FORECAST AREA IN A
LIGHT EAST FLOW ALOFT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 311 AM MST THU MAR 8 2012
THE MIDRANGE MODELS SEEM TO BE STALLING THE CLOSED LOW OVER NEW
MEXICO FRIDAY AND FRIDAY NIGHT. THE GFS KEEPS THE 500 MB CENTER
OVER NE NM AND THE PANHANDLES OF TX AND OK FRI. THEN LIFTS IT NORTH
INTO EXTREME SE CO SAT...AND TAKES THE LOW CENTER TO WESTERN KS
SUN MORNING. THE ECMWF RETROGRADES THE LOW CENTER BACK TO WESTERN
NM FRI THEN PUSHES IT EAST SAT AND INTO THE TX PANHANDLE ABOUT 18Z
SUN. THE GFS SOLUTION SHOULD RESULT IN NEARLY CLOUDLESS SKIES
NORTH OF THE SAN JUAN MOUNTAINS FRI THROUGH THE WEEKEND. THE ECMWF
WITH ITS LOW CENTER FURTHER WEST MAY KEEP MORE CLOUD COVER OVER
THE SOUTHERN HALF OF THE FORECAST AREA FRI AND SAT. BOTH SCENARIOS
PROVIDE LITTLE CHANCE OF PRECIP OUTSIDE OF ISOLD SHOWERS IN THE SAN
JUANS THROUGH THE WEEKEND.
SUNDAY IN BOTH MODELS SHOULD BRING CONTINUED WARM ADVECTION AS
THE FLOW ALOFT BECOMES SOUTHWESTERLY. MAX TEMPS SUN THROUGH WED
SHOULD BE 5-10 DEGREES ABOVE NORMAL ACROSS THE FORECAST AREA.
EXPECT LITTLE CLOUD COVER AND DRY CONDITIONS AS WELL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1020 AM MST THU MAR 8 2012
VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH 18Z FRI WITH NORTHEAST
FLOW ALOFT.
CLOUDS LINGERED OVER PORTIONS OF SW CO FROM KMYP TO KDRO LATE THIS
MORNING. SOME LOW-TOPPED CONVECTION COULD PRODUCE ISOLD TO SCT LIGHT
SNOW SHOWERS OVER THE SAN JUAN MOUNTAINS FROM AFTERNOON INSTABILITY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JAD
SHORT TERM...JOE
LONG TERM....CC
AVIATION...JAD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
905 AM MST THU MAR 8 2012
.UPDATE...
HAVE UPDATED THE FORECAST TO CUT BACK POPS OVER THE CWA AND TO
CANCEL THE WINTER HEADLINES. COULD STILL SEE SOME LIGHT SNOW
ACCUMS OVR THE SRN MTS AND ADJACENT PLAINS...BUT IMPACT SHOULD BE
MINIMAL AT THIS POINT. ROSE
&&
.PREV DISCUSSION... /ISSUED 718 AM MST THU MAR 8 2012/
UPDATE...
LAST SEVERAL RUNS OF THE HRRR MODEL CONTINUE TO INDICATE THAT THE
SNOW OVER THE SOUTHERN MOUNTAINS WILL END LATER THIS MORNING AS
DRIER AIR ADVECTS INTO THE REGION. FOR THIS REASON WILL LET THE
WINTER STORM HILITES END LATER THIS MORNING.
PREV DISCUSSION... /ISSUED 414 AM MST THU MAR 8 2012/
SHORT TERM...
(TODAY AND TONIGHT)
.SNOW FINALLY MATERIALIZING ACROSS THE SANGRES/WETS AND
SURROUNDING AREAS...
CURRENTLY...
DURING THE LAST FEW HOURS...RADAR RETURNS HAVE INCREASED
SIGNIFICANTLY OVER THE SOUTHERN MTNS AND ADJACENT PLAINS.
SNOW...LIKELY HEAVY...WAS INDICATED ON THE EAST SLOPES OF THE WETS
AND IN THE VICINITY OF THE SPANISH PEAKS. COMPOSITE RADAR IS
CLEARLY INDICATING THE CIRCULATION ASSOCIATED WITH THE WELL
DEFINED...ALBEIT COMPACT...UPPER LOW...WHICH WAS LOCATED NEAR THE 4
CORNERS. THE SNOW HAS EXTENDED AS FAR NORTH AND EAST AS
PUEBLO...WHERE A TRACE OF SNOW HAS OCCURRED DURING THE LAST HOUR OR
SO.
TODAY...
MAIN CHANGE TO THE FCST WAS TO EXTEND THE WINTER STORM WARNING UNTIL
6 PM FOR A SMALL PART OF THE REGION. THIS REGION ENCOMPASSES THE
SOUTHERN SANGRE DE CRISTO MOUNTAINS. FOR ALL OTHER AREAS...THE
WINTER STORM WARNING WILL EXPIRE AT NOON.
ALL MODELS CONTINUE TO INDICATE THE HEAVIEST SNOW WILL OCCUR WHERE
IT IS OCCURRING NOW...THAT IS...ALONG THE EAST SLOPES OF THE S MTNS
AND ADJACENT I-25 CORRIDOR. SNOW IS LIKELY OCCURRING ALONG THE E SLOPES
OF THE SAN JUANS BASED ON SAT PIX IMGY AND MEAGER RADAR RETURNS AS
SEEN BY NWS RADARS.
UPPER LOW...WHICH IS LACKING SIGNIFICANTLY IN MOISTURE...IS FCST TO
TRACK E-SE TODAY ACROSS NM. THIS WILL KEEP THE REGION IN DEEP
UPSLOPE FLOW. BEST FORCING WILL BE OVER THE S TIER WHERE I HAVE KEPT
THE POPS THE HIGHEST.
TONIGHT...
ALTHOUGH THE LOW IS FCST TO TRACK BACK NWD AND ACTUALLY RETROGRADE
WWD ACROSS FAR N NM TONIGHT INTO TOMORROW...ALL GUIDANCE IS SHOWING
VERY LITTLE...IF ANY...QPF OVER THE REGION. THE ONLY QPF BEING
PRINTED OUT IS ACROSS THE FAR S TIER...ALONG THE IMMEDIATE CO/NM
BORDER. ALTHOUGH UPSLOPE FLOW IS RATHER STRONG AND DEEP...THIS
SYSTEM IS LACKING (DRAMATICALLY) WRT MOISTURE. SOUNDINGS ACROSS THE
PLAINS SHOW VERY DRY AIR THROUGHOUT THE COLUMN ADVECTING INTO THIS
SYSTEM FROM THE CENTRAL HIGH PLAINS. LIKEWISE...MOST AREAS TONIGHT
WILL SEE MOSTLY CLEAR SKIES...WITH THE EXCEPTION BEING ALONG THE
CO/NM BORDER. /34
LONG TERM...
(FRIDAY THROUGH WEDNESDAY)
FRIDAY AND SATURDAY...THE LOW PRESSURE SYSTEM IS EXPECTED TO SIT IN
THE VICINITY OF THE OK AND TX PANHANDLES ON FRI...BUT HOW IT MOVES
FROM THERE IS REALLY IN QUESTION NOW. MULTIPLE MODELS AND MODEL RUNS
ARE SHOWING DIFFERING SOLUTIONS ON WHERE THE LOW CENTER WILL
TRACK...FROM RETROGRADING BACK TO THE WEST ACROSS NM...TO EJECTING
NORTH...TO SITTING IN PLACE. THE ONE THING MODELS SEEMED TO AGREE
UPON WAS THAT THERE IS NOT A LOT OF MOISTURE ASSOCIATED WITH THIS
SYSTEM...SO WILL FORECAST MEAGER QPF. GIVEN THE UNCERTAINTY OF THE
TRACK...KEPT THE BEST PCPN CHANCES ALONG THE SOUTHERN PORTIONS OF
THE CWA WITH FLOW BANKING UP AGAINST THE SOUTHERN FOOTHILLS AND S
SANGRES. ON SAT...MODELS INDICATE THAT THE LOW WILL FINALLY MAKE
SOME SORT OF MOVE OUT OF THE AREA...AND TAPERED POPS OFF THROUGH
THE DAY. TEMPS BOTH DAYS SHOULD WARM INTO THE 40S AND 50S...WITH
THE COLDEST TEMPS ALONG THE SOUTHERN TIER.
SUNDAY THROUGH WEDNESDAY...THE UPPER LOW EXITS THE REGION...SETTING
UP WEST TO SOUTHWEST FLOW ACROSS THE 4 CORNERS AND ROCKIES INTO THE
NEXT WORK WEEK FOR DRY CONDITIONS AND WARMING TEMPS. 27
AVIATION...
FOR KCOS...MVFR CONDITIONS WILL CONTINUE UNTIL ABOUT 14Z AND THEN
DRIER AIR SHOULD ADVECT IN DECREASING THE CLOUDS. VFR SHOULD LAST
THROUGH THE REST OF THE PERIOD.
FOR KPUB...SAME AS KCOS ALTHOUGH LOWER CIGS/LIGHT SNOW SHOULD LAST
UNTIL ABOUT 16Z.
FOR KALS...OCCNL MVFR CONDITIONS WILL BE POSSIBLE THROUGH ABOUT
15Z...AND THEN MVFR IS EXPECTED THE REST OF THE FCST PERIOD.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
44/31
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
236 PM CST THU MAR 8 2012
.DISCUSSION...
1008 AM CST
NO REAL ISSUES LATE THIS MORNING OR GOING INTO THE
AFTERNOON...WITH MINOR CHANGES TO POP/WX GRIDS AS RAIN HAS EXITED
THE CWA...AND SOME ADJUSTMENTS TO CLOUD TRENDS TODAY.
SURFACE TROUGH AND ASSOCIATED COLD FRONT HAVE SINCE SHIFTED
EAST/SOUTHEAST OF THE CWA THIS MORNING...AS HIGHER PRESSURE BUILDS
EAST WITH PRESSURE RISES NOTED ACROSS MUCH OF THE REGION THIS
HOUR. ALTHOUGH...MAIN RIDGE AXIS REMAINS TO THE WEST OVER THE
CENTRAL PLAINS AND APPEARS AS IF IT WILL REMAIN SITUATED TO THE
WEST WITH A FAIRLY TIGHT PRESSURE GRADIENT TO REMAIN OVER THE CWA
TODAY. THIS WILL OCCUR AS AN UPPER LEVEL TROUGH REMAINS
OVERHEAD...WITH A MID LEVEL SHORT WAVE TROUGH DROPPING SOUTHEAST
THROUGH THE UPPER MIDWEST...WHICH WILL PLAY A FACTOR WITH CLOUD
TRENDS TODAY. LOW LEVEL CLOUD COVER WILL CONTINUE TO SHIFT EAST
THROUGH THE SOUTHEAST PORTION OF THE CWA THROUGH MID DAY WITH A
PARTIAL CLEARING TREND EXPECTED THROUGH MID DAY. ALTHOUGH...WITH
COOLER AIR MOVING THROUGH...STEEPENING LOW LEVEL LAPSE RATES...AND
THE APPROACHING WAVE...A REDEVELOPMENT OF CU/STRATO CU WILL HELP
TO PROVIDE WHATEVER CLEAR SKIES ARE IN PLACE TO BECOME MORE PARTLY
SUNNY/CLOUDY THIS AFTERNOON. THIS DIURNAL CU WILL THEN DIMINISH
WITH A CLEARING TREND EXPECTED ONCE AGAIN LATE THIS AFTERNOON AND
EARLY EVENING.
EVENING SKIES GRIDS MAY NEED TO BE ADJUSTED FOR THE AFTERNOON
ISSUANCE...AS A QUICKLY APPROACHING COLD FRONTAL BOUNDARY MAY
PROVIDE ADDITIONAL CLOUD COVER LATE THIS EVENING BEFORE HIGH
PRESSURE MOVES OVERHEAD EARLY FRIDAY.
RODRIGUEZ
//PREV DISCUSSION...
307 AM CST
THE IMMEDIATE CONCERNS WITH THE FORECAST ARE WITH THE FALLING
TEMPERATURES...AS WELL AS CONTINUED POST FRONTAL SHOWERS AND EVEN
SOME THUNDER CHANCES THIS MORNING ACROSS THE SOUTHERN HALF OF THE
AREA. THEN ATTENTION TURNS TO RAIN POTENTIAL SUNDAY...FOLLOWED BY
THE TEMPERATURES NEXT WEEK AS A SIGNIFICANT WARM UP...OR RE-WARM UP
WE SHOULD SAY...LOOKS LIKELY.
FOR THE CURRENT SITUATION...A VERY WELL-DEFINED COLD FRONT IS
CLEARING THE FORECAST AREA EARLY THIS MORNING. ROBUSTLY WARM AIR
AHEAD OF THIS FEATURE HELPED CHICAGO BREAK THEIR RECORD WARM LOW
FOR YESTERDAY /54 DEGREES/. THE COMBINATION OF THE FRONTAL PASSAGE
AND RAIN TOOK TEMPERATURES DOWN AS MUCH AS 14 DEGREES IN ONE
HOUR AT SOME LOCATIONS. A GOOD PART OF THE SHOWER ACTIVITY IS
POST-FRONTAL...ASSOCIATED WITH ELEVATED MOISTURE TRANSPORT AND
STRONG CONVERGENCE ALONG THE BOUNDARY. ITS A GOOD THING A LOT OF
THIS IS POST FRONTAL...AS MORE SHOWER ACTIVITY AHEAD OF THE FRONT
COULD HAVE POTENTIALLY STEERED DOWN SOME OF THE 55 KT FLOW AT 1500
FT SEEN ON THE KLOT DOPPLER VELOCITY FOR HOURS AHEAD OF THE FRONT.
THE NORTHWEST WIND SPEEDS BEHIND THE FRONT ARE ACTUALLY QUITE A
BIT LOWER...GUSTING AT TIMES TO NEAR 25 MPH. THIS SHOULD CONTINUE
TO BE THE CASE INTO THIS AFTERNOON.
AN INTERESTING AREA OF ELEVATED CONVECTION IS SEEN IN NORTHERN MO
AS OF 300 AM HAVING ORIGINATED IN KS WITH A SHORT WAVE PER WATER
VAPOR ANALYSIS. THIS AREA CONTINUES TO GROW UPSCALE EAST
NORTHEAST...WELL BEHIND THE FRONT. RUC AND NAM CROSS SECTIONS
THROUGH THIS AREA SHOW STRONG MID-LEVEL FRONTOGENESIS AND A VERY
DEEP LAYER /AROUND 200 MB/ OF NEGATIVE EPV AND SLIGHTLY
DECREASING THETA-E...INDICATING CONVECTIVE INSTABILITY PRESENT.
THE RUC FORECAST FOR THE FORCING AND INSTABILITY...AND HRRR
PROJECTION OF REFLECTIVITY...SEEMS TO HAVE A STRONG HANDLE ON
THIS...WHILE MOST OTHER GUIDANCE DOES NOT. THIS AREA IS FORECAST
BY THE RUC/HRRR TO COME ACROSS THE SOUTHERN HALF OF THE FORECAST
AREA EARLY THIS MORNING. THE CONVECTIVE SIGNAL WEAKENS
SOMEWHAT...BUT STILL THINK ISOLATED TO SCATTERED THUNDER SHOULD BE
SEEN AT LEAST CLOSE IF NOT INTO THE SOUTHERN FORECAST AREA. THERE
COULD BE SOME SMALL HAIL WITH THIS GIVEN THE LOW WET BULB ZERO
VALUES. THIS SHOULD EXIT BY 10 AM TO NOON...WITH LINGERING CLOUDS
BEHIND THE FRONT ACROSS THE SOUTHERN AREA INTO EARLY TO MID
AFTERNOON.
COLD AIR ADVECTION BEHIND THE FRONT WILL UNDERCUT THE MORNING
CLOUDS AND SHOWERS IN THE SOUTH...HELPING TO KEEP TEMPERATURES
NEARLY STEADY OR EVEN CONTINUING TO FALL THROUGH MID-MORNING.
CLEARING BY LATE MORNING INTO AFTERNOON WILL ALLOW FOR SOME
REBOUND...BUT PROBABLY ONLY INTO THE LOWER TO MID 40S. CONFIDENCE
ON THE DEGREE OF RECOVERY IS SOMEWHAT LOW DUE TO WEIGHING THE COLD
AIR ADVECTION/CLOUD IMPACT THIS MORNING.
THE UPPER TROUGH OVER MN EARLY THIS MORNING WILL PASS OVER THE
GREAT LAKES AND BE RE-ENFORCED BY A STRONG JET MAX TO THE
NORTHWEST. THIS WILL HELP TO PUSH A SECONDARY COLD FRONT SOUTH
THROUGH THE AREA LATE THIS EVENING INTO OVERNIGHT. THIS LOOKS TO
REALLY SEND DEW POINTS DOWN AND POTENTIALLY TEMPERATURES FURTHER
TOO. THE COLD POCKET ASSOCIATED WITH THIS SHOULD DEVELOP SOME
STRATOCU TONIGHT ACROSS NORTHERN AND EASTERN AREAS THAT MAY
POTENTIALLY LINGER INTO FRI MORNING.
HIGH PRESSURE WILL THEN PREVAIL FRIDAY INTO EARLY SATURDAY...WITH
RETURN FLOW THEN SETTING UP FOR SATURDAY...WHICH SHOULD BE A
FAIRLY PLEASANT AND SUNNY DAY. THE WELL-ORGANIZED CLOSED UPPER
LOW OVER THE DESERT SOUTHWEST WILL DRIFT GRADUALLY NORTHEAST ON
SATURDAY...THEN BEGIN TO BECOME MORE NEUTRAL TO NEGATIVELY TILED
AS IT LIFTS OVER OUR AREA ON SUNDAY INTO SUNDAY NIGHT. THE
AMOUNT OF MOISTURE RETURN AHEAD OF THIS IS FAIRLY SHORT IN
DURATION...BUT IT CERTAINLY LOOKS TO BE DEEP ENOUGH AND WITHIN
STRONG ENOUGH ISENTROPIC LIFT FOR FAIRLY WIDESPREAD RAIN/SHOWERS
ON SUNDAY. HAVE CONTINUED TO INCH UP POPS. WHILE THE SYSTEM DRY
SLOT EVOLVES RIGHT INTO THE AREA...ELEVATED INSTABILITY IS VERY
MARGINAL DUE TO THE LIMITED DEGREE OF THETA-E RETURN. SO CONTINUE
WITH NO THUNDER MENTION...BUT COULD SEE SOME GUSTIER SHOWERS
POTENTIALLY SUNDAY AFTERNOON AND EVE IF THE GFS/EC PAN OUT AS IS.
SO HAVE MENTIONED MORE OF A SHOWER WORDING DURING THE AFTERNOON
AND EVE BECAUSE OF THIS. TEMPERATURES ON SUNDAY COULD ENCOMPASS A
FAIRLY LARGE RANGE THANKS TO THE IMPACTS OF THE LIKELY RAIN. WITH
CONFIDENCE INCREASING IN RAIN...HAVE CONTINUED NOT TO INCREASE
TEMPERATURES DESPITE SOME GUIDANCE INDICATING WARMER IN SUCCESSIVE
RUNS.
THE GFS REMAINS CONSISTENT WITH HAVING ANOTHER UPPER
WAVE...ACTUALLY ALMOST A PART OF THE FIRST ONE...MOVE NORTHEAST
ACROSS THE OHIO RIVER VALLEY ON MONDAY NIGHT INTO TUESDAY. THE
08.00 EC TRENDED BACK AWAY FROM THIS...BUT HAS BEEN THE LESS
CONSISTENT MODEL. HAVE KEPT POPS ON TUE MAINLY IN SOUTHEAST AREAS
TO ACCOUNT FOR THIS WAVE. WHILE THIS COULD HAVE IMPACTS ON
TEMPERATURES ON TUE...A LOW-LEVEL THERMAL TONGUE IS PROJECTED TO
BE KNOCKING ON OUR DOOR FROM THE WEST AND SHOULD PROVIDE FOR ABOVE
TO WELL ABOVE NORMAL TEMPERATURES. THE STRONGEST SIGNAL FOR VERY
MILD READINGS AND A DRY ATMOSPHERIC COLUMN IS ON WED AT THIS TIME.
AS PREVIOUS SHIFT DID...LEAN THE FORECAST TOWARDS THE BETTER
PERFORMING EC IN THOSE TYPE OF REGIMES. HIGHS IN THE UPPER 60S
INTO THE 70S ARE CURRENTLY WHAT THIS BLENDED APPROACH PRODUCES
AND SEEMS TO MAKE SENSE. WHILE A FRONT IS PRESENTLY FORECAST TO
MOVE THROUGH SOMETIME LATER WED INTO THU OF NEXT WEEK...IT WOULD
SEEM LIKELY WITH THE PATTERN THAT ABOVE NORMAL TEMPERATURES
CONTINUE THROUGH THE LATTER PART OF NEXT WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* OCCASIONAL W/NW GUSTS TO 27KT...DIMINISHING TO ARND 12KT AFT
23Z.
* PSBL BKN CIGS AT 5KFT AGL BTWN 04-08Z.
BEACHLER
//DISCUSSION...UPDATED 20Z...
VISIBLE IMAGERY CONTINUES TO INDICATE THE BULK OF THE CLOUD COVER
HAS DRIFTED SOUTHEAST OF MOST NORTHERN IL/NORTHWEST IN
AIRFIELDS...WITH JUST A FEW LOCATIONS STILL REPORTING BKN CIGS.
HOWEVER...THIS WILL CONTINUE TO DIMINISH THROUGH THE AFTN. EXPECT
BY 23Z CIGS TO BE APPROACH FEW COVERAGE BUT REMAIN VFR. GUSTY
WINDS HAVE ALSO COME UP HIGHER TO ARND 25 TO 28 KT AT
TIMES...DIMINISHING TO ARND 12 KT AFTER SUNSET.
PREV DISCUSSION FROM 18Z...
VISIBLE IMAGERY SHOWS ABUNDANT CLOUDS ACROSS SOUTHERN IL
STRETCHING NORTHEAST THROUGH INDIANA AND LOWER MICHIGAN. NORTHERN
IL/NORTHWEST IN ARE ON THE BACK SIDE OF THIS CLOUD COVER...WITH
A FEW POCKETS OF SCT/BKN CIGS ARND 3KFT AGL NOTED. THE GENERAL
TREND HAS BEEN FOR IMPROVING CONDS TO VFR...AND MOST SFC OBS
SUPPORT THIS AS WELL. GUIDANCE CONTINUES TO SUGGEST CIGS WILL
IMPROVE TO FEW/SCT CONDS LATER THIS EVENING WITH WINDS STEADILY
DIMINISHING AS WELL TO NW/W WINDS ARND 10-12KT. ANOTHER UPPER
LEVEL SYSTEM MAY BRING BKN CIGS BACK TO FAR NORTHEAST IL/NORTHWEST
IN AIRFIELDS BTWN 04-08Z. THEN HIGH PRESSURE CONTINUES TO BUILD IN
FROM THE WEST AND SHOULD PROVIDE VFR CONDS THRU MUCH OF FRI. A FEW
POCKETS OF DIURNAL CUMULUS CLOUDS WILL BE POSSIBLE FRI
MIDDAY...HOWEVER SHUD REMAIN VFR CONDS.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND DIR/SPEED FORECAST.
* MEDIUM CONFIDENCE IN CIGS FORECAST THRU 23Z.
* HIGH CONFIDENCE IN CIGS AFT 23Z.
* HIGH CONFIDENCE IN ALL OTHER ELEMENTS.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT AND SATURDAY...VFR.
SUNDAY AND MONDAY...CHANCE OF RAIN. MVFR POSSIBLE.
TUESDAY...CHANCE OF RAIN AND MVFR EARLY...OTHERWISE VFR.
WEDNESDAY...VFR.
KREIN
&&
.MARINE...
227 PM CST
A COLD FRONT THAT MOVED THROUGH THE LAKES OVERNIGHT HAS SINCE
SLIPPED INTO THE THE OHIO VALLEY TODAY. CLEAR SKIES WITH
NORTHWESTERLY FLOW AND GOOD COLD AIR ADVECTION HAVE ALLOWED WINDS TO
INCREASE AND GUST THIS AFTERNOON. ORIGINALLY INHERITED A SMALL
CRAFT ADVISORY FOR THE INDY SHORES STARTING TONIGHT...BUT WITH THE
STRONG WINDS THIS AFTERNOON...DECIDED TO PULL THE START TIME UP AND
ALSO INCLUDE THE ILLINOIS SHORES AS WHRI2 WAS GUSTING TO 27 KTS. DO
EXPECT A LITTLE LULL IN THE WINDS LATE THIS AFTERNOON AND INTO THE
EVENING HOURS...BUT WITH ANOTHER FRONT APPROACHING
OVERNIGHT...EXPECT WINDS TO KICK BACK UP AND BRING ALL OF THE
NEARSHORE WATERS TO CRITERIA JUST FROM WINDS ALONE THIS EVENING.
WINDS WILL ALSO INCREASE TO GALE FORCE THIS EVENING AND INTO THE
EARLY MORNING HOURS FOR THE NORTHERN HALF OF THE LAKE AS A DEEPENING
LOW PRESSURE CORE SLIDES SOUTHEAST FROM WESTERN ONTARIO AND TO JUST
EAST OF MICHIGAN. WINDS WILL LIKELY INCREASE TO ABOVE 35 KTS FOR
MUCH OF THE NORTHERN HALF OF THE LAKE FROM THE 09Z TO ROUGHLY 12 TO
13Z HOUR. DUE TO THE INCREASED LIKELIHOOD OF GALES...DID HOIST A
GALE WARNING FOR THE OVERNIGHT HOURS. AS THE LOW PULLS OFF TO THE
SOUTHEAST...WINDS WILL DECREASE ACROSS THE ILLINOIS SHORES AND ALL
ADVISORY CRITERIA SHOULD ABATE BY FRIDAY AFTERNOON...AND THEN INTO
THE EARLY EVENING HOURS FOR INDIANA. HIGH PRESSURE WILL THEN SLIDE
BACK ACROSS THE LAKES INTO THE START OF THE WEEKEND. STRONG SOUTH
WINDS WILL AGAIN RETURN ACROSS THE LAKE SATURDAY...WITH THE NORTHERN
TIER OF THE LAKE AGAIN APPROACHING GALES MID MORNING AND CONTINUING
OVERNIGHT.
SHEA
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...3 AM FRIDAY TO 10 AM FRIDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...6 PM THURSDAY TO 9
PM FRIDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...6 PM THURSDAY TO 4
PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
226 PM CST THU MAR 8 2012
.DISCUSSION...
1008 AM CST
NO REAL ISSUES LATE THIS MORNING OR GOING INTO THE
AFTERNOON...WITH MINOR CHANGES TO POP/WX GRIDS AS RAIN HAS EXITED
THE CWA...AND SOME ADJUSTMENTS TO CLOUD TRENDS TODAY.
SURFACE TROUGH AND ASSOCIATED COLD FRONT HAVE SINCE SHIFTED
EAST/SOUTHEAST OF THE CWA THIS MORNING...AS HIGHER PRESSURE BUILDS
EAST WITH PRESSURE RISES NOTED ACROSS MUCH OF THE REGION THIS
HOUR. ALTHOUGH...MAIN RIDGE AXIS REMAINS TO THE WEST OVER THE
CENTRAL PLAINS AND APPEARS AS IF IT WILL REMAIN SITUATED TO THE
WEST WITH A FAIRLY TIGHT PRESSURE GRADIENT TO REMAIN OVER THE CWA
TODAY. THIS WILL OCCUR AS AN UPPER LEVEL TROUGH REMAINS
OVERHEAD...WITH A MID LEVEL SHORT WAVE TROUGH DROPPING SOUTHEAST
THROUGH THE UPPER MIDWEST...WHICH WILL PLAY A FACTOR WITH CLOUD
TRENDS TODAY. LOW LEVEL CLOUD COVER WILL CONTINUE TO SHIFT EAST
THROUGH THE SOUTHEAST PORTION OF THE CWA THROUGH MID DAY WITH A
PARTIAL CLEARING TREND EXPECTED THROUGH MID DAY. ALTHOUGH...WITH
COOLER AIR MOVING THROUGH...STEEPENING LOW LEVEL LAPSE RATES...AND
THE APPROACHING WAVE...A REDEVELOPMENT OF CU/STRATO CU WILL HELP
TO PROVIDE WHATEVER CLEAR SKIES ARE IN PLACE TO BECOME MORE PARTLY
SUNNY/CLOUDY THIS AFTERNOON. THIS DIURNAL CU WILL THEN DIMINISH
WITH A CLEARING TREND EXPECTED ONCE AGAIN LATE THIS AFTERNOON AND
EARLY EVENING.
EVENING SKIES GRIDS MAY NEED TO BE ADJUSTED FOR THE AFTERNOON
ISSUANCE...AS A QUICKLY APPROACHING COLD FRONTAL BOUNDARY MAY
PROVIDE ADDITIONAL CLOUD COVER LATE THIS EVENING BEFORE HIGH
PRESSURE MOVES OVERHEAD EARLY FRIDAY.
RODRIGUEZ
//PREV DISCUSSION...
307 AM CST
THE IMMEDIATE CONCERNS WITH THE FORECAST ARE WITH THE FALLING
TEMPERATURES...AS WELL AS CONTINUED POST FRONTAL SHOWERS AND EVEN
SOME THUNDER CHANCES THIS MORNING ACROSS THE SOUTHERN HALF OF THE
AREA. THEN ATTENTION TURNS TO RAIN POTENTIAL SUNDAY...FOLLOWED BY
THE TEMPERATURES NEXT WEEK AS A SIGNIFICANT WARM UP...OR RE-WARM UP
WE SHOULD SAY...LOOKS LIKELY.
FOR THE CURRENT SITUATION...A VERY WELL-DEFINED COLD FRONT IS
CLEARING THE FORECAST AREA EARLY THIS MORNING. ROBUSTLY WARM AIR
AHEAD OF THIS FEATURE HELPED CHICAGO BREAK THEIR RECORD WARM LOW
FOR YESTERDAY /54 DEGREES/. THE COMBINATION OF THE FRONTAL PASSAGE
AND RAIN TOOK TEMPERATURES DOWN AS MUCH AS 14 DEGREES IN ONE
HOUR AT SOME LOCATIONS. A GOOD PART OF THE SHOWER ACTIVITY IS
POST-FRONTAL...ASSOCIATED WITH ELEVATED MOISTURE TRANSPORT AND
STRONG CONVERGENCE ALONG THE BOUNDARY. ITS A GOOD THING A LOT OF
THIS IS POST FRONTAL...AS MORE SHOWER ACTIVITY AHEAD OF THE FRONT
COULD HAVE POTENTIALLY STEERED DOWN SOME OF THE 55 KT FLOW AT 1500
FT SEEN ON THE KLOT DOPPLER VELOCITY FOR HOURS AHEAD OF THE FRONT.
THE NORTHWEST WIND SPEEDS BEHIND THE FRONT ARE ACTUALLY QUITE A
BIT LOWER...GUSTING AT TIMES TO NEAR 25 MPH. THIS SHOULD CONTINUE
TO BE THE CASE INTO THIS AFTERNOON.
AN INTERESTING AREA OF ELEVATED CONVECTION IS SEEN IN NORTHERN MO
AS OF 300 AM HAVING ORIGINATED IN KS WITH A SHORT WAVE PER WATER
VAPOR ANALYSIS. THIS AREA CONTINUES TO GROW UPSCALE EAST
NORTHEAST...WELL BEHIND THE FRONT. RUC AND NAM CROSS SECTIONS
THROUGH THIS AREA SHOW STRONG MID-LEVEL FRONTOGENESIS AND A VERY
DEEP LAYER /AROUND 200 MB/ OF NEGATIVE EPV AND SLIGHTLY
DECREASING THETA-E...INDICATING CONVECTIVE INSTABILITY PRESENT.
THE RUC FORECAST FOR THE FORCING AND INSTABILITY...AND HRRR
PROJECTION OF REFLECTIVITY...SEEMS TO HAVE A STRONG HANDLE ON
THIS...WHILE MOST OTHER GUIDANCE DOES NOT. THIS AREA IS FORECAST
BY THE RUC/HRRR TO COME ACROSS THE SOUTHERN HALF OF THE FORECAST
AREA EARLY THIS MORNING. THE CONVECTIVE SIGNAL WEAKENS
SOMEWHAT...BUT STILL THINK ISOLATED TO SCATTERED THUNDER SHOULD BE
SEEN AT LEAST CLOSE IF NOT INTO THE SOUTHERN FORECAST AREA. THERE
COULD BE SOME SMALL HAIL WITH THIS GIVEN THE LOW WET BULB ZERO
VALUES. THIS SHOULD EXIT BY 10 AM TO NOON...WITH LINGERING CLOUDS
BEHIND THE FRONT ACROSS THE SOUTHERN AREA INTO EARLY TO MID
AFTERNOON.
COLD AIR ADVECTION BEHIND THE FRONT WILL UNDERCUT THE MORNING
CLOUDS AND SHOWERS IN THE SOUTH...HELPING TO KEEP TEMPERATURES
NEARLY STEADY OR EVEN CONTINUING TO FALL THROUGH MID-MORNING.
CLEARING BY LATE MORNING INTO AFTERNOON WILL ALLOW FOR SOME
REBOUND...BUT PROBABLY ONLY INTO THE LOWER TO MID 40S. CONFIDENCE
ON THE DEGREE OF RECOVERY IS SOMEWHAT LOW DUE TO WEIGHING THE COLD
AIR ADVECTION/CLOUD IMPACT THIS MORNING.
THE UPPER TROUGH OVER MN EARLY THIS MORNING WILL PASS OVER THE
GREAT LAKES AND BE RE-ENFORCED BY A STRONG JET MAX TO THE
NORTHWEST. THIS WILL HELP TO PUSH A SECONDARY COLD FRONT SOUTH
THROUGH THE AREA LATE THIS EVENING INTO OVERNIGHT. THIS LOOKS TO
REALLY SEND DEW POINTS DOWN AND POTENTIALLY TEMPERATURES FURTHER
TOO. THE COLD POCKET ASSOCIATED WITH THIS SHOULD DEVELOP SOME
STRATOCU TONIGHT ACROSS NORTHERN AND EASTERN AREAS THAT MAY
POTENTIALLY LINGER INTO FRI MORNING.
HIGH PRESSURE WILL THEN PREVAIL FRIDAY INTO EARLY SATURDAY...WITH
RETURN FLOW THEN SETTING UP FOR SATURDAY...WHICH SHOULD BE A
FAIRLY PLEASANT AND SUNNY DAY. THE WELL-ORGANIZED CLOSED UPPER
LOW OVER THE DESERT SOUTHWEST WILL DRIFT GRADUALLY NORTHEAST ON
SATURDAY...THEN BEGIN TO BECOME MORE NEUTRAL TO NEGATIVELY TILED
AS IT LIFTS OVER OUR AREA ON SUNDAY INTO SUNDAY NIGHT. THE
AMOUNT OF MOISTURE RETURN AHEAD OF THIS IS FAIRLY SHORT IN
DURATION...BUT IT CERTAINLY LOOKS TO BE DEEP ENOUGH AND WITHIN
STRONG ENOUGH ISENTROPIC LIFT FOR FAIRLY WIDESPREAD RAIN/SHOWERS
ON SUNDAY. HAVE CONTINUED TO INCH UP POPS. WHILE THE SYSTEM DRY
SLOT EVOLVES RIGHT INTO THE AREA...ELEVATED INSTABILITY IS VERY
MARGINAL DUE TO THE LIMITED DEGREE OF THETA-E RETURN. SO CONTINUE
WITH NO THUNDER MENTION...BUT COULD SEE SOME GUSTIER SHOWERS
POTENTIALLY SUNDAY AFTERNOON AND EVE IF THE GFS/EC PAN OUT AS IS.
SO HAVE MENTIONED MORE OF A SHOWER WORDING DURING THE AFTERNOON
AND EVE BECAUSE OF THIS. TEMPERATURES ON SUNDAY COULD ENCOMPASS A
FAIRLY LARGE RANGE THANKS TO THE IMPACTS OF THE LIKELY RAIN. WITH
CONFIDENCE INCREASING IN RAIN...HAVE CONTINUED NOT TO INCREASE
TEMPERATURES DESPITE SOME GUIDANCE INDICATING WARMER IN SUCCESSIVE
RUNS.
THE GFS REMAINS CONSISTENT WITH HAVING ANOTHER UPPER
WAVE...ACTUALLY ALMOST A PART OF THE FIRST ONE...MOVE NORTHEAST
ACROSS THE OHIO RIVER VALLEY ON MONDAY NIGHT INTO TUESDAY. THE
08.00 EC TRENDED BACK AWAY FROM THIS...BUT HAS BEEN THE LESS
CONSISTENT MODEL. HAVE KEPT POPS ON TUE MAINLY IN SOUTHEAST AREAS
TO ACCOUNT FOR THIS WAVE. WHILE THIS COULD HAVE IMPACTS ON
TEMPERATURES ON TUE...A LOW-LEVEL THERMAL TONGUE IS PROJECTED TO
BE KNOCKING ON OUR DOOR FROM THE WEST AND SHOULD PROVIDE FOR ABOVE
TO WELL ABOVE NORMAL TEMPERATURES. THE STRONGEST SIGNAL FOR VERY
MILD READINGS AND A DRY ATMOSPHERIC COLUMN IS ON WED AT THIS TIME.
AS PREVIOUS SHIFT DID...LEAN THE FORECAST TOWARDS THE BETTER
PERFORMING EC IN THOSE TYPE OF REGIMES. HIGHS IN THE UPPER 60S
INTO THE 70S ARE CURRENTLY WHAT THIS BLENDED APPROACH PRODUCES
AND SEEMS TO MAKE SENSE. WHILE A FRONT IS PRESENTLY FORECAST TO
MOVE THROUGH SOMETIME LATER WED INTO THU OF NEXT WEEK...IT WOULD
SEEM LIKELY WITH THE PATTERN THAT ABOVE NORMAL TEMPERATURES
CONTINUE THROUGH THE LATTER PART OF NEXT WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* OCCASIONAL W/NW GUSTS TO 27KT...DIMINISHING TO ARND 12KT AFT
23Z.
* PSBL BKN CIGS AT 5KFT AGL BTWN 04-08Z.
BEACHLER
//DISCUSSION...UPDATED 20Z...
VISIBLE IMAGERY CONTINUES TO INDICATE THE BULK OF THE CLOUD COVER
HAS DRIFTED SOUTHEAST OF MOST NORTHERN IL/NORTHWEST IN
AIRFIELDS...WITH JUST A FEW LOCATIONS STILL REPORTING BKN CIGS.
HOWEVER...THIS WILL CONTINUE TO DIMINISH THROUGH THE AFTN. EXPECT
BY 23Z CIGS TO BE APPROACH FEW COVERAGE BUT REMAIN VFR. GUSTY
WINDS HAVE ALSO COME UP HIGHER TO ARND 25 TO 28 KT AT
TIMES...DIMINISHING TO ARND 12 KT AFTER SUNSET.
PREV DISCUSSION FROM 18Z...
VISIBLE IMAGERY SHOWS ABUNDANT CLOUDS ACROSS SOUTHERN IL
STRETCHING NORTHEAST THROUGH INDIANA AND LOWER MICHIGAN. NORTHERN
IL/NORTHWEST IN ARE ON THE BACK SIDE OF THIS CLOUD COVER...WITH
A FEW POCKETS OF SCT/BKN CIGS ARND 3KFT AGL NOTED. THE GENERAL
TREND HAS BEEN FOR IMPROVING CONDS TO VFR...AND MOST SFC OBS
SUPPORT THIS AS WELL. GUIDANCE CONTINUES TO SUGGEST CIGS WILL
IMPROVE TO FEW/SCT CONDS LATER THIS EVENING WITH WINDS STEADILY
DIMINISHING AS WELL TO NW/W WINDS ARND 10-12KT. ANOTHER UPPER
LEVEL SYSTEM MAY BRING BKN CIGS BACK TO FAR NORTHEAST IL/NORTHWEST
IN AIRFIELDS BTWN 04-08Z. THEN HIGH PRESSURE CONTINUES TO BUILD IN
FROM THE WEST AND SHOULD PROVIDE VFR CONDS THRU MUCH OF FRI. A FEW
POCKETS OF DIURNAL CUMULUS CLOUDS WILL BE POSSIBLE FRI
MIDDAY...HOWEVER SHUD REMAIN VFR CONDS.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND DIR/SPEED FORECAST.
* MEDIUM CONFIDENCE IN CIGS FORECAST THRU 23Z.
* HIGH CONFIDENCE IN CIGS AFT 23Z.
* HIGH CONFIDENCE IN ALL OTHER ELEMENTS.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT AND SATURDAY...VFR.
SUNDAY AND MONDAY...CHANCE OF RAIN. MVFR POSSIBLE.
TUESDAY...CHANCE OF RAIN AND MVFR EARLY...OTHERWISE VFR.
WEDNESDAY...VFR.
KREIN
&&
.MARINE...
325 AM CST
SOUTHWEST GALES ARE FINALLY COMING TO AN END OVER THE LAKE! THE
COLD FRONT IS ALMOST THROUGH LAKE MICHIGAN...WITH THE
SOUTHEASTERN THIRD OF THE LAKE STILL AWAITING ITS ARRIVAL. WINDS
BEHIND THE COLD FRONT HAVE DIMINISHED AND TURNED WEST TO
NORTHWEST. THE ABRUPT CHANGE IN WIND SPEED AND DIRECTION HAS
HELPED WAVES QUICKLY DIMINISH IN THE NEAR SHORE ZONES...THEREFORE
NOT ISSUING A SMALL CRAFT ADVISORY FOR THIS MORNING. WINDS MAY
GUST TO 25 KT FOR THE NEXT COUPLE OF HOURS...BUT NOT LONG ENOUGH
TO WARRANT A SMALL CRAFT ADVISORY.
A WEAKENING LOW MOVES SOUTH OVER THE EASTERN GREAT LAKES AS THE HIGH
PRESSURE TO OUR WEST MOVES INTO SOUTHERN MINNESOTA. AS THE TWO
SYSTEMS MOVE CLOSER TOGETHER THE PRESSURE GRADIENT TIGHTENS
OVERHEAD. THAT COMBINED WITH STRONG PRESSURE RISES WILL CREATE
NORTHWEST GALES OVER THE NORTHERN TWO THIRDS OF THE LAKE LATE
TONIGHT. GALES WILL BEGIN TO DIMINISH FRIDAY MORNING AS THE HIGH
PRESSURE MOVES INTO THE IMMEDIATE AREA. THE HIGH WILL PASS OVER
THE LAKE LATE FRIDAY AFTERNOON INTO FRIDAY EVENING.
YET ANOTHER ROUND OF GALES IS POSSIBLE ON THE BACKSIDE OF THE HIGH
PRESSURE SATURDAY MORNING. LOW END GALES ARE EXPECTED OVER THE
CENTRAL THIRD OF THE LAKE...WITH GALES UP TO 40 KT LIKELY OVER THE
NORTHERN THIRD OF THE LAKE. NOT ANTICIPATING GALES OVER THE
SOUTHERN THIRD OF THE LAKE. GALES BEGIN TO DIMINISH SATURDAY
AFTERNOON AS THE HIGH PRESSURE PULLS AWAY TO THE EAST...HOWEVER
GALES OVER THE NORTHERN END OF THE LAKE LOOK LIKE THEY WILL PERSIST
INTO THE EVENING HOURS.
MODELS HAVE SIGNIFICANT DISCREPANCIES IN TIMING AND THE OVERALL
PATTERN FOR THE REMAINDER OF THE FORECAST...SO WHILE NO GALES ARE
FORECAST FOR NEXT WEEK...FORECAST CONFIDENCE IS LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...3 AM FRIDAY TO 9
PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1152 AM CST THU MAR 8 2012
.DISCUSSION...
1008 AM CST
NO REAL ISSUES LATE THIS MORNING OR GOING INTO THE
AFTERNOON...WITH MINOR CHANGES TO POP/WX GRIDS AS RAIN HAS EXITED
THE CWA...AND SOME ADJUSTMENTS TO CLOUD TRENDS TODAY.
SURFACE TROUGH AND ASSOCIATED COLD FRONT HAVE SINCE SHIFTED
EAST/SOUTHEAST OF THE CWA THIS MORNING...AS HIGHER PRESSURE BUILDS
EAST WITH PRESSURE RISES NOTED ACROSS MUCH OF THE REGION THIS
HOUR. ALTHOUGH...MAIN RIDGE AXIS REMAINS TO THE WEST OVER THE
CENTRAL PLAINS AND APPEARS AS IF IT WILL REMAIN SITUATED TO THE
WEST WITH A FAIRLY TIGHT PRESSURE GRADIENT TO REMAIN OVER THE CWA
TODAY. THIS WILL OCCUR AS AN UPPER LEVEL TROUGH REMAINS
OVERHEAD...WITH A MID LEVEL SHORT WAVE TROUGH DROPPING SOUTHEAST
THROUGH THE UPPER MIDWEST...WHICH WILL PLAY A FACTOR WITH CLOUD
TRENDS TODAY. LOW LEVEL CLOUD COVER WILL CONTINUE TO SHIFT EAST
THROUGH THE SOUTHEAST PORTION OF THE CWA THROUGH MID DAY WITH A
PARTIAL CLEARING TREND EXPECTED THROUGH MID DAY. ALTHOUGH...WITH
COOLER AIR MOVING THROUGH...STEEPENING LOW LEVEL LAPSE RATES...AND
THE APPROACHING WAVE...A REDEVELOPMENT OF CU/STRATO CU WILL HELP
TO PROVIDE WHATEVER CLEAR SKIES ARE IN PLACE TO BECOME MORE PARTLY
SUNNY/CLOUDY THIS AFTERNOON. THIS DIURNAL CU WILL THEN DIMINISH
WITH A CLEARING TREND EXPECTED ONCE AGAIN LATE THIS AFTERNOON AND
EARLY EVENING.
EVENING SKIES GRIDS MAY NEED TO BE ADJUSTED FOR THE AFTERNOON
ISSUANCE...AS A QUICKLY APPROACHING COLD FRONTAL BOUNDARY MAY
PROVIDE ADDITIONAL CLOUD COVER LATE THIS EVENING BEFORE HIGH
PRESSURE MOVES OVERHEAD EARLY FRIDAY.
RODRIGUEZ
//PREV DISCUSSION...
307 AM CST
THE IMMEDIATE CONCERNS WITH THE FORECAST ARE WITH THE FALLING
TEMPERATURES...AS WELL AS CONTINUED POST FRONTAL SHOWERS AND EVEN
SOME THUNDER CHANCES THIS MORNING ACROSS THE SOUTHERN HALF OF THE
AREA. THEN ATTENTION TURNS TO RAIN POTENTIAL SUNDAY...FOLLOWED BY
THE TEMPERATURES NEXT WEEK AS A SIGNIFICANT WARM UP...OR RE-WARM UP
WE SHOULD SAY...LOOKS LIKELY.
FOR THE CURRENT SITUATION...A VERY WELL-DEFINED COLD FRONT IS
CLEARING THE FORECAST AREA EARLY THIS MORNING. ROBUSTLY WARM AIR
AHEAD OF THIS FEATURE HELPED CHICAGO BREAK THEIR RECORD WARM LOW
FOR YESTERDAY /54 DEGREES/. THE COMBINATION OF THE FRONTAL PASSAGE
AND RAIN TOOK TEMPERATURES DOWN AS MUCH AS 14 DEGREES IN ONE
HOUR AT SOME LOCATIONS. A GOOD PART OF THE SHOWER ACTIVITY IS
POST-FRONTAL...ASSOCIATED WITH ELEVATED MOISTURE TRANSPORT AND
STRONG CONVERGENCE ALONG THE BOUNDARY. ITS A GOOD THING A LOT OF
THIS IS POST FRONTAL...AS MORE SHOWER ACTIVITY AHEAD OF THE FRONT
COULD HAVE POTENTIALLY STEERED DOWN SOME OF THE 55 KT FLOW AT 1500
FT SEEN ON THE KLOT DOPPLER VELOCITY FOR HOURS AHEAD OF THE FRONT.
THE NORTHWEST WIND SPEEDS BEHIND THE FRONT ARE ACTUALLY QUITE A
BIT LOWER...GUSTING AT TIMES TO NEAR 25 MPH. THIS SHOULD CONTINUE
TO BE THE CASE INTO THIS AFTERNOON.
AN INTERESTING AREA OF ELEVATED CONVECTION IS SEEN IN NORTHERN MO
AS OF 300 AM HAVING ORIGINATED IN KS WITH A SHORT WAVE PER WATER
VAPOR ANALYSIS. THIS AREA CONTINUES TO GROW UPSCALE EAST
NORTHEAST...WELL BEHIND THE FRONT. RUC AND NAM CROSS SECTIONS
THROUGH THIS AREA SHOW STRONG MID-LEVEL FRONTOGENESIS AND A VERY
DEEP LAYER /AROUND 200 MB/ OF NEGATIVE EPV AND SLIGHTLY
DECREASING THETA-E...INDICATING CONVECTIVE INSTABILITY PRESENT.
THE RUC FORECAST FOR THE FORCING AND INSTABILITY...AND HRRR
PROJECTION OF REFLECTIVITY...SEEMS TO HAVE A STRONG HANDLE ON
THIS...WHILE MOST OTHER GUIDANCE DOES NOT. THIS AREA IS FORECAST
BY THE RUC/HRRR TO COME ACROSS THE SOUTHERN HALF OF THE FORECAST
AREA EARLY THIS MORNING. THE CONVECTIVE SIGNAL WEAKENS
SOMEWHAT...BUT STILL THINK ISOLATED TO SCATTERED THUNDER SHOULD BE
SEEN AT LEAST CLOSE IF NOT INTO THE SOUTHERN FORECAST AREA. THERE
COULD BE SOME SMALL HAIL WITH THIS GIVEN THE LOW WET BULB ZERO
VALUES. THIS SHOULD EXIT BY 10 AM TO NOON...WITH LINGERING CLOUDS
BEHIND THE FRONT ACROSS THE SOUTHERN AREA INTO EARLY TO MID
AFTERNOON.
COLD AIR ADVECTION BEHIND THE FRONT WILL UNDERCUT THE MORNING
CLOUDS AND SHOWERS IN THE SOUTH...HELPING TO KEEP TEMPERATURES
NEARLY STEADY OR EVEN CONTINUING TO FALL THROUGH MID-MORNING.
CLEARING BY LATE MORNING INTO AFTERNOON WILL ALLOW FOR SOME
REBOUND...BUT PROBABLY ONLY INTO THE LOWER TO MID 40S. CONFIDENCE
ON THE DEGREE OF RECOVERY IS SOMEWHAT LOW DUE TO WEIGHING THE COLD
AIR ADVECTION/CLOUD IMPACT THIS MORNING.
THE UPPER TROUGH OVER MN EARLY THIS MORNING WILL PASS OVER THE
GREAT LAKES AND BE RE-ENFORCED BY A STRONG JET MAX TO THE
NORTHWEST. THIS WILL HELP TO PUSH A SECONDARY COLD FRONT SOUTH
THROUGH THE AREA LATE THIS EVENING INTO OVERNIGHT. THIS LOOKS TO
REALLY SEND DEW POINTS DOWN AND POTENTIALLY TEMPERATURES FURTHER
TOO. THE COLD POCKET ASSOCIATED WITH THIS SHOULD DEVELOP SOME
STRATOCU TONIGHT ACROSS NORTHERN AND EASTERN AREAS THAT MAY
POTENTIALLY LINGER INTO FRI MORNING.
HIGH PRESSURE WILL THEN PREVAIL FRIDAY INTO EARLY SATURDAY...WITH
RETURN FLOW THEN SETTING UP FOR SATURDAY...WHICH SHOULD BE A
FAIRLY PLEASANT AND SUNNY DAY. THE WELL-ORGANIZED CLOSED UPPER
LOW OVER THE DESERT SOUTHWEST WILL DRIFT GRADUALLY NORTHEAST ON
SATURDAY...THEN BEGIN TO BECOME MORE NEUTRAL TO NEGATIVELY TILED
AS IT LIFTS OVER OUR AREA ON SUNDAY INTO SUNDAY NIGHT. THE
AMOUNT OF MOISTURE RETURN AHEAD OF THIS IS FAIRLY SHORT IN
DURATION...BUT IT CERTAINLY LOOKS TO BE DEEP ENOUGH AND WITHIN
STRONG ENOUGH ISENTROPIC LIFT FOR FAIRLY WIDESPREAD RAIN/SHOWERS
ON SUNDAY. HAVE CONTINUED TO INCH UP POPS. WHILE THE SYSTEM DRY
SLOT EVOLVES RIGHT INTO THE AREA...ELEVATED INSTABILITY IS VERY
MARGINAL DUE TO THE LIMITED DEGREE OF THETA-E RETURN. SO CONTINUE
WITH NO THUNDER MENTION...BUT COULD SEE SOME GUSTIER SHOWERS
POTENTIALLY SUNDAY AFTERNOON AND EVE IF THE GFS/EC PAN OUT AS IS.
SO HAVE MENTIONED MORE OF A SHOWER WORDING DURING THE AFTERNOON
AND EVE BECAUSE OF THIS. TEMPERATURES ON SUNDAY COULD ENCOMPASS A
FAIRLY LARGE RANGE THANKS TO THE IMPACTS OF THE LIKELY RAIN. WITH
CONFIDENCE INCREASING IN RAIN...HAVE CONTINUED NOT TO INCREASE
TEMPERATURES DESPITE SOME GUIDANCE INDICATING WARMER IN SUCCESSIVE
RUNS.
THE GFS REMAINS CONSISTENT WITH HAVING ANOTHER UPPER
WAVE...ACTUALLY ALMOST A PART OF THE FIRST ONE...MOVE NORTHEAST
ACROSS THE OHIO RIVER VALLEY ON MONDAY NIGHT INTO TUESDAY. THE
08.00 EC TRENDED BACK AWAY FROM THIS...BUT HAS BEEN THE LESS
CONSISTENT MODEL. HAVE KEPT POPS ON TUE MAINLY IN SOUTHEAST AREAS
TO ACCOUNT FOR THIS WAVE. WHILE THIS COULD HAVE IMPACTS ON
TEMPERATURES ON TUE...A LOW-LEVEL THERMAL TONGUE IS PROJECTED TO
BE KNOCKING ON OUR DOOR FROM THE WEST AND SHOULD PROVIDE FOR ABOVE
TO WELL ABOVE NORMAL TEMPERATURES. THE STRONGEST SIGNAL FOR VERY
MILD READINGS AND A DRY ATMOSPHERIC COLUMN IS ON WED AT THIS TIME.
AS PREVIOUS SHIFT DID...LEAN THE FORECAST TOWARDS THE BETTER
PERFORMING EC IN THOSE TYPE OF REGIMES. HIGHS IN THE UPPER 60S
INTO THE 70S ARE CURRENTLY WHAT THIS BLENDED APPROACH PRODUCES
AND SEEMS TO MAKE SENSE. WHILE A FRONT IS PRESENTLY FORECAST TO
MOVE THROUGH SOMETIME LATER WED INTO THU OF NEXT WEEK...IT WOULD
SEEM LIKELY WITH THE PATTERN THAT ABOVE NORMAL TEMPERATURES
CONTINUE THROUGH THE LATTER PART OF NEXT WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* PATCHY BKN CIGS ARND 3000-3400FT AGL...LIFTING BY 23Z.
* OCCASIONAL W/NW GUSTS TO 24KT...DIMINISHING TO ARND 12KT AFT
23Z.
* PSBL BKN CIGS AT 5KFT AGL BTWN 04-08Z.
BEACHLER
//DISCUSSION...UPDATED 18Z...
VISIBLE IMAGERY SHOWS ABUNDANT CLOUDS ACROSS SOUTHERN IL
STRETCHING NORTHEAST THROUGH INDIANA AND LOWER MICHIGAN. NORTHERN
IL/NORTHWEST IN ARE ON THE BACK SIDE OF THIS CLOUD COVER...WITH
A FEW POCKETS OF SCT/BKN CIGS ARND 3KFT AGL NOTED. THE GENERAL
TREND HAS BEEN FOR IMPROVING CONDS TO VFR...AND MOST SFC OBS
SUPPORT THIS AS WELL. GUIDANCE CONTINUES TO SUGGEST CIGS WILL
IMPROVE TO FEW/SCT CONDS LATER THIS EVENING WITH WINDS STEADILY
DIMINISHING AS WELL TO NW/W WINDS ARND 10-12KT. ANOTHER UPPER
LEVEL SYSTEM MAY BRING BKN CIGS BACK TO FAR NORTHEAST IL/NORTHWEST
IN AIRFIELDS BTWN 04-08Z. THEN HIGH PRESSURE CONTINUES TO BUILD IN
FROM THE WEST AND SHOULD PROVIDE VFR CONDS THRU MUCH OF FRI. A FEW
POCKETS OF DIURNAL CUMULUS CLOUDS WILL BE POSSIBLE FRI
MIDDAY...HOWEVER SHUD REMAIN VFR CONDS.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND DIR/SPEED FORECAST.
* MEDIUM CONFIDENCE IN CIGS FORECAST THRU 23Z.
* HIGH CONFIDENCE IN CIGS AFT 23Z.
* HIGH CONFIDENCE IN ALL OTHER ELEMENTS.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT AND SATURDAY...VFR.
SUNDAY AND MONDAY...CHANCE OF RAIN. MVFR POSSIBLE.
TUESDAY...CHANCE OF RAIN AND MVFR EARLY...OTHERWISE VFR.
WEDNESDAY...VFR.
KREIN
&&
.MARINE...
325 AM CST
SOUTHWEST GALES ARE FINALLY COMING TO AN END OVER THE LAKE! THE
COLD FRONT IS ALMOST THROUGH LAKE MICHIGAN...WITH THE
SOUTHEASTERN THIRD OF THE LAKE STILL AWAITING ITS ARRIVAL. WINDS
BEHIND THE COLD FRONT HAVE DIMINISHED AND TURNED WEST TO
NORTHWEST. THE ABRUPT CHANGE IN WIND SPEED AND DIRECTION HAS
HELPED WAVES QUICKLY DIMINISH IN THE NEAR SHORE ZONES...THEREFORE
NOT ISSUING A SMALL CRAFT ADVISORY FOR THIS MORNING. WINDS MAY
GUST TO 25 KT FOR THE NEXT COUPLE OF HOURS...BUT NOT LONG ENOUGH
TO WARRANT A SMALL CRAFT ADVISORY.
A WEAKENING LOW MOVES SOUTH OVER THE EASTERN GREAT LAKES AS THE HIGH
PRESSURE TO OUR WEST MOVES INTO SOUTHERN MINNESOTA. AS THE TWO
SYSTEMS MOVE CLOSER TOGETHER THE PRESSURE GRADIENT TIGHTENS
OVERHEAD. THAT COMBINED WITH STRONG PRESSURE RISES WILL CREATE
NORTHWEST GALES OVER THE NORTHERN TWO THIRDS OF THE LAKE LATE
TONIGHT. GALES WILL BEGIN TO DIMINISH FRIDAY MORNING AS THE HIGH
PRESSURE MOVES INTO THE IMMEDIATE AREA. THE HIGH WILL PASS OVER
THE LAKE LATE FRIDAY AFTERNOON INTO FRIDAY EVENING.
YET ANOTHER ROUND OF GALES IS POSSIBLE ON THE BACKSIDE OF THE HIGH
PRESSURE SATURDAY MORNING. LOW END GALES ARE EXPECTED OVER THE
CENTRAL THIRD OF THE LAKE...WITH GALES UP TO 40 KT LIKELY OVER THE
NORTHERN THIRD OF THE LAKE. NOT ANTICIPATING GALES OVER THE
SOUTHERN THIRD OF THE LAKE. GALES BEGIN TO DIMINISH SATURDAY
AFTERNOON AS THE HIGH PRESSURE PULLS AWAY TO THE EAST...HOWEVER
GALES OVER THE NORTHERN END OF THE LAKE LOOK LIKE THEY WILL PERSIST
INTO THE EVENING HOURS.
MODELS HAVE SIGNIFICANT DISCREPANCIES IN TIMING AND THE OVERALL
PATTERN FOR THE REMAINDER OF THE FORECAST...SO WHILE NO GALES ARE
FORECAST FOR NEXT WEEK...FORECAST CONFIDENCE IS LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...3 AM FRIDAY TO 9
PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1040 AM CST THU MAR 8 2012
.DISCUSSION...
ISSUED 1040 AM CST THU MAR 8 2012
COLD FRONT HAS SETTLED SOUTHWARD INTO THE OHIO RIVER VALLEY THIS
MORNING...TAKING THE BULK OF THE RAIN WITH IT. A FEW LIGHT SHOWERS
LINGER TO THE NORTH OF THE BOUNDARY...WITH THE LATEST RADAR MOSAIC
SHOWING THE PRECIP MAINLY LOCATED ALONG AND SOUTH OF A LITCHFIELD
TO PARIS LINE. MID-LEVEL SHORT-WAVE CURRENTLY EVIDENT ON WATER VAPOR
IMAGERY OVER SOUTHERN MINNESOTA/NORTHERN IOWA WILL TRACK E/SE
ACROSS NORTHERN ILLINOIS THIS AFTERNOON...GRADUALLY PUSHING THE
FRONT AND PRECIP EVEN FURTHER SOUTH. HAVE UPDATED FORECAST TO
CARRY SCATTERED SHOWERS SOUTH OF THE I-72 CORRIDOR THROUGH
MID-AFTERNOON...THEN WENT DRY ACROSS THE BOARD AFTER 21Z. AS WAVE
MOVES BY TO THE NORTH...DRIER AIR WILL BRING CLEARING SKIES TO THE
CENTRAL AND NORTHERN KILX CWA AS THE DAY PROGRESSES...WITH
OVERCAST CONDITIONS PERSISTING ALONG/SOUTH OF I-70. ZONE UPDATE
WILL BE ISSUED SHORTLY.
BARNES
&&
.AVIATION...
ISSUED 516 AM CST THU MAR 8 2012
COLD FRONT HAS PASSED THROUGH THE TAF SITES THIS MORNING...WITH A
BRIEF LULL IN THE PRECIPITATION. SHOWERS WILL RAMP UP AGAIN EARLY AS
A SHORTWAVE MOVES FROM NORTHERN MO ACROSS CENTRAL IL. SINCE
LIGHTNING HAS DECREASED IN THE PAST COUPLE OF HOURS...WILL JUST HAVE
SOME VCTS IN THE MORNING. PRECIPITATION MAY MIX WITH LIGHT SNOW OR
LIGHT SLEET AT PIA AS TEMPERATURES FALL THROUGH THE 30S ON THE BACK
EDGE OF THE RAIN SHIELD. THE LATEST RUN OF THE HRRR MODEL HAS A
DECENT HANDLE ON THE CURRENT WEATHER...SO WILL FOLLOW THIS AND
EXPECT PRECIPITATION TO END AT PIA 15Z-16Z...AND AT CMI AROUND 18Z.
CEILINGS/FLIGHT RULES VARY WIDELY OVER THE AREA THIS MORNING...BUT
EXPECT GENERAL MVFR CONDITIONS WITH POSSIBLY IFR IN HEAVIER SHOWERS.
OVERALL EXPECT IMPROVEMENT TO VFR A COUPLE OF HOURS AFTER
PRECIPITATION ENDS...THEN MAINLY CLEAR SKIES BY 00Z FRI. NORTHWEST
WINDS WILL STILL BE ON THE STRONG SIDE TODAY WITH 18-22 KT SUSTAINED
WITH GUSTS ABOVE 30 KT AT TIMES. WINDS WILL THEN DIMINISH AND BACK
TO WESTERLY AFTER 00Z FRI.
04
&&
.PREV DISCUSSION...
ISSUED 314 AM CST THU MAR 8 2012
COLD FRONT PUSHING THROUGH THE FORECAST AREA THIS MORNING WITH SOME
SHOWERS OUT AHEAD AND ALONG. A SECOND ROUND OF SHOWERS AND
OCCASIONAL THUNDER PUSHING UP JUST BEHIND THE SFC BOUNDARY AS A WAVE
MOVES NE INTO THE REGION. MORNING PRECIP AND HOW LONG IT WILL IMPACT
THE REGION IS THE FIRST ISSUE...ALONG WITH THE HOURLY TEMPS THIS
MORNING AS COLDER AIR MOVES INTO THE AREA. BEYOND THAT...THE
FORECAST HAS FEW CHANGES AS THE MODELS STILL WORK OUT HOW THE MAIN
UPPER LOW OVER THE SWRN CONUS IS GOING TO MOVE OUT AND ACROSS THE
ERN HALF OF THE COUNTRY. STILL MORE IN FAVOR OF THE ECMWF...AND HAVE
TRIED TO MITIGATE THE GFS IMPACTS IN THE EXTENDED AS MUCH AS
COLLABORATION AND CONSENSUS WOULD ALLOW. THAT BEING SAID...THE GFS
SOLUTION OF SPLITTING THE WAVE INTO SEVERAL SMALLER WAVES IS SLOWLY
TURNING INTO A MORE ECMWF/NAM SOLUTION. BIGGEST IMPACT FOR THIS
PARTICULAR DISCREPANCY WILL BE ON MON NIGHT/TUESDAY WHERE THE
CONFIDENCE IN THE GOING FORECAST DECREASES.
SHORT TERM...TODAY AND TOMORROW...
HIGH TEMPERATURES LIKELY TO BE MET EARLY AS THE REMAINDER OF THE DAY
WILL BE COOLER WITH THE FRONT PASSING THROUGH THIS MORNING. PRECIP
WILL CONTINUE WITH A CHANCE FOR SOME THUNDER THIS MORNING WITH SOME
STEEPER MID LEVEL LAPSE RATES ASSOCIATED WITH THE WAVE MOVING
THROUGH THE FLOW JUST BEHIND THE SFC BOUNDARY. POPS DECREASING NW TO
SE AFTER 18Z. TEMPS A BIT COOLER TONIGHT. CONCERN THAT GUIDANCE AND
GOING FORECAST ARE NOT QUITE COOL ENOUGH SHOULD THE SKIES CLEAR A
BIT MORE QUICKLY THAN THE MODEL RH PROFILES ARE HINTING. RATHER DRY
AIR AVAILABLE BEHIND THIS WAVE. TOMORROW...TEMPS COOLER THAN LAST
COUPLE OF DAYS...BUT STILL A BIT WARMER THAN SEASONABLE...UPPER
40S/NEAR 50 WITH PLENTY OF SUNSHINE.
LONG TERM...SATURDAY THROUGH WEDNESDAY...
WINDS COME AROUND TO MORE SOUTHERLY SATURDAY MORNING...AND ASSISTS
IN A WARM UP WITH PLENTY OF SUNSHINE EARLY. HOWEVER...SOME OF THIS
WARM UP WILL BE SHORT LIVED AS A DEVELOPING SYSTEM MOVES OUT OF THE
SRN PLAINS INTO THE MIDWEST. MODELS HAVE HAD QUITE THE HISTORY WITH
THIS SYSTEM...AND MANY MANY DIFFERENT SOLUTIONS. FOR NOW...THE EC IS
PUSHING THE SYSTEM THROUGH...RATHER DIFFUSE AS AN OPEN WAVE...AND
WEAKENING AND LESSENING THE QPF TRENDS IN THE LAST COUPLE OF RUNS.
THE GFS IS ALSO EASING A BIT...BUT DELIVERING THE PRECIP IN A ONE
TWO PUNCH FOR SAT NIGHT/SUN AND MON NIGHT/TUES. FOR NOW...BEST
CHANCES FOR POPS ARE IN THE FORECAST WITH SUNDAY AND SUNDAY NIGHT.
FROM TUES NIGHT THROUGH WED...KEEPING THE FORECAST DRY AT THIS POINT
AS THE MODELS ARE STRUGGLING WITH A BIT OF FEEDBACK IN WEAK SWRLY
FLOW.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1014 AM CST THU MAR 8 2012
.DISCUSSION...
1008 AM CST
NO REAL ISSUES LATE THIS MORNING OR GOING INTO THE
AFTERNOON...WITH MINOR CHANGES TO POP/WX GRIDS AS RAIN HAS EXITED
THE CWA...AND SOME ADJUSTMENTS TO CLOUD TRENDS TODAY.
SURFACE TROUGH AND ASSOCIATED COLD FRONT HAVE SINCE SHIFTED
EAST/SOUTHEAST OF THE CWA THIS MORNING...AS HIGHER PRESSURE BUILDS
EAST WITH PRESSURE RISES NOTED ACROSS MUCH OF THE REGION THIS
HOUR. ALTHOUGH...MAIN RIDGE AXIS REMAINS TO THE WEST OVER THE
CENTRAL PLAINS AND APPEARS AS IF IT WILL REMAIN SITUATED TO THE
WEST WITH A FAIRLY TIGHT PRESSURE GRADIENT TO REMAIN OVER THE CWA
TODAY. THIS WILL OCCUR AS AN UPPER LEVEL TROUGH REMAINS
OVERHEAD...WITH A MID LEVEL SHORT WAVE TROUGH DROPPING SOUTHEAST
THROUGH THE UPPER MIDWEST...WHICH WILL PLAY A FACTOR WITH CLOUD
TRENDS TODAY. LOW LEVEL CLOUD COVER WILL CONTINUE TO SHIFT EAST
THROUGH THE SOUTHEAST PORTION OF THE CWA THROUGH MID DAY WITH A
PARTIAL CLEARING TREND EXPECTED THROUGH MID DAY. ALTHOUGH...WITH
COOLER AIR MOVING THROUGH...STEEPENING LOW LEVEL LAPSE RATES...AND
THE APPROACHING WAVE...A REDEVELOPMENT OF CU/STRATO CU WILL HELP
TO PROVIDE WHATEVER CLEAR SKIES ARE IN PLACE TO BECOME MORE PARTLY
SUNNY/CLOUDY THIS AFTERNOON. THIS DIURNAL CU WILL THEN DIMINISH
WITH A CLEARING TREND EXPECTED ONCE AGAIN LATE THIS AFTERNOON AND
EARLY EVENING.
EVENING SKIES GRIDS MAY NEED TO BE ADJUSTED FOR THE AFTERNOON
ISSUANCE...AS A QUICKLY APPROACHING COLD FRONTAL BOUNDARY MAY
PROVIDE ADDITIONAL CLOUD COVER LATE THIS EVENING BEFORE HIGH
PRESSURE MOVES OVERHEAD EARLY FRIDAY.
RODRIGUEZ
//PREV DISCUSSION...
307 AM CST
THE IMMEDIATE CONCERNS WITH THE FORECAST ARE WITH THE FALLING
TEMPERATURES...AS WELL AS CONTINUED POST FRONTAL SHOWERS AND EVEN
SOME THUNDER CHANCES THIS MORNING ACROSS THE SOUTHERN HALF OF THE
AREA. THEN ATTENTION TURNS TO RAIN POTENTIAL SUNDAY...FOLLOWED BY
THE TEMPERATURES NEXT WEEK AS A SIGNIFICANT WARM UP...OR RE-WARM UP
WE SHOULD SAY...LOOKS LIKELY.
FOR THE CURRENT SITUATION...A VERY WELL-DEFINED COLD FRONT IS
CLEARING THE FORECAST AREA EARLY THIS MORNING. ROBUSTLY WARM AIR
AHEAD OF THIS FEATURE HELPED CHICAGO BREAK THEIR RECORD WARM LOW
FOR YESTERDAY /54 DEGREES/. THE COMBINATION OF THE FRONTAL PASSAGE
AND RAIN TOOK TEMPERATURES DOWN AS MUCH AS 14 DEGREES IN ONE
HOUR AT SOME LOCATIONS. A GOOD PART OF THE SHOWER ACTIVITY IS
POST-FRONTAL...ASSOCIATED WITH ELEVATED MOISTURE TRANSPORT AND
STRONG CONVERGENCE ALONG THE BOUNDARY. ITS A GOOD THING A LOT OF
THIS IS POST FRONTAL...AS MORE SHOWER ACTIVITY AHEAD OF THE FRONT
COULD HAVE POTENTIALLY STEERED DOWN SOME OF THE 55 KT FLOW AT 1500
FT SEEN ON THE KLOT DOPPLER VELOCITY FOR HOURS AHEAD OF THE FRONT.
THE NORTHWEST WIND SPEEDS BEHIND THE FRONT ARE ACTUALLY QUITE A
BIT LOWER...GUSTING AT TIMES TO NEAR 25 MPH. THIS SHOULD CONTINUE
TO BE THE CASE INTO THIS AFTERNOON.
AN INTERESTING AREA OF ELEVATED CONVECTION IS SEEN IN NORTHERN MO
AS OF 300 AM HAVING ORIGINATED IN KS WITH A SHORT WAVE PER WATER
VAPOR ANALYSIS. THIS AREA CONTINUES TO GROW UPSCALE EAST
NORTHEAST...WELL BEHIND THE FRONT. RUC AND NAM CROSS SECTIONS
THROUGH THIS AREA SHOW STRONG MID-LEVEL FRONTOGENESIS AND A VERY
DEEP LAYER /AROUND 200 MB/ OF NEGATIVE EPV AND SLIGHTLY
DECREASING THETA-E...INDICATING CONVECTIVE INSTABILITY PRESENT.
THE RUC FORECAST FOR THE FORCING AND INSTABILITY...AND HRRR
PROJECTION OF REFLECTIVITY...SEEMS TO HAVE A STRONG HANDLE ON
THIS...WHILE MOST OTHER GUIDANCE DOES NOT. THIS AREA IS FORECAST
BY THE RUC/HRRR TO COME ACROSS THE SOUTHERN HALF OF THE FORECAST
AREA EARLY THIS MORNING. THE CONVECTIVE SIGNAL WEAKENS
SOMEWHAT...BUT STILL THINK ISOLATED TO SCATTERED THUNDER SHOULD BE
SEEN AT LEAST CLOSE IF NOT INTO THE SOUTHERN FORECAST AREA. THERE
COULD BE SOME SMALL HAIL WITH THIS GIVEN THE LOW WET BULB ZERO
VALUES. THIS SHOULD EXIT BY 10 AM TO NOON...WITH LINGERING CLOUDS
BEHIND THE FRONT ACROSS THE SOUTHERN AREA INTO EARLY TO MID
AFTERNOON.
COLD AIR ADVECTION BEHIND THE FRONT WILL UNDERCUT THE MORNING
CLOUDS AND SHOWERS IN THE SOUTH...HELPING TO KEEP TEMPERATURES
NEARLY STEADY OR EVEN CONTINUING TO FALL THROUGH MID-MORNING.
CLEARING BY LATE MORNING INTO AFTERNOON WILL ALLOW FOR SOME
REBOUND...BUT PROBABLY ONLY INTO THE LOWER TO MID 40S. CONFIDENCE
ON THE DEGREE OF RECOVERY IS SOMEWHAT LOW DUE TO WEIGHING THE COLD
AIR ADVECTION/CLOUD IMPACT THIS MORNING.
THE UPPER TROUGH OVER MN EARLY THIS MORNING WILL PASS OVER THE
GREAT LAKES AND BE RE-ENFORCED BY A STRONG JET MAX TO THE
NORTHWEST. THIS WILL HELP TO PUSH A SECONDARY COLD FRONT SOUTH
THROUGH THE AREA LATE THIS EVENING INTO OVERNIGHT. THIS LOOKS TO
REALLY SEND DEW POINTS DOWN AND POTENTIALLY TEMPERATURES FURTHER
TOO. THE COLD POCKET ASSOCIATED WITH THIS SHOULD DEVELOP SOME
STRATOCU TONIGHT ACROSS NORTHERN AND EASTERN AREAS THAT MAY
POTENTIALLY LINGER INTO FRI MORNING.
HIGH PRESSURE WILL THEN PREVAIL FRIDAY INTO EARLY SATURDAY...WITH
RETURN FLOW THEN SETTING UP FOR SATURDAY...WHICH SHOULD BE A
FAIRLY PLEASANT AND SUNNY DAY. THE WELL-ORGANIZED CLOSED UPPER
LOW OVER THE DESERT SOUTHWEST WILL DRIFT GRADUALLY NORTHEAST ON
SATURDAY...THEN BEGIN TO BECOME MORE NEUTRAL TO NEGATIVELY TILED
AS IT LIFTS OVER OUR AREA ON SUNDAY INTO SUNDAY NIGHT. THE
AMOUNT OF MOISTURE RETURN AHEAD OF THIS IS FAIRLY SHORT IN
DURATION...BUT IT CERTAINLY LOOKS TO BE DEEP ENOUGH AND WITHIN
STRONG ENOUGH ISENTROPIC LIFT FOR FAIRLY WIDESPREAD RAIN/SHOWERS
ON SUNDAY. HAVE CONTINUED TO INCH UP POPS. WHILE THE SYSTEM DRY
SLOT EVOLVES RIGHT INTO THE AREA...ELEVATED INSTABILITY IS VERY
MARGINAL DUE TO THE LIMITED DEGREE OF THETA-E RETURN. SO CONTINUE
WITH NO THUNDER MENTION...BUT COULD SEE SOME GUSTIER SHOWERS
POTENTIALLY SUNDAY AFTERNOON AND EVE IF THE GFS/EC PAN OUT AS IS.
SO HAVE MENTIONED MORE OF A SHOWER WORDING DURING THE AFTERNOON
AND EVE BECAUSE OF THIS. TEMPERATURES ON SUNDAY COULD ENCOMPASS A
FAIRLY LARGE RANGE THANKS TO THE IMPACTS OF THE LIKELY RAIN. WITH
CONFIDENCE INCREASING IN RAIN...HAVE CONTINUED NOT TO INCREASE
TEMPERATURES DESPITE SOME GUIDANCE INDICATING WARMER IN SUCCESSIVE
RUNS.
THE GFS REMAINS CONSISTENT WITH HAVING ANOTHER UPPER
WAVE...ACTUALLY ALMOST A PART OF THE FIRST ONE...MOVE NORTHEAST
ACROSS THE OHIO RIVER VALLEY ON MONDAY NIGHT INTO TUESDAY. THE
08.00 EC TRENDED BACK AWAY FROM THIS...BUT HAS BEEN THE LESS
CONSISTENT MODEL. HAVE KEPT POPS ON TUE MAINLY IN SOUTHEAST AREAS
TO ACCOUNT FOR THIS WAVE. WHILE THIS COULD HAVE IMPACTS ON
TEMPERATURES ON TUE...A LOW-LEVEL THERMAL TONGUE IS PROJECTED TO
BE KNOCKING ON OUR DOOR FROM THE WEST AND SHOULD PROVIDE FOR ABOVE
TO WELL ABOVE NORMAL TEMPERATURES. THE STRONGEST SIGNAL FOR VERY
MILD READINGS AND A DRY ATMOSPHERIC COLUMN IS ON WED AT THIS TIME.
AS PREVIOUS SHIFT DID...LEAN THE FORECAST TOWARDS THE BETTER
PERFORMING EC IN THOSE TYPE OF REGIMES. HIGHS IN THE UPPER 60S
INTO THE 70S ARE CURRENTLY WHAT THIS BLENDED APPROACH PRODUCES
AND SEEMS TO MAKE SENSE. WHILE A FRONT IS PRESENTLY FORECAST TO
MOVE THROUGH SOMETIME LATER WED INTO THU OF NEXT WEEK...IT WOULD
SEEM LIKELY WITH THE PATTERN THAT ABOVE NORMAL TEMPERATURES
CONTINUE THROUGH THE LATTER PART OF NEXT WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* MVFR CIGS LINGER...ALTHOUGH STEADILY LIFTING TOWARDS VFR CIGS BY
THIS AFTN.
* OCCASIONAL W/NW GUSTS TO 25KT THRU THIS AFTN...THEN DIMINISHING.
BEACHLER
//DISCUSSION...UPDATED 12Z...
A STRONG COLD FRONT HAS PUSHED EAST OF THE TERMINALS THIS MORNING.
WITH THE FROPA...WINDS HAVE SHIFTED TO NWLY AND DIMINISHED
SOMEWHAT...THOUGH GUSTS TO 25KT ARE LIKELY THROUGH THE DAY. MUCH
OF THE ASSOCIATED PCPN HAS ENDED...BUT AN UPPER LEVEL IMPULSE
MOVING THROUGH CNTRL IL HAS BROUGHT MORE RAIN AND SOME ISOLD
THUNDER...BUT LATEST RADAR IMAGERY INDICATES A WEAKENING TREND AND
IT IS LIKELY THAT ANY REMAINING PRECIP SHOULD REMAIN SOUTH OF THE
TERMINALS...WITH THE POSSIBLE EXCEPTION OF KGYY WHICH MAY STILL
GET CLIPPED WITH SOME SHRA. OTHERWISE...THE TREND FOR THE DAY
SHOULD BE FOR IMPROVING CIGS AS COOLER...DRIER AIR FILTERS IN
BEHIND THE COLD FRONT. EXPECT THAT CIGS SHOULD IMPROVE TO VFR BY
LATE MORNING. THE REMAINDER OF THE PERIOD SHOULD SEE VFR
CONDITIONS AS HIGH PRESSURE BUILDS ACROSS THE REGION. A WEAK LOW
PRESSURE SYSTEM MOVING THROUGH THE UPPER GREAT LAKES TONIGHT
SHOULD DRAG A SECONDARY COLD FRONT ACROSS THE AREA...BRINGING A
REINFORCING SHOT OF COLD AIR. THIS COLD ADVECTION SHOULD BRING
ANOTHER ROUND OF GUSTINESS DURG THE OVERNIGHT HOURS...THOUGH DO
NOT EXPECT GUSTS TO EXCEED 25KT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN WIND DIR/SPEED FORECAST.
* MEDIUM CONFIDENCE IN TIMING OF VFR CIGS DEVELOPING.
* HIGH CONFIDENCE IN ALL ELEMENTS AFT 21Z.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT AND SATURDAY...VFR.
SUNDAY AND MONDAY...CHANCE OF RAIN. MVFR POSSIBLE.
TUESDAY...CHANCE OF RAIN AND MVFR EARLY...OTHERWISE VFR.
WEDNESDAY...VFR.
KREIN
&&
.MARINE...
325 AM CST
SOUTHWEST GALES ARE FINALLY COMING TO AN END OVER THE LAKE! THE
COLD FRONT IS ALMOST THROUGH LAKE MICHIGAN...WITH THE
SOUTHEASTERN THIRD OF THE LAKE STILL AWAITING ITS ARRIVAL. WINDS
BEHIND THE COLD FRONT HAVE DIMINISHED AND TURNED WEST TO
NORTHWEST. THE ABRUPT CHANGE IN WIND SPEED AND DIRECTION HAS
HELPED WAVES QUICKLY DIMINISH IN THE NEAR SHORE ZONES...THEREFORE
NOT ISSUING A SMALL CRAFT ADVISORY FOR THIS MORNING. WINDS MAY
GUST TO 25 KT FOR THE NEXT COUPLE OF HOURS...BUT NOT LONG ENOUGH
TO WARRANT A SMALL CRAFT ADVISORY.
A WEAKENING LOW MOVES SOUTH OVER THE EASTERN GREAT LAKES AS THE HIGH
PRESSURE TO OUR WEST MOVES INTO SOUTHERN MINNESOTA. AS THE TWO
SYSTEMS MOVE CLOSER TOGETHER THE PRESSURE GRADIENT TIGHTENS
OVERHEAD. THAT COMBINED WITH STRONG PRESSURE RISES WILL CREATE
NORTHWEST GALES OVER THE NORTHERN TWO THIRDS OF THE LAKE LATE
TONIGHT. GALES WILL BEGIN TO DIMINISH FRIDAY MORNING AS THE HIGH
PRESSURE MOVES INTO THE IMMEDIATE AREA. THE HIGH WILL PASS OVER
THE LAKE LATE FRIDAY AFTERNOON INTO FRIDAY EVENING.
YET ANOTHER ROUND OF GALES IS POSSIBLE ON THE BACKSIDE OF THE HIGH
PRESSURE SATURDAY MORNING. LOW END GALES ARE EXPECTED OVER THE
CENTRAL THIRD OF THE LAKE...WITH GALES UP TO 40 KT LIKELY OVER THE
NORTHERN THIRD OF THE LAKE. NOT ANTICIPATING GALES OVER THE
SOUTHERN THIRD OF THE LAKE. GALES BEGIN TO DIMINISH SATURDAY
AFTERNOON AS THE HIGH PRESSURE PULLS AWAY TO THE EAST...HOWEVER
GALES OVER THE NORTHERN END OF THE LAKE LOOK LIKE THEY WILL PERSIST
INTO THE EVENING HOURS.
MODELS HAVE SIGNIFICANT DISCREPANCIES IN TIMING AND THE OVERALL
PATTERN FOR THE REMAINDER OF THE FORECAST...SO WHILE NO GALES ARE
FORECAST FOR NEXT WEEK...FORECAST CONFIDENCE IS LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...3 AM FRIDAY TO 9
PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1009 AM CST THU MAR 8 2012
.DISCUSSION...
1008 AM CST
NO REAL ISSUES LATE THIS MORNING OR GOING INTO THE
AFTERNOON...WITH MINOR CHANGES TO POP/WX GRIDS AS RAIN HAS EXITED
THE CWA...AND SOME ADJUSTMENTS TO CLOUD TRENDS TODAY.
SURFACE TROUGH AND ASSOCIATED COLD FRONT HAVE SINCE SHIFTED
EAST/SOUTHEAST OF THE CWA THIS MORNING...AS HIGHER PRESSURE BUILDS
EAST WITH PRESSURE RISES NOTED ACROSS MUCH OF THE REGION THIS
HOUR. ALTHOUGH...MAIN RIDGE AXIS REMAINS TO THE WEST OVER THE
CENTRAL PLAINS AND APPEARS AS IF IT WILL REMAIN SITUATED TO THE
WEST WITH A FAIRLY TIGHT PRESSURE GRADIENT TO REMAIN OVER THE CWA
TODAY. THIS WILL OCCUR AS AN UPPER LEVEL TROUGH REMAINS
OVERHEAD...WITH A MID LEVEL SHORT WAVE TROUGH DROPPING SOUTHEAST
THROUGH THE UPPER MIDWEST...WHICH WILL PLAY A FACTOR WITH CLOUD
TRENDS TODAY. LOW LEVEL CLOUD COVER WILL CONTINUE TO SHIFT EAST
THROUGH THE SOUTHEAST PORTION OF THE CWA THROUGH MID DAY WITH A
PARTIAL CLEARING TREND EXPECTED THROUGH MID DAY. ALTHOUGH...WITH
COOLER AIR MOVING THROUGH...STEEPENING LOW LEVEL LAPSE RATES...AND
THE APPROACHING WAVE...A REDEVELOPMENT OF CU/STRATO CU WILL HELP
TO PROVIDE WHATEVER CLEAR SKIES ARE IN PLACE TO BECOME MORE PARTLY
SUNNY/CLOUDY THIS AFTERNOON. THIS DIURNAL CU WILL THEN DIMINISH
WITH A CLEARING TREND EXPECTED ONCE AGAIN LATE THIS AFTERNOON AND
EARLY EVENING.
EVENING SKIES GRIDS MAY NEED TO BE ADJUSTED FOR THE AFTERNOON
ISSUANCE...AS A QUICKLY APPROACHING COLD FRONTAL BOUNDARY MAY
PROVIDE ADDITIONAL CLOUD COVER LATE THIS EVENING BEFORE HIGH
PRESSURE MOVES OVERHEAD EARLY FRIDAY.
RODRIGUEZ
&&
.PREV DISCUSSION...
307 AM CST
THE IMMEDIATE CONCERNS WITH THE FORECAST ARE WITH THE FALLING
TEMPERATURES...AS WELL AS CONTINUED POST FRONTAL SHOWERS AND EVEN
SOME THUNDER CHANCES THIS MORNING ACROSS THE SOUTHERN HALF OF THE
AREA. THEN ATTENTION TURNS TO RAIN POTENTIAL SUNDAY...FOLLOWED BY
THE TEMPERATURES NEXT WEEK AS A SIGNIFICANT WARM UP...OR RE-WARM UP
WE SHOULD SAY...LOOKS LIKELY.
FOR THE CURRENT SITUATION...A VERY WELL-DEFINED COLD FRONT IS
CLEARING THE FORECAST AREA EARLY THIS MORNING. ROBUSTLY WARM AIR
AHEAD OF THIS FEATURE HELPED CHICAGO BREAK THEIR RECORD WARM LOW
FOR YESTERDAY /54 DEGREES/. THE COMBINATION OF THE FRONTAL PASSAGE
AND RAIN TOOK TEMPERATURES DOWN AS MUCH AS 14 DEGREES IN ONE
HOUR AT SOME LOCATIONS. A GOOD PART OF THE SHOWER ACTIVITY IS
POST-FRONTAL...ASSOCIATED WITH ELEVATED MOISTURE TRANSPORT AND
STRONG CONVERGENCE ALONG THE BOUNDARY. ITS A GOOD THING A LOT OF
THIS IS POST FRONTAL...AS MORE SHOWER ACTIVITY AHEAD OF THE FRONT
COULD HAVE POTENTIALLY STEERED DOWN SOME OF THE 55 KT FLOW AT 1500
FT SEEN ON THE KLOT DOPPLER VELOCITY FOR HOURS AHEAD OF THE FRONT.
THE NORTHWEST WIND SPEEDS BEHIND THE FRONT ARE ACTUALLY QUITE A
BIT LOWER...GUSTING AT TIMES TO NEAR 25 MPH. THIS SHOULD CONTINUE
TO BE THE CASE INTO THIS AFTERNOON.
AN INTERESTING AREA OF ELEVATED CONVECTION IS SEEN IN NORTHERN MO
AS OF 300 AM HAVING ORIGINATED IN KS WITH A SHORT WAVE PER WATER
VAPOR ANALYSIS. THIS AREA CONTINUES TO GROW UPSCALE EAST
NORTHEAST...WELL BEHIND THE FRONT. RUC AND NAM CROSS SECTIONS
THROUGH THIS AREA SHOW STRONG MID-LEVEL FRONTOGENESIS AND A VERY
DEEP LAYER /AROUND 200 MB/ OF NEGATIVE EPV AND SLIGHTLY
DECREASING THETA-E...INDICATING CONVECTIVE INSTABILITY PRESENT.
THE RUC FORECAST FOR THE FORCING AND INSTABILITY...AND HRRR
PROJECTION OF REFLECTIVITY...SEEMS TO HAVE A STRONG HANDLE ON
THIS...WHILE MOST OTHER GUIDANCE DOES NOT. THIS AREA IS FORECAST
BY THE RUC/HRRR TO COME ACROSS THE SOUTHERN HALF OF THE FORECAST
AREA EARLY THIS MORNING. THE CONVECTIVE SIGNAL WEAKENS
SOMEWHAT...BUT STILL THINK ISOLATED TO SCATTERED THUNDER SHOULD BE
SEEN AT LEAST CLOSE IF NOT INTO THE SOUTHERN FORECAST AREA. THERE
COULD BE SOME SMALL HAIL WITH THIS GIVEN THE LOW WET BULB ZERO
VALUES. THIS SHOULD EXIT BY 10 AM TO NOON...WITH LINGERING CLOUDS
BEHIND THE FRONT ACROSS THE SOUTHERN AREA INTO EARLY TO MID
AFTERNOON.
COLD AIR ADVECTION BEHIND THE FRONT WILL UNDERCUT THE MORNING
CLOUDS AND SHOWERS IN THE SOUTH...HELPING TO KEEP TEMPERATURES
NEARLY STEADY OR EVEN CONTINUING TO FALL THROUGH MID-MORNING.
CLEARING BY LATE MORNING INTO AFTERNOON WILL ALLOW FOR SOME
REBOUND...BUT PROBABLY ONLY INTO THE LOWER TO MID 40S. CONFIDENCE
ON THE DEGREE OF RECOVERY IS SOMEWHAT LOW DUE TO WEIGHING THE COLD
AIR ADVECTION/CLOUD IMPACT THIS MORNING.
THE UPPER TROUGH OVER MN EARLY THIS MORNING WILL PASS OVER THE
GREAT LAKES AND BE RE-ENFORCED BY A STRONG JET MAX TO THE
NORTHWEST. THIS WILL HELP TO PUSH A SECONDARY COLD FRONT SOUTH
THROUGH THE AREA LATE THIS EVENING INTO OVERNIGHT. THIS LOOKS TO
REALLY SEND DEW POINTS DOWN AND POTENTIALLY TEMPERATURES FURTHER
TOO. THE COLD POCKET ASSOCIATED WITH THIS SHOULD DEVELOP SOME
STRATOCU TONIGHT ACROSS NORTHERN AND EASTERN AREAS THAT MAY
POTENTIALLY LINGER INTO FRI MORNING.
HIGH PRESSURE WILL THEN PREVAIL FRIDAY INTO EARLY SATURDAY...WITH
RETURN FLOW THEN SETTING UP FOR SATURDAY...WHICH SHOULD BE A
FAIRLY PLEASANT AND SUNNY DAY. THE WELL-ORGANIZED CLOSED UPPER
LOW OVER THE DESERT SOUTHWEST WILL DRIFT GRADUALLY NORTHEAST ON
SATURDAY...THEN BEGIN TO BECOME MORE NEUTRAL TO NEGATIVELY TILED
AS IT LIFTS OVER OUR AREA ON SUNDAY INTO SUNDAY NIGHT. THE
AMOUNT OF MOISTURE RETURN AHEAD OF THIS IS FAIRLY SHORT IN
DURATION...BUT IT CERTAINLY LOOKS TO BE DEEP ENOUGH AND WITHIN
STRONG ENOUGH ISENTROPIC LIFT FOR FAIRLY WIDESPREAD RAIN/SHOWERS
ON SUNDAY. HAVE CONTINUED TO INCH UP POPS. WHILE THE SYSTEM DRY
SLOT EVOLVES RIGHT INTO THE AREA...ELEVATED INSTABILITY IS VERY
MARGINAL DUE TO THE LIMITED DEGREE OF THETA-E RETURN. SO CONTINUE
WITH NO THUNDER MENTION...BUT COULD SEE SOME GUSTIER SHOWERS
POTENTIALLY SUNDAY AFTERNOON AND EVE IF THE GFS/EC PAN OUT AS IS.
SO HAVE MENTIONED MORE OF A SHOWER WORDING DURING THE AFTERNOON
AND EVE BECAUSE OF THIS. TEMPERATURES ON SUNDAY COULD ENCOMPASS A
FAIRLY LARGE RANGE THANKS TO THE IMPACTS OF THE LIKELY RAIN. WITH
CONFIDENCE INCREASING IN RAIN...HAVE CONTINUED NOT TO INCREASE
TEMPERATURES DESPITE SOME GUIDANCE INDICATING WARMER IN SUCCESSIVE
RUNS.
THE GFS REMAINS CONSISTENT WITH HAVING ANOTHER UPPER
WAVE...ACTUALLY ALMOST A PART OF THE FIRST ONE...MOVE NORTHEAST
ACROSS THE OHIO RIVER VALLEY ON MONDAY NIGHT INTO TUESDAY. THE
08.00 EC TRENDED BACK AWAY FROM THIS...BUT HAS BEEN THE LESS
CONSISTENT MODEL. HAVE KEPT POPS ON TUE MAINLY IN SOUTHEAST AREAS
TO ACCOUNT FOR THIS WAVE. WHILE THIS COULD HAVE IMPACTS ON
TEMPERATURES ON TUE...A LOW-LEVEL THERMAL TONGUE IS PROJECTED TO
BE KNOCKING ON OUR DOOR FROM THE WEST AND SHOULD PROVIDE FOR ABOVE
TO WELL ABOVE NORMAL TEMPERATURES. THE STRONGEST SIGNAL FOR VERY
MILD READINGS AND A DRY ATMOSPHERIC COLUMN IS ON WED AT THIS TIME.
AS PREVIOUS SHIFT DID...LEAN THE FORECAST TOWARDS THE BETTER
PERFORMING EC IN THOSE TYPE OF REGIMES. HIGHS IN THE UPPER 60S
INTO THE 70S ARE CURRENTLY WHAT THIS BLENDED APPROACH PRODUCES
AND SEEMS TO MAKE SENSE. WHILE A FRONT IS PRESENTLY FORECAST TO
MOVE THROUGH SOMETIME LATER WED INTO THU OF NEXT WEEK...IT WOULD
SEEM LIKELY WITH THE PATTERN THAT ABOVE NORMAL TEMPERATURES
CONTINUE THROUGH THE LATTER PART OF NEXT WEEK.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* OCCASIONAL W/NW GUSTS TO 25 KT.
* LOW END MVFR CIGS UNTIL 16Z THEN STEADY IMPROVEMENT TO VFR.
BEACHLER
//DISCUSSION...UPDATED 12Z...
A STRONG COLD FRONT HAS PUSHED EAST OF THE TERMINALS THIS MORNING.
WITH THE FROPA...WINDS HAVE SHIFTED TO NWLY AND DIMINISHED
SOMEWHAT...THOUGH GUSTS TO 25KT ARE LIKELY THROUGH THE DAY. MUCH
OF THE ASSOCIATED PCPN HAS ENDED...BUT AN UPPER LEVEL IMPULSE
MOVING THROUGH CNTRL IL HAS BROUGHT MORE RAIN AND SOME ISOLD
THUNDER...BUT LATEST RADAR IMAGERY INDICATES A WEAKENING TREND AND
IT IS LIKELY THAT ANY REMAINING PRECIP SHOULD REMAIN SOUTH OF THE
TERMINALS...WITH THE POSSIBLE EXCEPTION OF KGYY WHICH MAY STILL
GET CLIPPED WITH SOME SHRA. OTHERWISE...THE TREND FOR THE DAY
SHOULD BE FOR IMPROVING CIGS AS COOLER...DRIER AIR FILTERS IN
BEHIND THE COLD FRONT. EXPECT THAT CIGS SHOULD IMPROVE TO VFR BY
LATE MORNING. THE REMAINDER OF THE PERIOD SHOULD SEE VFR
CONDITIONS AS HIGH PRESSURE BUILDS ACROSS THE REGION. A WEAK LOW
PRESSURE SYSTEM MOVING THROUGH THE UPPER GREAT LAKES TONIGHT
SHOULD DRAG A SECONDARY COLD FRONT ACROSS THE AREA...BRINGING A
REINFORCING SHOT OF COLD AIR. THIS COLD ADVECTION SHOULD BRING
ANOTHER ROUND OF GUSTINESS DURG THE OVERNIGHT HOURS...THOUGH DO
NOT EXPECT GUSTS TO EXCEED 25KT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN WIND DIR/SPEED FORECAST.
* MEDIUM CONFIDENCE IN TIMING OF CIGS IMPROVEMENT.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT AND SATURDAY...VFR.
SUNDAY AND MONDAY...CHANCE OF RAIN. MVFR POSSIBLE.
TUESDAY...CHANCE OF RAIN AND MVFR EARLY...OTHERWISE VFR.
WEDNESDAY...VFR.
KREIN
&&
.MARINE...
325 AM CST
SOUTHWEST GALES ARE FINALLY COMING TO AN END OVER THE LAKE! THE
COLD FRONT IS ALMOST THROUGH LAKE MICHIGAN...WITH THE
SOUTHEASTERN THIRD OF THE LAKE STILL AWAITING ITS ARRIVAL. WINDS
BEHIND THE COLD FRONT HAVE DIMINISHED AND TURNED WEST TO
NORTHWEST. THE ABRUPT CHANGE IN WIND SPEED AND DIRECTION HAS
HELPED WAVES QUICKLY DIMINISH IN THE NEAR SHORE ZONES...THEREFORE
NOT ISSUING A SMALL CRAFT ADVISORY FOR THIS MORNING. WINDS MAY
GUST TO 25 KT FOR THE NEXT COUPLE OF HOURS...BUT NOT LONG ENOUGH
TO WARRANT A SMALL CRAFT ADVISORY.
A WEAKENING LOW MOVES SOUTH OVER THE EASTERN GREAT LAKES AS THE HIGH
PRESSURE TO OUR WEST MOVES INTO SOUTHERN MINNESOTA. AS THE TWO
SYSTEMS MOVE CLOSER TOGETHER THE PRESSURE GRADIENT TIGHTENS
OVERHEAD. THAT COMBINED WITH STRONG PRESSURE RISES WILL CREATE
NORTHWEST GALES OVER THE NORTHERN TWO THIRDS OF THE LAKE LATE
TONIGHT. GALES WILL BEGIN TO DIMINISH FRIDAY MORNING AS THE HIGH
PRESSURE MOVES INTO THE IMMEDIATE AREA. THE HIGH WILL PASS OVER
THE LAKE LATE FRIDAY AFTERNOON INTO FRIDAY EVENING.
YET ANOTHER ROUND OF GALES IS POSSIBLE ON THE BACKSIDE OF THE HIGH
PRESSURE SATURDAY MORNING. LOW END GALES ARE EXPECTED OVER THE
CENTRAL THIRD OF THE LAKE...WITH GALES UP TO 40 KT LIKELY OVER THE
NORTHERN THIRD OF THE LAKE. NOT ANTICIPATING GALES OVER THE
SOUTHERN THIRD OF THE LAKE. GALES BEGIN TO DIMINISH SATURDAY
AFTERNOON AS THE HIGH PRESSURE PULLS AWAY TO THE EAST...HOWEVER
GALES OVER THE NORTHERN END OF THE LAKE LOOK LIKE THEY WILL PERSIST
INTO THE EVENING HOURS.
MODELS HAVE SIGNIFICANT DISCREPANCIES IN TIMING AND THE OVERALL
PATTERN FOR THE REMAINDER OF THE FORECAST...SO WHILE NO GALES ARE
FORECAST FOR NEXT WEEK...FORECAST CONFIDENCE IS LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...3 AM FRIDAY TO 9
PM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1213 PM EST THU MAR 8 2012
.AVIATION... / 18Z TAFS /
POST-FRONTAL RESIDUAL LOW LEVEL MOISTURE WILL CONTINUE TO SUPPORT
MVFR CIGS THROUGH 20/21Z. DRY SUBSIDENT AIR WILL ADVECT IN FROM
THE WEST THIS AFTERNOON WHICH WILL LIKELY SCOUR OUT THIS MVFR
CEILING LEAVING MAINLY CLEAR/VFR SKIES BY LATER THIS AFTERNOON AND
EVENING. PARTIAL CLEARING AND RESULTING DEEPER MIXING WILL ALLOW
WINDS TO PICK UP BY MID AFTN...WITH GUSTS OF 25-30 KNOTS POSSIBLE
THROUGH APPX 00Z. A SECONDARY FRONTAL BOUNDARY WILL DROP THROUGH
THE AREA LATER TONIGHT. LOW LEVEL CAA AND NORTHWESTERLY
TRAJECTORIES BEHIND THIS FRONT WILL ALLOW A LAKE EFFECT STRATO CU
DECK TO SET UP OVER THE TERMINALS TOMORROW MORNING. ATTM...MODEL
FCST SOUNDINGS ARE HINTING AT LOW VFR CEILINGS BTW 3-5 KFT.
&&
.PREV DISCUSSION... /ISSUED 640 AM EST THU MAR 8 2012/
SHORT TERM...
STRONG COLD FRONT WAS JUST COMING INTO FAR NW CWA AT 09Z AND WILL
QUICKLY MOVE ACROSS THE AREA TODAY. RADAR SHOWING AREA OF LIGHT TO
MODERATE SHOWERS ALONG AND BEHIND FRONT WITH SCATTERED SHOWERS OUT
AHEAD OF IT. SURFACE OBS SHOWING A GOOD 10 TO 15 DEGREE TEMP DROP
BEHIND FRONT WITH COLD AIR ADVECTION EXPECTED TO CONTINUE THROUGH
THE DAY WITH LITTLE RECOVERY IN TEMPS EXPECTED. HAVE TRIED TO TIME
FRONT THROUGH THE AREA WITH TEMPERATURE DROP AND PCPN TRENDS. VERY
DIFFICULT TO SAY THE LEAST AND ADJUSTMENTS WILL BE NECESSARY THROUGH
THE MORNING. REGIONAL RADAR MOSAIC AND SATELLITE ALSO SHOWING AN
AREA OF CONVECTION THAT HAS DEVELOPED OVERNIGHT IN OK AND KS AND IS
MOVING NORTHEAST. HRRR SEEMS TO BE ONLY MODEL TO HAVE A DECENT
HANDLE ON THIS WITH 04Z AND 05Z MODEL RUNS HAVING THIS WAVE COMING
INTO NW INDIANA AROUND 14Z. DISCUSSION WITH HPC SUGGEST 06Z RUN
TRENDING FARTHER EAST BUT GIVEN LOOKS OF RESPONSIBLE SHORT WAVE ON
WATER VAPOR AND RECENT RADAR MOSAIC TRENDS HAVE CONCERNS THAT THIS
MAY MOVE BACK INTO PART OF CENTRAL OR WEST CENTRAL CWA BY MID
MORNING. FOR THIS REASON HAVE SLOWED THE TREND OF CLEARING POPS
ACROSS THE AREA BY ABOUT 3 TO 5 HOURS TO ACCOUNT FOR THE POSSIBILITY
OF THIS RAIN MOVING BACK IN. BY AFTERNOON THIS WAVE LOOKS TO CLEAR
THE AREA AND RAPID DRYING BEGINS AND SHOULD SEE CLEARING SKIES.
ANOTHER FAST MOVING SHORT WAVE PASSES TO THE NORTH TONIGHT BUT
DRIVES SECONDARY COLD FRONT THROUGH. MAY SEE SOME INCREASE IN CLOUDS
NORTH WITH THIS WAVE AND LAKE PLUME AS DELTA T VALUES CLIMB INTO THE
TEENS. REMAINDER OF SHORT TERM FORECAST DRY WITH HIGH PRESSURE
MOVING IN FRIDAY NIGHT. THIS SHOULD ALLOW WINDS TO DECOUPLE AND
EXPECT GOOD RADIATIONAL COOLING BEFORE RETURN FLOW TRIES TO DEVELOP
LATE. HAVE LOWERED TEMPS FRIDAY NIGHT.
LONG TERM...
SATURDAY THROUGH WEDNESDAY...A LONG WAVE TROF WILL BECOME ENTRENCHED
ALONG THE WESTERN NORTH AMERICAN COAST WITH LARGE SCALE
AMPLIFICATION DOWNSTREAM OVER THE CENTRAL AND EASTERN CONUS. MUCH
WARMER AIR WILL RETURN TO THE AREA AND PERSIST THROUGH NEXT WEEK.
SHORT WAVE ENERGY WILL EJECT NORTHEAST AND PROVIDE A CHANCE FOR
SHOWERS THROUGH MOST OF THE PERIOD AS GULF MOISTURE SPREADS NORTH
ACROSS THE OHIO RIVER. THE GFS ENSEMBLE MEMBERS HAVE FINALLY COME
INTO REASONABLE AGREEMENT WITH ONE ANOTHER WITH MUCH SMALLER
STANDARD DEVIATIONS REFLECTED IN THE MEX MOS. THERE IS POTENTIAL
FOR HIGHS TO TOP 70 DEGREES DURING THE LATTER HALF OF THIS PERIOD.
HOWEVER...GIVEN THE POTENTIAL FOR CLOUDS AND RAINFALL...KEPT HIGHS
IN THE MID TO UPPER 60S TUESDAY/WEDNESDAY. ALSO...THERE IS AN
OUTSIDE CHANCE ONE OF THE SHORTWAVES MAY BE ABLE TO TAP A LITTLE
COOLER AIR AFTER THE SHORT WAVE PASSES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM EST FRIDAY FOR LMZ043-046.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...STEINWEDEL
AREA FORECAST DISCUSSION...CORRECTED AVIATION DISCUSSION
NWS QUAD CITIES IA IL
310 PM CST THU MAR 8 2012
.SYNOPSIS...
12Z UA ANALYSIS HAS AN 850MB COLD FRONT FROM SOUTHERN LAKE HURON INTO
SOUTHEAST NEW MEXICO. A BIT MORE IMPRESSIVE IS THE 700MB COLD FRONT
FROM THE MACKINAC STRAITS INTO SOUTHEAST COLORADO. A STRONG LLJ WAS
TRANSPORTING MOISTURE FROM THE GULF COAST INTO NEW ENGLAND. SATELLITE
TRENDS HAVE MID AND HIGH LEVEL CLOUDS FROM THE CENTRAL PLAINS INTO
THE OHIO VALLEY. LOW LEVEL SC/CU WERE ACROSS THE UPPER MIDWEST IN
ASSOCIATION WITH A SHORTWAVE ROTATING ACROSS NORTHERN IOWA TOWARD
WISCONSIN.
18Z SFC ANALYSIS HAS THE PRIMARY FRONT FROM TEXAS INTO THE OHIO
VALLEY WITH SEVERAL WEAK TROFS FROM THE GREAT LAKES INTO THE NORTHERN
PLAINS. A NEW COLD FRONT WAS DROPPING SOUTH FROM CANADA AND WAS INTO
NORTH DAKOTA AND MINNESOTA. DEW POINTS WERE IN THE TEENS AND 20S
ACROSS MUCH OF THE MIDWEST WHILE 40S AND GREATER DEW POINTS RAN FROM
THE SOUTHERN PLAINS INTO THE OHIO VALLEY.
&&
.SHORT TERM...TONIGHT AND FRIDAY...
THE SHORTWAVE AND ASSOCIATED PV ANOMALY IS MOVING INTO SOUTHERN
WISCONSIN. THESE FEATURES COMBINED WITH STEEP LOW LEVEL LAPSE RATES
HELPED PRODUCE THE STRONG WINDS STARTING AROUND MID DAY. AS THE
BOUNDARY LAYER STABILIZES WITH SUNSET THE WINDS WILL DECREASE.
LATER TONIGHT A STORM SYSTEM WILL PASS NORTH OF THE AREA BUT WILL
DRAG ANOTHER COLD FRONT/BOUNDARY THROUGH THE AREA. THUS CLOUDS WILL
BE ON THE INCREASE LATER THIS EVENING. ONCE THE FRONT PASSES...
STRONG SUBSIDENCE SHOULD START BREAKING UP THE CLOUDS PRIOR TO
SUNRISE. THE RUC DOES INDICATE LOW LEVEL LAPSE RATES GETTING STEEPER
LATE TONIGHT SO THE SUBSIDENCE SHOULD ALLOW WINDS TO PICK UP AGAIN
BEFORE DECREASING AGAIN PRIOR TO SUNRISE.
ON FRIDAY HIGH PRESSURE SETTLES ACROSS THE AREA RESULTING IN MUCH
LIGHTER WINDS AND GENERALLY SUNNY SKIES. SUBSIDENCE WILL LIMIT THE
AMOUNT OF MIXING THAT OCCURS BUT THE STRONG MARCH SUN SHOULD ALLOW
TEMPERATURES TO BE SIMILAR TO THURSDAY. ..08..
.LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY...
CONTINUED ABOVE NORMAL TO WELL ABOVE NORMAL WITH A LIGHT TO MODERATE
RAIN EVENT LATE SUNDAY INTO MONDAY.
OVERALL...INITIALIZATION AND VERIFICATION SLIGHTLY BELOW AVERAGE WITH
SIGNFICANT DISCREPANCIES OF TEXAS CONVECTION. THIS WILL IMPACT THE
TIMING...EVOLUTION AND TRACK OF UPPER LOW FOR LATE SUNDAY. THIS IS
HANDLED ADEQUATELY BY A BLEND OF THE HI-RES ECMWF AND GFS BUT COLD
FRONTAL EVOLUTION SUGGESTS A BIT FASTER TRACK AND QUICKER OCCLUSION
THAT MAY BECOMEM EVIDENT THE NEXT 24 HOURS WITH FASTER STARTING OF
RAIN ON SUNDAY AND IN NW SECTIONS...LIGHTER AMOUNTS OF PRECIPITION.
FRIDAY NIGHT...TRIMMED LOWS A FEW DEGREES IN EASTERN SECTIONS DUE TO
LIGHT SE WINDS ALLOWING FOR A BIT OF DECOUPLE UNDER A CLEAR SKY WITH
MIDDLE 20S POSSIBLE FOR LATER SHIFTS AND A DECENTR FROST ALONGAND
EAST OF THE MISSISSIPPI RIVER.
SATURDAY...WARMING TREND WITH INCREASING SOUTH TO SOUTHWEST WINDS AND
COPIOUS SUNSHINE. UPPED HIGHS TO AROUND 60F WESTERN SECTIONS AND
MIDDLE 50S EAST. IF ENOUGH BL MIXING OCCURS AS SUGGESTED...MAX TEMPS
MAY STILL BE A FEW DEGREES TOO COOL. MINS SATURDAY NIGHT MAY BE
AROUND MIDNIGHT BEFORE HIGH CLOUDS ARRIVE WITH UPPER 30S NORTH AND
LOWER TO POSSIBLY MIDDLE 40S SOUTH SECTIONS.
SUNDAY...AREAS OF LIGHT TO MODERATE RAIN TO OVERSPREAD THE AREA WITH
AMOUNTS MOSTLY A QUARTER TO LOCALLY AROUND A HALF INCH. CLOUDS AND
EVAPORATIVE COOLING TO KEEP HIGHS IN THE 50S THAT MAY FALL INTO THE
40S WITH PERIODS OF RAIN. TIMING QUESTION PRECLUDES GOING MORE THAN
LIKELY WITH BULK OF RAIN SUGGESTED BETWEEN 21-09Z ATTM. SUNDAY NIGHT
MINS MILD MOSTLY IN THE MIDDLE 40S DUE TO HIGH DEWPOINTS AND RH
VALUES WITH LIGHT FOG NOT OUT OF THE QUESTION FOR LATER SHIFTS.
MONDAY...CLEARING SKIES WITH ANY RAIN ENDING EARLY. SOUTH WINDS TO
USHER IN MILD GULF OF MEXICO AIR WITH HIGHS WELL INTO THE 60S...OR
ABOUT 20 DEGREES ABOVE NORMAL.
TUESDAY THROUGH THURSDAY...MILD AND DRY WITH MORE WELL ABOVE NORMAL
TEMPERATURES. HIGHS 65-75F SUGGESTED WITH LOWS 45-55 DEGREES WITH
LIGHT TO MODERATE WINDS. WITH ENOUGH BL MIXING...UPPER 70S MAXES
SUGGESTED WHICH ARE RECORD HIGHS FOR THIS PERIOD. RECORD MILD MINS
ARE AROUND 50 DEGREES WHICH MAY ALSO BE THREATENED. ..NICHOLS..
&&
.AVIATION...
VFR WX IS EXPECTED THROUGH 12Z/10. SUNSET WILL ALLOW THE ATMOSPHERE
TO STABILIZE AND ALLOW WINDS TO DIMINISH. ANOTHER FRONTAL BOUNDARY
IN THE NORTHERN PLAINS WILL MOVE THROUGH IOWA AND ILLINOIS IN THE
03Z-09Z/09 TIME FRAME BUT WILL COME THROUGH DRY BUT WINDS ARE
EXPECTED TO INCREASE AFTER FRONTAL PASSAGE. HIGH PRESSURE BUILDING
INTO THE MIDWEST PRIOR TO SUNRISE AND FRIDAY WILL ALLOW WINDS TO
AGAIN DIMINISH.
..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
08/NICHOLS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1235 PM CST THU MAR 8 2012
.UPDATE...
DEEP MIXING IS UNDERWAY WITH HIGHER MOMENTUM AIR MIXING DOWN TO
THE SFC. RUC TRENDS INDICATE LOW LEVEL LAPSE RATES MAY APPROACH
DRY ADIABATIC THIS AFTERNOON.
THE APPROACHING SHORTWAVE HAS A STRONG PV ANOMALY ASSOCIATED WITH
IT WHICH IS AIDING IN MIXING DOWN THE HIGHER MOMENTUM AIR. PER THE
RUC THE PV ANOMALY SHOULD PASS JUST NORTH OF THE CWFA BUT THE
TIGHT PV GRADIENT ON THE SOUTH SIDE WILL MOVE ACROSS THE NORTHERN
CWFA PRODUCING THE STRONG WINDS.
BASED ON MOVEMENT FROM WATER VAPOR...THE SHORTWAVE AND PV ANOMALY
SHOULD BE ACROSS SOUTHEAST WISCONSIN BY SUNSET. AT THAT TIME LAPSE
RATES WILL BEGIN TO STABILIZE AND WINDS SHOULD DIMINISH QUICKLY.
..08..
&&
.PREV DISCUSSION... /ISSUED 1046 AM CST THU MAR 8 2012/
UPDATE...
DATA THROUGH 15Z HAS HIGH LEVEL CLOUDS ACROSS THE SOUTHERN PART OF
THE CWFA WHICH IS ASSOCIATED WITH TWO SFC WAVES MOVING ALONG THE
COLD FRONT IN ARKANSAS. WATER VAPOR HAS A NICE VORT MAX AND
ASSOCIATED SHORT WAVE ROTATING SOUTHEAST INTO NORTHERN IOWA IN THE
FLOW ALOFT. THERE ARE SOME SC/CU CLOUDS ASSOCIATED WITH THIS VORT
MAX AND VISIBLE TRENDS THE PAST FEW HOURS SUGGEST A POTENTIAL FOR
THOSE CLOUDS TO MOVE INTO THE NORTHERN CWFA.
LOW LEVEL LAPSE RATES ARE STEEPENING FROM THE DIURNAL HEATING
WHICH IS ALLOWING HIGHER MOMENTUM AIR ALOFT TO MIX DOWN. RUC
TRENDS SUGGEST SUSTAINED WINDS SHOULD INCREASE A BIT MORE FROM
LATE MORNING THROUGH MID AFTERNOON BUT NOT BY MUCH. HOWEVER...WIND
GUSTS SHOULD INCREASE A BIT MORE AS THE SHORTWAVE MOVES THROUGH
THE AREA. IF THE RUC TIMING IS CORRECT...SOME GUSTS TO 40 MPH MAY
BE POSSIBLE DURING THE AFTERNOON IN THE NORTHEAST QUADRANT OF THE
CWFA.
.08..
AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH 00Z/10 AS HIGH PRESSURE SLOWLY
BUILDS INTO THE MIDWEST. DAYTIME HEATING IS ALLOWING STRONGER
WINDS ALOFT TO MIX DOWN AND A PASSING DISTURBANCE ALOFT MAY ALLOW
A BRIEF PERIOD OF WIND GUSTS OF 30-35KTS A FEW HOURS EITHER SIDE
OF 21Z/08. THE DAYTIME HEATING MAY ALSO ALLOW SOME DIURNAL CU/SC
TO DEVELOP BUT ANY CIGS WILL BE ABV 3KFT AGL. AS HIGH PRESSURE
SETTLES OVER THE AREA LATE TONIGHT WINDS WILL DIMINISH.
.08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1046 AM CST THU MAR 8 2012
.UPDATE...
DATA THROUGH 15Z HAS HIGH LEVEL CLOUDS ACROSS THE SOUTHERN PART OF
THE CWFA WHICH IS ASSOCIATED WITH TWO SFC WAVES MOVING ALONG THE
COLD FRONT IN ARKANSAS. WATER VAPOR HAS A NICE VORT MAX AND
ASSOCIATED SHORT WAVE ROTATING SOUTHEAST INTO NORTHERN IOWA IN THE
FLOW ALOFT. THERE ARE SOME SC/CU CLOUDS ASSOCIATED WITH THIS VORT
MAX AND VISIBLE TRENDS THE PAST FEW HOURS SUGGEST A POTENTIAL FOR
THOSE CLOUDS TO MOVE INTO THE NORTHERN CWFA.
LOW LEVEL LAPSE RATES ARE STEEPENING FROM THE DIURNAL HEATING
WHICH IS ALLOWING HIGHER MOMENTUM AIR ALOFT TO MIX DOWN. RUC
TRENDS SUGGEST SUSTAINED WINDS SHOULD INCREASE A BIT MORE FROM
LATE MORNING THROUGH MID AFTERNOON BUT NOT BY MUCH. HOWEVER...WIND
GUSTS SHOULD INCREASE A BIT MORE AS THE SHORTWAVE MOVES THROUGH
THE AREA. IF THE RUC TIMING IS CORRECT...SOME GUSTS TO 40 MPH MAY
BE POSSIBLE DURING THE AFTERNOON IN THE NORTHEAST QUADRANT OF THE
CWFA.
..08..
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH 00Z/10 AS HIGH PRESSURE SLOWLY
BUILDS INTO THE MIDWEST. DAYTIME HEATING IS ALLOWING STRONGER
WINDS ALOFT TO MIX DOWN AND A PASSING DISTURBANCE ALOFT MAY ALLOW
A BRIEF PERIOD OF WIND GUSTS OF 30-35KTS A FEW HOURS EITHER SIDE
OF 21Z/08. THE DAYTIME HEATING MAY ALSO ALLOW SOME DIURNAL CU/SC
TO DEVELOP BUT ANY CIGS WILL BE ABV 3KFT AGL. AS HIGH PRESSURE
SETTLES OVER THE AREA LATE TONIGHT WINDS WILL DIMINISH.
..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1245 PM MST THU MAR 8 2012
.UPDATE...
ISSUED AT 522 AM MST THU MAR 8 2012
STARTING TO SEE 12Z RAOBS COME IN AND AS EXPECTED AIR MASS BUILDING
IN FROM THE NORTH LOOKS MUCH DRIER THAN PREVIOUS DAY. ESTIMATED
MIXED LAYER DEWPOINTS OFF OF KLBF SOUNDING WOULD SUPPORT SINGLE
DIGIT DEWPOINTS WITH ANY DEEP MIXING. GOES SOUNDINGS ALSO
SUPPORTING VERY DRY LAYER ALOFT...AND THINK WITH PLENTIFUL
SUNSHINE MUCH OF THE AREA WILL TAP INTO THIS DRIER AIR THIS
AFTERNOON. DROPPING TDS INTO SINGLE DIGITS ALONG THE LINES OF
LATEST HRRR STILL KEEP AFTERNOON HUMIDITY VALUES JUST ABOVE
CRITICAL VALUES. WITH STRONGEST WINDS LIKELY BEFORE 20Z...THE
MARGINAL NATURE OF PARAMETERS AND UNCERTAINTY IF WINDS/RH WILL
LINE UP FOR SEVERAL HOURS KEEPS CONFIDENCE TOO LOW TO ISSUE A RFW
AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 155 AM MST THU MAR 8 2012
TODAY...AREA OF THUNDERSTORMS THAT DEVELOPED ALONG NOSE OF STRONG
ISENTROPIC ASCENT SHOULD CONTINUE TO DIMINISH/SHIFT SOUTH OF THE
AREA THROUGH THE MORNING HOURS AS COLD AND DRY AIR ADVECTION
OVERSPREAD THE AREA BEHIND DEPARTING TROUGH MOVING ACROSS EASTERN
NEBRASKA. WITH MUCH DRIER AIR MOVING INTO THE AREA AND FAIRLY DEEP
DOWNWARD MOTION...DO NOT SEE MUCH IN THE WAY OF A PRECIPITATION THREAT
ONCE OVERNIGHT CONVECTION BEGINS TO SHIFT SOUTH. SKIES WILL
GRADUALLY CLEAR...ALTHOUGH PLACEMENT OF CUT OF LOW AND PERSISTENT
DEFORMATION ZONE MAY PROMOTE A PERSISTENT AREA OF MID/HIGH CLOUDS
ACROSS SOUTHERN CWA...BUT AM NOT EXPECTING MUCH OF AN IMPACT ON
SENSIBLE WX AT THIS TIME. TEMPERATURES SHOULD REBOUND INTO THE LOWER
50S ACROSS MUCH OF THE AREA DESPITE THE CAA WITH GUSTY NORTHERLY
WINDS EXPECTED BTWN 15 AND 20Z BEFORE THINGS BEGIN TO DIMINISH. WITH
LOW TEENS/SINGLE DIGIT DEWPOINTS MOVING INTO THE AREA...EXPECT
HUMIDITIES TO FALL TO AROUND 20 PERCENT RANGE AND WITH THE GUSTY
WINDS MAY APPROACH CRITICAL FIRE WX CONDITIONS FOR AN HOUR OR SO.
CURRENTLY HUMIDITIES LOOK TO BE ABOVE CRITERIA AND WINDS ARE
EXPECTED TO DIMINISH WHILE HUMIDITIES ARE AT THEIR LOWEST VALUES.
HAVE SEEN A FEW POST FRONTAL FIRE WEATHER EVENTS THOUGH WITH DEEP
COLD AND DRY AIR ADVECTION AND MAY NEED TO REEVALUATE ONCE 12Z RAOBS
ARE AVAILABLE.
TONIGHT-FRIDAY...GENERAL CONSENSUS IS UPPER LOW WILL MOVE INTO THE TEXAS
PANHANDLE...WELL REMOVED FROM THE FORECAST AREA...WITH GEM AND SREF
MEAN CONTINUING TO INDICATE SOME RETROGRADE MOTION. BOTH OF THESE
SOLUTIONS AND GENERAL MODEL CONSENSUS KEEPS CWA WELL TO THE NORTH OF
ANY APPRECIABLE PRECIPITATION THREAT AS STABLE MID LEVELS...AND
PERSISTENT DRY NORTHERLY FLOW OVERNIGHT THURSDAY WILL BE ENOUGH TO
PREVENT PRECIP DEVELOPMENT...EVEN IF SOME LARGE SCALE FORCING FOR
ASCENT MAY BE PRESENT. MID LEVEL FLOW EXPECTED TO BECOME A BIT MORE
SOUTHERLY DURING THE DAY ALLOWING FOR SOME INCREASING CLOUDS...BUT
WITH BULK OF LARGE SCALE FORCING FOR ASCENT TO THE SOUTH OF THE AREA
AND OVERALL LOW CONFIDENCE IN LARGE SCALE FEATURES...THINK DRY
CONDITIONS WILL PREVAIL.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 155 AM MST THU MAR 8 2012
FRIDAY NIGHT-SATURDAY NIGHT...WHILE NEAR TERM MODELS HAVE COME INTO A
LITTLE BETTER AGREEMENT WITH HOW H5 TROUGH WILL GRADUALLY LIFT TO
THE NORTH ACROSS THE AREA THROUGH THE PERIOD...THERE REMAINS
CONSIDERABLE SPREAD WITH RESPECT TO THE TIMING DIFFERENCES GREATER
THAN 12 HOURS NOTED IN THE GEFS SPAGHETTI PLOTS FOR THE PERIOD.
GIVEN THE FAIRLY COLD TEMPS ALOFT LEADING TO SOME DESTABILIZATION
AND PV ADVECTION...THINK THERE IS AT LEAST A SMALL THREAT FOR
PRECIPITATION AS IT PASSES. HOWEVER WITH AFOREMENTIONED UNCERTAINTY
WITH RESPECT TO TIMING...CAN NOT REALLY JUSTIFY ANY MORE THAN SLIGHT
PROBABILITIES AT THIS POINT FOR SATURDAY AND SATURDAY
NIGHT...ALTHOUGH SLIGHTLY PREFER A SLOWER SOLUTION WHICH WOULD
IMPACT AREA MORE ON SATURDAY NIGHT. -JRM
SUNDAY THROUGH WEDNESDAY...MODELS ARE CONTINUING TO COME INTO
BETTER AGREEMENT WITH TRACK OF THE UPPER LEVEL CLOSED FOR THIS
PERIOD. CURRENT GUIDANCE HAS THE CLOSED LOW MOVING OVER THE AREA
SUNDAY. PLACED IN SLIGHT CHANCES FOR THE EASTERN PART OF THE AREA
WHERE ISENTROPIC LIFT AND 5-7H FRONTOGENESIS DEVELOP AHEAD OF THE
CLOSED LOW AS IT MOVES THROUGH. AN UPPER LEVEL TROUGH JUST BEHIND
THE CLOSED LOW WILL ALSO LIFT NORTHEAST SUNDAY NIGHT INTO
MONDAY...BUT WILL REMAIN WELL SOUTH OF THE AREA. MONDAY A SHORT
WAVE RIDGE MOVES IN BEHIND THE CLOSED LOW. TUESDAY AND WEDNESDAY
THE UPPER LEVEL FLOW TURNS TO THE SOUTHWEST...BRINGING DRY AIR
OVER THE AREA WHILE A SHORTWAVE TROUGH MOVES ACROSS THE NORTHWEST
CONUS.
TEMPERATURES FOR THE PERIOD WILL BE ABOVE NORMAL...WITH HIGHS AROUND
70 AND LOWS AROUND 40 BY THE START OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 21Z TAFS THROUGH 21Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM MST THU MAR 8 2012
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. NORTHERLY WINDS WILL
CONTINUE TO GRADUALLY DIMINISH THROUGH SUNSET. A FEW HIGH CLOUDS
ARE SPILLING NORTH FROM A SYSTEM IN THE FOUR CORNERS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...JRM
LONG TERM....JRM/JTL
AVIATION...024
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1233 PM EST THU MAR 8 2012
.SYNOPSIS...
ISSUED AT 537 AM EST THU MAR 8 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH AXIS
FROM NW ONTARIO THROUGH WRN MN INTO ERN NEBRASKA. A BAND OF LIGHT
SNOW MOVING QUICKLY THROUGH THE ERN CWA WAS SUPPORTED BY 700-600 MB
FGEN BEHIND THE COLD FRONT THAT EXITED UPPER MI TO THE SE.
OTHERWISE...JUST A FEW FLURRIES REMAINED OVER CNTRL UPPER MI. AN
UPSTREAM SHRTWV WAS MOVING FROM SE SASK TOWARD SRN MANITOBA. AT THE
SFC..NW WINDS PREVAILED BTWN A TROUGH FROM QUEBEC TO LAKE HURON AND
A RIDGFROM THE NRN PLAINS INTO NW ONTARIO. THE CLIPPER LOW
ASSOCIATED WITH THE CLIPPER SHRTWVWAS LOCATED OVER N CNTRL MANTIOBA
WITH A TRAILING COLD FRONT TO THE SW.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 537 AM EST THU MAR 8 2012
TODAY...EXPECT THE MID LEVEL TROUGH MOVING INTO THE AREA BY
AFTERNOON TO BE REINFORCED BY THE SASK SHRTWV BY LATE TODAY. THE
COMBINATION OF INCREASING 700-500 MB QVECTOR CONV...DEEPER
MOISTURE...DAYTIME HEATING AND STEEP 900-700 MB LAPSE RATES NEAR 8
C/KM WILL SUPPORT SCT SHSN DEVELOPMENT THIS AFTERNOON WHICH WILL
INCREASE IN COVERAGE AND INTENSITY LATE.
TONIGHT...SHSN WILL TRANSITION TO LES AS COLDER AIR ARRIVES
(850 MB TEMPS ARE FCST TO DROP INTO THE -14C TO -18C RANGE) AND WINDS
VEER TO THE NW. AS THE WINDS VEER THE STRONGER LOW LEVEL CONV WILL
SHIFT FROM WRN UPPER MI INTO THE NE CWA E OF MARQUETTE. WITH
FAVORABLE 850-700 MB MOISTURE AND INVERSION HEIGHTS TO NEAR 10K
FT...SOME STRONGER SNOWBANDS MAY DEVELOP WITH BRIEF HEAVY SNOW.
HOWEVER...GIVEN THE SHIFTING LOCATION OF THE BANDS...OVERALL
ACCUMULATIONS SHOULD STILL REMAIN IN THE 1 TO 3 INCH RANGE. WITH THE
LONGER FETCH INTO THE EAST...SOME ISOLATED HIGHER AMOUNTS TO AROUND 4
INCHES MAY BE POSSIBLE NEAR OR JUST INLAND FROM GRAND MARAIS. GUSTY
NORTHWEST WINDS INTO THE 20 TO 30 MPH RANGE NEAR LAKE SUPERIOR WILL
ALSO CAUSE AREA OF BLSN.
FRIDAY...LES WILL DIMINISH FROM THE WEST AS DRIER AIR MOVES INTO THE
REGION ALONG WITH ACYC FLOW AND LOWERING INVERSION HEIGHTS AND (AOB
4K FT). HOWEVER...ADDITIONAL AMOUNTS IN THE 1 TO 3 INCH RANGE MAY BE
POSSIBLE OVER THE EAST AS THE 850 MB THERMAL TROUGH (850 MB TEMPS
AROUND -18C) LINGERS INTO THE EARLY AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 537 AM EST THU MAR 8 2012
...RAIN FOLLOWED BY SIGNIFICANT WARM-UP EARLY-MID NEXT WEEK MAY
RESULT IN HYDRO ISSUES...
NOTE: SEE LATER PORTION OF THIS LONG TERM DISCUSSION FOR THOUGHTS ON
POSSIBLE HYDROLOGY ISSUES.
POP/WX WISE IT IS PRETTY QUIET FRIDAY NIGHT THROUGH SATURDAY NIGHT.
WARM AIR ADVECTIONS RAMPING UP AGAIN COULD LEAD TO BATCH OF LGT SNOW
OVR LK SUPERIOR AND PERHAPS THE FAR NORTHERN FRINGE OF THE CWA.
OTHERWISE JUST A PERIOD OF MID CLOUDS. MAIN STORY FRIDAY NIGHT INTO
SATURDAY WILL BE GUSTY SOUTH TO SOUTHWEST WINDS.
TREND THAT BEGAN TO APPEAR IN MODELS YESTERDAY CONTINUES TODAY. AS
HIGH PRESSURE RIDGE MOVES EAST FRIDAY NIGHT SFC TROUGH OVR CNTRL
CANADA WILL STEAMROLL EAST BY SUNRISE SATURDAY. TIGHT PRESSURE
GRADIENT ENSUES AND VERY STRONG PRESSURE FALLS /OVR 12MB IN 6 HR/
ARE FCST NORTH OF LK SUPERIOR. PATTERN SUGGESTS THAT DESPITE WARM
AIR ADVECTION REGIME...SOUTH TO SOUTHWEST WINDS COULD BECOME QUITE
GUSTY. FCST SOUNDINGS INDICATE A LOT OF WIND JUST ABOVE SFC /50+ KTS
AT 925MB PER GFS/ECMWF/NAM/ BUT IT IS STABLE. BLYR WINDS USUALLY DO
A GOOD JOB HIGHLIGHTING HOW STRONG WINDS COULD GET AND THIS OUTPUT
POINTS TO SOLID 35-40 KTS. GALES OVR LK SUPERIOR AND PROBABLY
NEARSHORE ZONES OF LK MICHIGAN GOOD BET. ALSO...GOING TO MENTION
SOME NEAR ADVY GUSTS IN HAZARDOUS WEATHER OUTLOOK FOR SOUTH SHORE OF
LK SUPERIOR. BASED ON SFC WIND DIRECTION AND WHERE CORE OF STRONGEST
WINDS IS FCST...THE SHORELINE FM BARAGA TO MARQUETTE ALONG LK
SUPERIOR WOULD SEE STRONGEST WINDS. ALSO COULD SEE STRONGER WINDS
OVR KEWEENAW COUNTY AS THAT AREA IS EXPOSED TO SOUTHERLY
FLOW...ESPECIALLY HIGHER TERRAIN AREAS. PRESSURE FALL MOVES STEADILY
TO THE EAST THROUGH THE DAY...BUT SOUNDINGS POINT TO BREEZY
CONDITIONS CONTINUING FOR MUCH OF SATURDAY AS MIXING WILL BE HIGHER
DUE TO MAINLY SUNNY SKIES. AS SOUTH WINDS KICK UP LATER FRIDAY NIGHT
TEMPS SHOULD BEGIN TO RISE OVR MUCH OF CWA. USED NON-DIURNAL TEMP
CURVE INTO SATURDAY WITH LOWS FRIDAY EVENING IN THE TEENS AND TEMPS
RISING TOWARD FREEZING BY SUNRISE SATURDAY. MIXING TO H9 ON SATURDAY
SEEMS PRETTY GOOD CONSIDERING AMOUNT OF INSOLATION EXPECTED. MIXING
THIS HIGH GAVE READINGS INTO THE 50S OVR MOST OF THE WEST HALF OF
CWA. SW WINDS WILL KEEP LK MICHIGAN AND INLAND AREAS OF EAST CWA
COOLER IN THE UPR 30S TO MID 40S.
IN THE EXTENDED...COULD BE AN ACTIVE WEATHER PERIOD OVR MUCH OF UPR
LAKES...BUT NOT NECESSARILY FM AMOUNT OF STORM SYSTEMS. RATHER...ONE
SYSTEM LOOKS TO BRING LGT MAYBE MODERATE RAIN AMOUNTS TO AREA LATER
SUNDAY THROUGH SUNDAY NIGHT THEN A VERY SIGNIFICANT WARM-UP IS IN
STILL LOOKS TO BE IN THE OFFING INTO THE MIDDLE OF NEXT WEEK. IF ALL
GOES AS PLANNED...MOST AREAS IN THE CWA BY THIS TIME NEXT WEEK WILL
HAVE LOST A MAJORITY IF NOT ALL OF THE SNOWPACK. WILL BE SOMETHING
TO MONITOR INTO NEXT WEEK AS THERE COULD BE SOME HYDRO ISSUES GIVEN
POTENTIAL TO MELT THE SNOW RATHER QUICKLY. LOW PRESSURE STILL FCST
TO LIFT FM THE PLAINS/MISSISSIPPI RIVER VALLEY INTO THE UPR LAKES
LATE SUNDAY. IN A GENERAL SENSE...THREE MAIN MODELS USED FOR THE
EXTENDED /GFS/ECMWF/CANADIAN/ ALL SHOW THIS SYSTEM IMPACTING UPR MI.
TIMING IS NOT SET THOUGH...AS LATEST ECMWF NOW BRINGS THE LOW MORE
ACROSS LATER SUNDAY NIGHT INTO MONDAY. THIS TIMING IS CLOSER TO
CANADIAN BUT STRAYS SIGNIFICANTLY FM NCEP MODELS /GFS AND NAM/. NCEP
PREFERRED SLOWER APPROACH AS THERE COULD BE SOME BLOCKING AHEAD OF
THE FEATURE. TRENDED THIS WAY IN GRIDS. HIGHEST CHANCES SUNDAY NIGHT
STILL LOOKED FINE. MAIN CHANGE TO CONSENSUS ALLBLEND APPROACH WAS TO
KEEP CHANCE POPS IN FOR ALL DAY MONDAY.
ONCE THE SYSTEM CLEARS THE AREA LATER MONDAY/MONDAY NIGHT...ATTN IS
ON POTENTIAL WARM-UP. SEEMS LIKE MORE OFTEN THAN NOT IN RECENT YEARS
WE HAVE LOST THE SNOWPACK IN THE SPRING WITH MORE OF A GRADUAL WARM
UP IN A STEADY FREEZE-THAW CYCLE /RISING ABOVE FREEZING DURING THE
DAYS BUT FALLING BLO AT NIGHT/. WE SEE HOW WHEN THIS DOES NOT WORK
WHAT CAN HAPPEN AS YESTERDAY AT THE OFFICE IN NEGAUNEE TWP WITH
HIGHS AROUND 50 DEGREES AND DWPNTS WELL INTO THE 40S...WE LOST 8
INCHES OF OUR SNOWPACK IN ONE DAY! AFTER OUR BREAK IN THE SNOWMELT
THE NEXT COUPLE DAYS...SEEMS LIKE WE COULD BE HEADING FOR SIMILAR
QUICK SNOWMELT LATE THIS WEEKEND THROUGH MID NEXT WEEK. MAIN CONCERN
WOULD BE TUESDAY AND WEDNESDAY AS ECMWF /WHICH FOR MOST PART USUALLY
LEADS WAY ON THESE TYPE OF WARM-UPS WELL OVER CLIMATOLOGY/ INDICATES
MAX TEMPS PUSHING OVER 60 DEGREES OVR AT LEAST THE WEST HALF OF THE
CWA. ALLBLEND GUIDANCE /BIASED TOWARD THE GFS/ WAS MUCH COOLER AND
WAS ADJUSTED UPWARD FOR BOTH DAYS. ECMWF ALSO INDICATES DWPNTS
RISING ABOVE 40...ESPECIALLY ON WEDNESDAY AHEAD OF WEAK TROUGH FCST
TO COME THROUGH ON THURSDAY.
A COUPLE OF CAUTIONS THOUGH. LATEST ECMWF NOW TRYING TO SHOW MORE
OF A TYPICAL SPRING LIKE MSLP PATTERN ON TUESDAY WITH POSSIBLE LAKE
BREEZES AS MAIN TROUGH REMAINS OVR PLAINS. TRIMMED TEMPS SLIGHTLY
TOWARD LK SUPERIOR SHORE FOR TUESDAY...WITH BETTER SHOT OF THE
REALLY WARM TEMPS STAYING INLAND TOWARD WI BORDER. TROUGH IS CLOSE
ENOUGH ON WEDNESDAY TO RESULT IN MAINLY SW FLOW FOR ALL AREAS AND
ALLOWING THE WARM TEMPS RIGHT TO PUSH TO THE LK SUPERIOR SHORE AS
WELL ALONG WITH DWPNTS RISING WELL ABOVE 40F. OBVIOUSLY GIVEN THIS
KIND OF MOISTURE ADVECTION AND THE MELING SNOWPACK ONGOING...SOME
STRATUS/FOG IS NOT OUT OF QUESTION WHICH WOULD IMPACT TEMPS. STILL
QUESTIONS IN SPECIFICS BUT THIS TIME FRAME COULD POSE SOME ISSUES
WITH REGARD TO RISES ON RIVES/STREAMS AND SOME AREAL FLOODING
CONCERNS IN LOW-LYING SPOTS AS WELL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1232 PM EST THU MAR 8 2012
AN APPROACHING DISTURBANCE/STEEP LAPSE RATES/DAYTIME HEATING WILL
LIKELY LEAD TO SCT/NMRS -SHSN LATER THIS AFTN INTO THE EVENING HRS.
MVFR CONDITIONS SHOULD GENERALLY PREVAIL...THOUGH SOME BRIEF PERIODS
OF IFR MAY OCCUR DEPENDING ON INTENSITY OF -SHSN. SHSN WILL
TRANSITION TO LES AS COLDER AIR MOVES IN TONIGHT BUT SHOULD MAINLY
AFFECT KCMX. NORTHWEST WINDS WILL ALSO INCREASE LATE THIS EVENING
AND OVERNIGHT WITH BLSN ALSO DEVELOPING AT KCMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 537 AM EST THU MAR 8 2012
A COUPLE OF PERIODS OF GALES ON THE LAKE INTO THIS WEEKEND. FIRST
GALE EVENT IS TONIGHT WITH COLD AND UNSTABLE PROFILE OVER THE LAKE.
SHOULD SEE FREQUENT GUSTS 35-40 KTS AND HAVE ISSUED GALE WARNING FOR
ALL OF LK SUPERIOR INTO EARLY FRIDAY. HAVE ALSO POSTED HEAVY FREEZING
SPRAY WARNING FOR TONIGHT. NOT OUT OF QUESTION THAT THIS MAY BE LAST
HEAVY FREEZING SPRAY EPISODE OF WINTER.
SOUTH TO SOUTHWEST GALES THEN LOOK LIKELY LATER FRIDAY NIGHT INTO
SATURDAY AS PRESSURE GRADIENT TIGHTENS OVER LK SUPERIOR. WARM AIR
ADVECTION REGIME KEEPS HIGHER STABILITY IN LOW-LEVELS...BUT THINK
THIS WILL BE OFFSET BY VERY STRONG PRESSURE FALLS SLIDING JUST NORTH
OF LK SUPERIOR. SETUP USUALLY RESULTS IN STRONGEST WINDS OVER
EASTERN HALF OF LK SUPERIOR. WINDS SETTLE DOWN CONSIDERABLY BY LATER
SATURDAY NIGHT INTO SUNDAY. WIND DIRECTION LATER SUNDAY INTO MONDAY
WILL BE HIGHLY DEPENDANT ON TRACK OF APPROACHING LOW PRESSURE SYSTEM
FM CENTRAL PLAINS. EXPECT WINDS TO REMAIN LESS THAN 30 KTS AS THE
SYSTEM MOVES THROUGH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 4 AM TO 11 AM EST FRIDAY FOR LSZ267.
GALE WARNING FROM 1 AM TO 11 AM EST FRIDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING FROM 7 PM EST /6 PM CST/ THIS
EVENING TO 7 AM EST /6 AM CST/ FRIDAY FOR LSZ162-240>245-
248-263>265.
GALE WARNING FROM 10 PM EST /9 PM CST/ THIS EVENING TO 6 AM EST
/5 AM CST/ FRIDAY FOR LSZ162-263.
GALE WARNING FROM MIDNIGHT TONIGHT TO 8 AM EST FRIDAY FOR LSZ264-
265.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...TITUS
MARINE...JLA
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1141 AM CST THU MAR 8 2012
.AVIATION...18Z TAF ISSUANCE...
TEMPORARY RIDGING CROSSING CWA LATE THIS MORNING. VFR AT ALL
TERMINALS EXCEPT KBRD WHERE EARLIER SYSTEM HAS LEFT MVFR CEILINGS.
STRONG WINDS ALOFT BEGINNING TO MIX DOWN WITH DAYTIME WARMING OF
BDRY LYR. VIGOROUS COLD FRONT/UPPER SYSTEM APPROACHING THE CWA QUICKLY
AND EXPECT A BURST OF MDT/POSSIBLY HEAVY SNOW TO ACCOMPANY THIS
SYSTEM THIS AFTN. USED TEMPO DUE TO FAST MOVING NATURE OF FEATURE
AND EXPECT IFR DURING THE SNOW. RAPID CLEARING EXPECTED THIS
EVENING FROM WEST TO EAST AS DEEP LAYER DRYING OCCURS BEHIND
FRONT.
&&
.PREV DISCUSSION... /ISSUED 1000 AM CST THU MAR 8 2012/
UPDATE...
ADDED SCATTERED SNOW SHOWERS ACROSS THE SRN COUNTIES THIS MORNING
TO ACCOUNT FOR A SMALL CLUSTER OF SNOW SHOWERS MOVING FROM E-CNTRL
MN INTO WI. STILL ANTICIPATING THE CONVECTIVE SNOW SHOWERS TO
DEVELOP THIS AFTERNOON...AND AFTER LOOKING AT THE LATEST HIGH- RES
SHORT TERM MODELS...LOOKS VERY UNSTABLE IN THE LOW AND MID
LEVELS... WITH STEEP LAPSE RATES AND 50-80 J/KG OF LOW-LVL
CAPE...AND ALSO VERY SUPPORTIVE ALOFT FOR A QUICK INCH OF SNOW
ACCUMULATION. WINDS WILL INCREASE FROM THE NW THIS AFTERNOON...AND
COMBINE WITH THE SNOW SHOWERS TO PRODUCE AREAS OF BLOWING SNOW.
VISIBILITIES COULD BE REDUCED TO A MILE OR LESS AT TIMES IN THE
BLOWING SNOW. A STRONG 140KT JET WILL PUSH IN FROM THE NW...WITH
THE NORTHLAND IN THE LEFT EXIT REGION...ALSO A STRONG 500MB VORT
MAX WILL ADVECT INTO THE REGION TO HELP WITH VERTICAL MOTION.
SYSTEM SHOULD MOVE THROUGH VERY RAPIDLY AS HIGH PRESSURE BUILDS IN
ON THE BACK SIDE.
PREV DISCUSSION... /ISSUED 654 AM CST THU MAR 8 2012/
AVIATION.../12Z TAF ISSUANCE/
ANOTHER COLD FRONT WILL TRACK SEWD ACROSS THE NORTHLAND THIS
AFTERNOON AND EVENING...BRINGING INCREASING CLOUD COVER AND AREAS
OF LIGHT SNOW TO THE REGION. CIGS AND VSBYS ASSOCIATED WITH THE
FROPA WILL BE IN THE MVFR/LOW VFR RANGE. THE SNOW SHOULD END LATE
THIS EVENING OVER OVERNIGHT AND SKIES WILL SCTR OUT.
PREV DISCUSSION... /ISSUED 403 AM CST THU MAR 8 2012/
SHORT TERM...THE SHORT TERM FOCUS IS ON WINDS AND SNOW SHOWER
POTENTIAL ACROSS THE NORTHLAND.
AT 330 AM...FAIRLY WIDESPREAD CLOUD COVER WAS MOVING ACROSS THE
NORTHLAND ALTHOUGH THERE WERE SEVERAL AREAS OF THIN CLOUDS.
TEMPERATURES RANGED FROM THE UPPER 20S IN PORTIONS OF NW WI...TO
NEAR 10 ABOVE FAR NORTHWEST.
NORTHWEST FLOW WILL PERSIST ACROSS THE NORTHLAND TODAY. STRONG CAA
WILL BECOME FAIRLY NEUTRAL THROUGHOUT THE DAY. THE NAM INDICATES
THAT AT LEAST A COUPLE SHORTWAVES WILL MOVE THROUGH THE REGION IN
NW FLOW TODAY. EACH WILL BE CAPABLE OF GENERATING SOME SNOW
SHOWERS...BUT THE BEST CHANCE SHOULD BE ACROSS THE NORTH IN THE
AFTERNOON AND EARLY EVENING. WITH COLD AIR ALOFT AND SOME SURFACE
HEATING BETWEEN SNOW SHOWERS...THINK SOME OF THE SNOW SHOWERS
COULD BE FAIRLY STRONG THIS AFTERNOON...EVEN BRINGING SOME GUSTY
WINDS WITH THE SNOW SHOWERS.
THE BIGGER STORY FOR TODAY MAY BE THE STRONG WINDS EXPECTED TO
MOVE INTO THE CWA DURING THE AFTERNOON AND EVENING. HAVE BROUGHT
WINDS UP QUITE A BIT. THE RUC SHOWS STRONG WINDS ALOFT MIXING DOWN
TO THE SURFACE. THE FORECAST SOUNDINGS FOR DULUTH INDICATE 40-50
KNOTS WORKING ITS WAY TO JUST ABOVE THE SURFACE. AS A RESULT...WE
COULD EASILY SEE SOME 20 TO 30 MPH SUSTAINED WINDS THIS AFTERNOON
WITH HIGHER GUSTS AS WELL. WINDS WILL THEN DECREASED OVERNIGHT AS
SKIES CLEAR FROM THE WEST. HAVE DROPPED TEMPS CONSIDERABLY FOR
TONIGHT...CLOSER TO THE MAV GUIDANCE. THIS SHOULD RESULT IN
TEMPERATURES DROPPING BELOW ZERO IN THE NORTH.
FRIDAY SHOULD BE A BIT WARMER...AS WAA PUSHES ACROSS THE REGION.
SHOULD BE SOMEWHAT OF AN INCREASE IN CLOUDS...ESPECIALLY IN THE
NORTH. THINK MOST OF THE PRECIPITATION SHOULD REMAIN IN CANADA.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY. THE EXTENDED
FORECAST PERIOD WILL START OUT DRY AND MILD UNDER WITH A UPPER
RIDGE BUILDING OVER THE WRN GREAT LAKES DUE TO STRONG SWRLY FLOW
IN THE LOW-LEVELS. HOWEVER THE RIDGE WILL GIVE WAY TO A LOW
PRESSURE SYSTEM DEVELOPING OVER THE CNTL PLAINS WHICH IS PROGGED
TO LIFT NEWD OVER THE GREAT LAKES SUNDAY INTO MONDAY. THERE ARE
STILL SOME SIGNIFICANT DIFFERENCES BETWEEN THE VARIOUS NWP MODEL
SOLUTIONS...WITH THE NAM/GFS TAKING THE LOW OFF TO THE SOUTH AND
EAST OF OUR CWA...WHILE THE ECMWF/GEM BRING IT RIGHT OVER THE
NORTHLAND. DUE TO THESE DIFFERENCES...WE WILL KEEP POPS IN THE
CHANCE CATEGORY ATTM. PRECIP TYPE SHOULD BE MAINLY RAIN DUE TO THE
WARM AIRMASS IN PLACE ACROSS THE UPPER MIDWEST. BUT IF THE DYNAMIC
LIFT IS STRONG ENOUGH...THERE COULD BE A WINTRY MIX SUNDAY NIGHT
AND MONDAY MORNING. AFTER THE LOW MOVES OFF TO THE EAST...AN
UNSEASONABLY WARM AND DRY PATTERN WILL DEVELOP ACROSS THE
NORTHLAND NEXT WEEK AS SOUTHWEST FLOW DOMINATES ACROSS THE CTRL
PART OF THE COUNTRY THROUGH WEDNESDAY.
AVIATION.../06Z TAF ISSUANCE/
MVFR AND ISOLATED IFR IN CLOUDS AND SNOW IN A FRONTAL BAND SHOULD
MOVE OUT OF THE IWD AND GOGEBIC RANGE AREA LATE TONIGHT. MN NORTH
SHORE AND REST OF NORTHWEST WISCONSIN...MVFR IN CLOUDS IMPROVING
TO VFR SCATTERED WITH AREAS OF BROKEN CLOUDS BY DAY BREAK THURSDAY
MORNING. THE REST OF NORTHEAST MN...VFR THROUGH EARLY MORNING.
AREAS OF LOW-END VFR IN CLOUDS WILL DEVELOP MIDMORNING ACROSS
COASTAL WI AND NORTH OF ROUTE 2 IN NORTHEAST MN AFTER MIDMORNING
THURSDAY...AND PERSIST TILL LATE THURSDAY AFTERNOON. VFR CLEAR
BEGINNING THURSDAY EVENING. BRISK NORTHWEST WINDS...GUSTING TO 30
MPH...WILL CONTINUE INTO LATE THURSDAY AFTERNOON...AND SUBSIDE
DURING THURSDAY EVENING.
&&
.POINT TEMPS/POPS...
DLH 31 7 29 25 / 30 30 0 10
INL 31 -5 32 22 / 40 20 10 10
BRD 34 5 35 29 / 30 10 0 0
HYR 33 5 33 27 / 30 30 0 10
ASX 34 10 30 25 / 30 30 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
AVIATION...CANNON
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
ISSUED BY NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1143 AM CST THU MAR 8 2012
.UPDATE...
ISSUED AT 707 AM CST THU MAR 8 2012
HAVE UPDATE SHORT TERM FORECAST TO REFLECT DRYING TREND OVER THE
NORTHERN PART OF THE CWA. ALSO MENTIONED THE CHANCE FOR SNOW OR
SLEET THIS MORNING IN CENTRAL MISSOURI AS THE CURRENT OB AT KSZL
HAS -PL. OTHERWISE...REST OF FORECAST STILL HOLDS.
BRITT
&&
.SHORT TERM...
ISSUED AT 316 AM CST THU MAR 8 2012
(TODAY AND TONIGHT)
COLD FRONT HAS MOVED ABOUT HALFWAY THROUGH THE CWA AND IS CURRENTLY
ENTERING THE NORTHWESTERN PART OF THE ST. LOUIS METRO AREA. SHOWERS
AND SCATTERED THUNDERSTORMS HAVE DEVELOPED ALONG AND AHEAD OF THE
FRONT IN A BROAD AREA OF 950-850MB MOISTURE CONVERGENCE. THIS
MOISTURE CONVERGENCE IS COINCIDENT WITH LARGE SCALE ASCENT FROM
MID-LEVEL CURRENTLY PASSING THROUGH THE UPPER MIDWEST. A SECOND
LARGER AREA OF PRECIPITATION IS MOVING ACROSS WESTERN MISSOURI WHICH
IS BEING GENERATED BY THE LARGE SCALE ASCENT ON THE TAIL END OF THE
TROUGH AND A LITTLE STRONGER LOW LEVEL CONVERGENCE ON THE NOSE OF A
50KT LOW LEVEL JET OVER THE PLAINS. THIS FORCING WILL CONSOLIDATE
THROUGH THE MORNING PER THE RUC AS THE LOW LEVEL JET VEERS WITH
TIME. THIS SHOULD BE ENOUGH TO KEEP LIKELY OR CATEGORICAL RAIN
CHANCES GOING FOR ABOUT THE SOUTHERN TWO-THIRDS OF THE CWA EARLY
THIS MORNING...WITH A GRADUAL DIMINISHING TREND THROUGH THE DAY AS
THE FORCING PUSHES SOUTH AND EAST. THERE SHOULD BE ENOUGH
INSTABILITY TO KEEP AT LEAST A MENTION OF SCATTERED THUNDERSTORMS
THIS MORNING ALONG AND AHEAD OF THE 850MB COLD FRONT. CAN`T RULE
OUT THE POTENTIAL FOR SOME SNOW OR SLEET ON THE NORTHERN FRINGE OF
THE PRECIPITATION WHERE RUC SOUNDINGS ARE SHOWING THE LOW LEVEL
THERMAL PROFILES COOLING NEAR 0C ABOUT THE TIME THAT THE
PRECIPITATION ENDS. THINK THIS WILL BE A SHORT LIVED EVENT AND
MAINLY FOUND WHERE CONVECTION IS MORE CONCENTRATED. TONIGHT SHOULD
BE DRY AS SUBSIDENCE SETS IN BEHIND THE NORTHERN STREAM TROUGH.
TEMPERATURES SHOULD REMAIN STEADY OR SLOWLY FALL THROUGH THE DAY
OVER THE SOUTHERN HALF OF THE CWA EXTENSIVE CLOUD COVER AND DECENT
COLD AIR ADVECTION BEHIND THE FRONT. GFS MOS TEMPERATURES LOOK A
BIT TOO WARM TONIGHT GIVEN THE MAINLY CLEAR SKIES AND WINDS
TURNING LIGHT AS THE SURFACE RIDGE SETTLES INTO THE AREA.
BRITT
&&
.LONG TERM...
ISSUED AT 330 AM CST THU MAR 8 2012
(FRIDAY THROUGH NEXT WEDNESDAY)
SFC HIGH BUILDS IN BEHIND THE DEPARTING CDFNT ON FRI WITH DRY WX
EXPECTED ON FRI AND MOST OF SAT BEFORE ANOTHER ROUND OF PCPN DVLPS
ON SAT NIGHT AS AN UPPER LOW OVER AZ/NM BEGINS LIFTING NEWD THROUGH
THE CENTRAL CONUS. MODELS CONTINUE TO STRUGGLE WITH HOW AND WHEN
THIS LOW LIFTS NEWD. THE PREVIOUS FOUR RUNS OF THE ECMWF WERE
EVENLY SPLIT BETWEEN KEEPING THE VORT CENTER INTACT /00Z RUNS ON
MARCH 7TH AND 8TH/ AND SPLITTING IT INTO TWO VORT MAXES /12Z RUNS ON
MARCH 6TH AND 7TH...SIMILAR TO WHAT THE GFS HAS BEEN DEPICTING FOR
THE LAST SEVERAL DAYS/. 08/00Z GEM REMAINS SIMILAR TO THE 07/00Z
RUN AND SHOWS THE LOW RETROGRADING TO BAJA CA THEN MOVING THROUGH
MEXICO BEFORE LIFTING THROUGH TX AND INTO NWRN MO. THESE LARGE
DIFFERENCES BETWEEN THE 3 MODELS APPEAR TO STEM FROM DIFFERENT
HANDLING OF THE INTERACTION BETWEEN THE CLOSED LOW AND A SUBTLE
AREA OF ENHANCED VORTICITY THAT SHOULD BE MOVING THROUGH ID/NV AT
08/12Z. DESPITE THE DIFFERENT DETAILS...MODEL SOLUTIONS ALL
SUGGEST ANOTHER ROUND OF PCPN SOMEWHERE BETWEEN SAT NIGHT AND MON
AS THE CLOSED LOW /OR ITS REMNANTS/ FINALLY LIFTS NEWD. WAA SHRA
EXPECTED TO DVLP FIRST FOLLOWED BY AN INCREASE IN PCPN COVERAGE AS
LARGE SCALE LIFT INCREASES WITH THE APPROACHING VORT MAX. MODELS
ARE OFTEN TOO QUICK TO BRING A CLOSED LOW BACK INTO THE PREVAILING
FLOW THEREFORE I WOULD NOT BE SURPRISED IF THIS OVERALL FCST
SCENARIO ENDS UP BEING DELAYED BY A DAY OR SO AS THE MODELS CATCH
UP TO THE ATMOSPHERE.
KANOFSKY
&&
.AVIATION...
ISSUED AT 1141 AM CST THU MAR 8 2012
AREAS OF RAIN SHIFTED SOUTH OF THE TERMINALS THIS MORNING AS DRY
AIR WITHIN THE GREATS LAKES TROUGH SHIFTED INTO NORTHERN MISSOURI.
THIS HAS ALSO BROUGHT HIGHER CEILINGS TO THE TERMINALS...WITH VFR
CONDITIONS PREVAILING AT ALL THE TERMINALS NOW. EXPECT THE VFR
CONDITIONS TO PREVAIL THROUGH THE NEXT 30 HOURS. TERMINALS IN THE
VICINITY OF THE ILLINOIS-MISSOURI BORDER WILL CONTINUE TO EXPECT
GUSTY WINDS THROUGH THE EARLY AFTERNOON HOURS...THOUGH TOWARDS THE
MID TO LATE AFTERNOON HOURS WIND CONDITIONS SHOULD CALM TO AROUND
12 KNOTS AS THE COOL DOME OF HIGH PRESSURE OVERSPREADS THE REGION.
OVERNIGHT...VFR CONDITIONS WILL PERSIST AND THE WIND WILL SETTLE
TO AROUND 5 KNOTS FROM THE NORTHWEST.
SPECIFICS FOR KSTL...
VFR CONDITIONS EXPECTED TO PREVAIL AT THE KSTL TERMINAL THROUGH
THE NEXT 30 HOURS. ONLY ITEM TO WATCH FOR WILL BE THE SHIFT IN
WIND TOWARDS THE LATE PERIODS OF THE TAF CYCLE. OVERNIGHT WINDS
WILL CALM TO AROUND 5 KNOTS FROM THE NORTHWEST...BUT DURING THE
MID TO LATE MORNING HOURS FRIDAY EXPECT THE WIND TO PICK UP IN
SPEED AND SHIFT CLOSER TO DUE NORTH.
CUTTER
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1020 AM CST THU MAR 8 2012
.DISCUSSION...
MAIN CHALLENGES REMAIN MAX TEMPS AND FRONTAL PASSAGE WITH
-SN/BLSN. COLD FRONT NOW STARTING TO ENTER THE NW PORTION OF THE
FORECAST AREA WITH -SN REDUCING VISIBILITIES. MODEL SOUNDINGS STILL
SHOW AN ADIABATIC LAYER IN THE LOW LEVELS SO WIND FORECAST
REMAINS GOOD. EXPECT TEMPS TO LEVEL OFF A BIT AFTER 18Z WHEN THE
COLD ADVECTION IS EXPECTED TO BEGIN PUSHING IN TO THE NORTHERN
AREAS.
AVIATION...
MAINLY VFR CONDS THIS MORNING WILL LOWER TO MVFR THIS AFTN WITH THE
APPROACH OF THE COLD FRONT. NW WINDS WILL INCREASE IN ALL AREAS THIS
AFTERNOON AND GUSTS TO 35KT WILL BE POSSIBLE. THERE COULD BE SOME
BLSN IN THE NORTH THIS AFTERNOON...AND VSBYS SHOULD BE REDUCED ALONG
WITH SOME SNOW SHOWERS THIS AFTERNOON. WINDS SHOULD QUICKLY
SUBSIDE AFTER SUNSET.
&&
.PREV DISCUSSION... /ISSUED 402 AM CST THU MAR 8 2012/
DISCUSSION...
THE MAIN CHALLENGES WILL BE WIND AND BLOWING SNOW POTENTIAL TODAY
AND TEMPS THROUGHOUT. MODELS ARE NOT HANDLING THIS INITIAL SNOW
BAND OVER THE REGION WELL AT ALL...WITH THE RUC DOING THE BEST IN
THE NEAR TERM. SOME REPORTS AND RADAR INDICATING A NARROW BAND OF
1-2 INCHES FROM GRAFTON TO MINTO TO MANVEL INTO THE GRAND FORKS
AREA. WILL USE A MODEL BLEND AND NOT WARM THINGS UP TOO QUICKLY
WITH STILL A DECENT SNOW PACK OVER THE REGION.
FOR TODAY...SEVERAL SHORTWAVES WILL ROTATE THROUGH THE REGION. A
COLD FRONT WILL PASS THROUGH THE AREA THIS AFTERNOON...ALONG WITH
ABOUT 40-50KT TO MIX THROUGHOUT THE ENTIRE FORECAST AREA. A STRONG
PRESSURE RISE WILL ALSO COME DOWN THE VALLEY...SO EXPECT WINDY
CONDITIONS THIS AFTERNOON WITH GUSTS TO 40 MPH LIKELY. WILL ISSUE
A WINTER WEATHER ADVISORY FOR THE NORTHERN VALLEY WITH SOME SNOW
THIS MORNING...AND SNOW SHOWERS WITH THE FRONT SO THERE IS FRESH
SNOW TO BLOW AROUND. THE STRONG WINDS SHOULD CAUSE BLOWING SNOW
AND OPEN COUNTRY VSBY ISSUES...ESPECIALLY WHEN SNOW SHOWERS
COMBINE WITH INCREASING WINDS THIS AFTERNOON. WILL GO WITH A WIND
ADVISORY FOR THE REST OF THE REGION FROM 18Z-00Z. TEMPS WON/T WARM
TOO MUCH GIVEN COLD FRONT AND INCREASING CLOUDS AND ISOLATED SNOW
SHOWERS.
FOR TONIGHT...SFC HIGH SETTLES OVER THE REGION AND IT WILL GET
COLD IN THE EAST...WHERE TEMPS SHOULD DIP BELOW ZERO. EXPECT
WARMER TEMPS TO THE WEST WITH RETURN FLOW BEGINNING AFTER 06Z.
ON FRI...SOUTHERLY WINDS WILL INCREASE...ALTHOUGH WITH A COLD
START TEMPS WON/T GET TOO WARM IN THE VALLEY. HAVE LOWERED TEMPS
SOME FROM PREVIOUS FORECAST ALTHOUGH WITH SUNSHINE EXPECT AT LEAST
SOME MELTING.
ON SAT/SUN...MORE OF A WESTERLY SFC FLOW AND WARMING THERMAL
FIELDS AT ALL LEVELS WILL MEAN TEMPS WELL ABOVE NORMAL. EXPECT THE
WARMEST READINGS IN THE WEST AND TREED AREAS IN THE EAST...WITH
COLDER READINGS ON THE VALLEY FLOOR.
ON MON...ANY PRECIP SHOULD REMAIN SOUTH OF THE AREA AND WILL KEEP
IT DRY WITH WARM WEATHER CONTINUING NEXT WEEK.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ028>030-038-039-
049-052-053.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
NDZ006>008-014>016-024-026-027-054.
MN...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ002-003-006-009-
016-017-022>024-027>032-040.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ001-
004-005-007-008-013>015.
&&
$$
HOPKINS
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
245 PM CST THU MAR 8 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
A COLD FRONT IS CURRENTLY MOVING SOUTHEAST OUT OF ND THIS
AFTERNOON. COMBINED WITH MOSTLY CLEAR SKIES AS HIGH PRESSURE
BUILDS INTO THE DAKOTAS TONIGHT AND SNOW COVER ON THE
GROUND...TEMPS WILL FALL INTO THE SINGLE DIGITS TO LOWER TEENS IN
THE EAST. WHERE GROUND IS BARE...EXPECT LOWS TO DROP INTO THE
UPPER TEENS TO MID 20S.
WINDS WILL DIMINISH BETWEEN 0Z AND 03Z AFTER THE FROPA. UNTIL THEN
STRONGEST WINDS WILL BE BETWEEN 21Z AND 0Z. MOST AREAS WILL STAY
BELOW ADVISORY CRITERIA..THOUGH THE 17Z RUC INDICATES THAT CORSON
COUNTY AND LOCAL AREAS IN THE FAR NORTHEAST CORNER MAY BRIEFLY SEE
SUSTAINED WINDS NEAR 30 MPH. DECIDED THE IMPACT WAS NOT SUFFICIENT
ENOUGH TO MERIT AN ADVISORY. AT THIS POINT SNOW PACK IS WET AND
HEAVY ENOUGH TO LIMIT ANY BLOWING SNOW.
WITH DRY WEATHER AND A WARMING TREND CONTINUING THROUGH
SATURDAY...WILL NEED TO KEEP AN EYE ON ANY FIRE WEATHER CONCERNS
IN SNOW FREE AREAS ACROSS CENTRAL SD. EXPECT SURFACE TEMPS TO CLIMB
INTO THE LOWER 50S IN THE EAST TO LOWER 70S IN SOUTHCENTRAL SD BY
SATURDAY AS H85 TEMPS RISE TO NEAR +13.
.LONG TERM...SUNDAY THROUGH THURSDAY
AS THE PERIOD OPENS...THERE IS A LONGWAVE RIDGE OF HIGH PRESSURE
POSITIONED OVER THE WESTERN CONUS /ESPECIALLY THE PAC NW/ AND A
CUT-OFF LOW SPINNING/MEANDERING OVER THE DESERT SW. BY
MONDAY...THIS CUT-OFF LOW IS FINALLY EJECTING OUT OF THE SWRN
CONUS ACROSS THE CENTRAL AND NORTHERN PLAINS. TEMP-WISE...CURRENT
SOLUTIONS SUGGEST IT WILL BE WARM ENOUGH THAT ANY PRECIPITATION
COMING INTO THE FAR EASTERN CWA SUNDAY NIGHT OR MONDAY IN
ASSOCIATION WITH THIS LOW WOULD BE RAIN. THE REMAINDER OF THE LONG
TERM SEES THE UPPER RIDGE ACROSS THE WEST REPOSITION TO THE
EASTERN GREAT LAKES/EASTERN CONUS...WHILE A BROAD LONGWAVE TROF
DEVELOPS ACROSS THE WEST COAST WITH VARIOUS TRANSIENT S/WS PROGGED
TO WORK INLAND ACROSS WASHINGTON..IDAHO AND MONTANA BEFORE BEING
REDIRECTED NORTH AND EAST ACROSS NORTH DAKOTA...NORTHERN MN AND SC
CANADA. LARGELY...THIS CWA IS NOT EXPECTED TO RECEIVE MEASURABLE
PRECIPITATION BETWEEN MONDAY NIGHT AND THURSDAY. OTHER THAN A COLD
FRONT PROGGED TO PASS THROUGH WEDNESDAY/WEDNESDAY NIGHT BRINGING A
TEMPORARY COOL DOWN...THERE SEEMS TO BE NO END IN SIGHT TO
MILD...UNSEASONABLY WARM /MUCH ABOVE NORMAL/ AIR OVER THE CWA NEXT
WEEK.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED THRU THE TAF PERIOD WITH SCT MID AND
HIGH LEVEL CLOUDS AROUND FROM THIS AFTERNOON THROUGH MID-EVENING.
ACROSS FAR NORTHEAST SOUTH DAKOTA...THE KABR AND KATY TERMINALS
MAY BE FLIRTING WITH SOME 3000FT AGL CIGS LATE THIS
AFTERNOON/EARLY THIS EVENING. OTHERWISE...SKIES SHOULD CLEAR OFF
BY LATE THIS EVENING. BREEZY WESTERLY SFC WINDS THIS AFTERNOON
WILL SWITCH AROUND TO THE NORTH IN THE FAR NORTHEAST CORNER OF
SOUTH DAKOTA LATE THIS AFTERNOON AND INCREASE TO 20 TO 30 KNOTS
FOR A FEW HOURS. KABR AND KATY MAY GET INTO THESE STRONG
NORTHERLY WINDS VERY BRIEFLY EARLY THIS EVENING. MORE
LIKELY...THESE TWO TERMINALS...LIKE KPIR AND KMBG...WILL JUST
GRADUALLY LOOSE THE GUST CHARACTER BY EARLY THIS EVENING AS WINDS
SLOWLY SWING AROUND FROM WEST TO NORTH TO EAST BY LATE
TONIGHT...AND FINALLY AROUND TO THE SOUTH-SOUTHEAST BY FRIDAY
MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...WISE
LONG TERM...DORN
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1204 PM CST THU MAR 8 2012
.UPDATE...
ADJUSTED TEMPERATURES ACROSS ROBERTS/BIG STONE/TRAVERSE COUNTIES
AFTER 21Z. AS A WEAK COLD FRONT MOVES OUT OF ND LATER TODAY...IT
WILL CAUSE A NON-DIURNAL TEMP TREND...COOLING THINGS OFF IN THE
NE. 15Z RUC INDICATES ANY ASSOCIATED LIGHT PRECIP WILL REMAIN OFF
TO THE EAST OF THIS CWA SO DID NOT ADD IN ANY FLURRIES...THOUGH
THEY ARE NOT COMPLETELY OUT OF THE QUESTION IF THE WAVE FOLLOWS
ITS CURRENT TRAJECTORY SO WILL NEED TO KEEP AN EYE ON THAT.
OTHERWISE CURRENT FORECAST LOOKS TO BE ON TRACK AND NO FURTHER
CHANGES WERE MADE.
SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
THE MODELS CONTINUE TO SHOW A WARM UP THROUGH THE SHORT TERM. FOR
TODAY...A COUPLE SHORT WAVES WILL AFFECT THE REGION ALONG WITH A
COLD FRONT. THE FIRST SHORT WAVE WAS MOVING ACROSS NORTHERN SD
THIS MORNING BRINGING SOME MID LEVEL CLOUDS ALONG WITH A FEW
FLURRIES IN NORTHEAST SD AND WC MN EARLY THIS MORNING. THE OTHER
STRONGER SHORT WAVE WILL DROP SOUTHEAST OUT OF CANADA AND ACROSS
NORTHERN MN TODAY. THE PRECIPITATION WITH THIS WAVE WILL REMAIN
TO OUR NORTHEAST. THE ISSUE WITH THIS WAVE WILL BE THE COLD FRONT
DROPPING IN BEHIND IT THIS AFTERNOON AND SWEEPING ACROSS EASTERN
SD. AS A RESULT...WEST WINDS THIS MORNING WILL TURN NORTHWEST INTO
THE AFTERNOON AND INCREASE QUITE A BIT. AS THE CAA INCREASES AND
THE MIXING LAYER DEEPENS THIS AFTERNOON...EXPECT IT TO BECOME
WINDY ACROSS MUCH OF NORTHEAST SD AND WC MN THIS AFTERNOON. WILL
BE CLOSE TO WIND ADVISORY WINDS. HIGH TEMPERATURES WILL LIKELY BE
REACHED IN ADVANCE OR JUST BEHIND THE COLD FRONT THIS AFTERNOON.
LOWERED AFTERNOON HIGHS SOME EAST IN THE CWA. THE SNOW COVER ALSO
REMAINS PRETTY EXTENSIVE EAST IN THE CWA WITH AMOUNTS FROM 2 TO
OVER 10 INCHES. THIS WILL CONTINUE TO HAVE AN AFFECT ON HIGH
TEMPERATURES INTO FRIDAY.
SURFACE HIGH PRESSURE WILL PUSH IN TONIGHT WITH WINDS FALLING OFF
QUICKLY EARLY THIS EVENING. THIS WILL PUSH EAST ON FRIDAY WITH
WINDS TURNING SOUTH TO SOUTHWEST AND INCREASING. EXPECT MOSTLY
CLEAR SKIES TONIGHT WITH LIGHT WINDS. DROPPED TEMPERATURES SOME
EAST IN THE CWA FOR TONIGHT. FOR FRIDAY AND SATURDAY...THE MODELS
SHOW UPPER LEVEL RIDGING BUILDING AND REMAINING OVER THE REGION AS
VERY WARM 85H AIR OF OVER +10C PUSHES IN ON FRIDAY AND REMAINS
THROUGH SATURDAY. FRIDAY WILL BE WARMER WITH BREEZY/WINDY
SOUTHWEST WINDS WITH A TIGHT SURFACE PRESSURE GRADIENT AND
INCREASING MIXING LAYER. THE SNOW COVER SHOULD STILL KEEP HIGHS IN
THE MID TO UPPER 40S EAST IN THE CWA. BY SATURDAY...MUCH OF THE
SNOW COVER WILL BE DIMINISHED WITH HIGHS IN THE 50S AND 60S CWA
WIDE. IT WILL BE DRY THROUGH SATURDAY WITH VERY LITTLE IF ANY
CLOUD COVER.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
HIGH TEMPERATURE FORECASTING IS THE MAIN CHALLENGE THROUGH THE
EXTENDED PERIOD...AND DETERMINING JUST HOW WARM IT WILL GET AS
VERY MILD AIR MASS STREAMS ACROSS THE NORTHERN PLAINS. 850 MB AND
EVEN 925 MB TEMPS SOAR INTO THE TEENS ABOVE CELSIUS DURING SEVERAL
PERIODS FROM LATE THIS WEEKEND INTO THE MIDDLE OF NEXT WEEK. LATE
THIS WEEKEND INTO EARLY NEXT WEEK...PORTIONS OF THE NORTHEASTERN
CWA COULD STILL BE DEALING WITH SNOW COVER BUT EXPECT THIS TO BE
QUICKLY DIMINISHING THROUGH THE TIME PERIOD. MAY NEED TO TEMPER
READINGS ON SUNDAY ACROSS THE FAR NORTHEAST BUT WILL HAVE TO SEE
HOW SNOW COVER MELTS UNTIL THEN. 00Z GFS STILL SHOWING A COOLING
FRONTAL PASSAGE FOR TUESDAY WHICH WOULD KNOCK TEMPS BACK
SOME...BUT THIS HAS NO SUPPORT FROM 00Z RUNS OF THE EC OR CANADIAN
MODELS. FOR RIGHT NOW CURRENT FORECAST HIGHS ON TUESDAY ARE A FEW
TICKS LOWER THEN MONDAY...BUT STILL VERY MILD NONETHELESS WITH
READINGS IN THE 50S AND 60S. IN FACT...THE ENTIRE EXTENDED PERIOD
IS SHAPING UP VERY MILD WITH READINGS MOSTLY IN THE 50S AND
60S...POSSIBLY EVEN A FEW LOW 70S OVER THE SOUTHWEST CWA.
AS FOR PRECIPITATION...IT LOOKS DRY THROUGHOUT THE PERIOD AT THIS
TIME. WILL NEED TO WATCH A SHORTWAVE THAT TRAVELS NORTHWARD ACROSS
THE CENTRAL PLAINS MONDAY INTO MONDAY NIGHT. FOR THE MOST
PART...MODELS HAVE KEPT THIS SYSTEM TO THE EAST THE PAST COUPLE
DAYS. THE MOST RECENT RUNS OF THE EC AND CANADIAN NUDGE THIS BACK
WEST NOW AND BRING WESTERN EDGE OF PRECIP SHIELD NEAR I-29
CORRIDOR. GFS REMAINS FASTER AND FARTHER EAST WITH WAVE. SOMETHING
TO WATCH AS POPS MAY NEED TO BE ADDED TO THE FAR EASTERN COUNTIES
IF MODELS KEEP NUDGING THIS SYSTEM FURTHER WEST.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED THRU THE TAF PERIOD WITH SCT MID AND
HIGH LEVEL CLOUDS AROUND FROM THIS AFTERNOON THROUGH MID-EVENING.
ACROSS FAR NORTHEAST SOUTH DAKOTA...THE KABR AND KATY TERMINALS
MAY BE FLIRTING WITH SOME 3000FT AGL CIGS LATE THIS
AFTERNOON/EARLY THIS EVENING. OTHERWISE...SKIES SHOULD CLEAR OFF
BY LATE THIS EVENING. BREEZY WESTERLY SFC WINDS THIS AFTERNOON
WILL SWITCH AROUND TO THE NORTH IN THE FAR NORTHEAST CORNER OF
SOUTH DAKOTA LATE THIS AFTERNOON AND INCREASE TO 20 TO 30 KNOTS
FOR A FEW HOURS. KABR AND KATY MAY GET INTO THESE STRONG
NORTHERLY WINDS VERY BRIEFLY EARLY THIS EVENING. MORE
LIKELY...THESE TWO TERMINALS...LIKE KPIR AND KMBG...WILL JUST
GRADUALLY LOOSE THE GUST CHARACTER BY EARLY THIS EVENING AS WINDS
SLOWLY SWING AROUND FROM WEST TO NORTH TO EAST BY LATE
TONIGHT...AND FINALLY AROUND TO THE SOUTH-SOUTHEAST BY FRIDAY
MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...MOHR
LONG TERM...TMT
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1029 AM CST THU MAR 8 2012
.UPDATE...
ADJUSTED TEMPERATURES ACROSS ROBERTS/BIG STONE/TRAVERSE COUNTIES
AFTER 21Z. AS A WEAK COLD FRONT MOVES OUT OF ND LATER TODAY...IT
WILL CAUSE A NON-DIURNAL TEMP TREND...COOLING THINGS OFF IN THE
NE. 15Z RUC INDICATES ANY ASSOCIATED LIGHT PRECIP WILL REMAIN OFF
TO THE EAST OF THIS CWA SO DID NOT ADD IN ANY FLURRIES...THOUGH
THEY ARE NOT COMPLETELY OUT OF THE QUESTION IF THE WAVE FOLLOWS
ITS CURRENT TRAJECTORY SO WILL NEED TO KEEP AN EYE ON THAT.
OTHERWISE CURRENT FORECAST LOOKS TO BE ON TRACK AND NO FURTHER
CHANGES WERE MADE.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
THE MODELS CONTINUE TO SHOW A WARM UP THROUGH THE SHORT TERM. FOR
TODAY...A COUPLE SHORT WAVES WILL AFFECT THE REGION ALONG WITH A
COLD FRONT. THE FIRST SHORT WAVE WAS MOVING ACROSS NORTHERN SD
THIS MORNING BRINGING SOME MID LEVEL CLOUDS ALONG WITH A FEW
FLURRIES IN NORTHEAST SD AND WC MN EARLY THIS MORNING. THE OTHER
STRONGER SHORT WAVE WILL DROP SOUTHEAST OUT OF CANADA AND ACROSS
NORTHERN MN TODAY. THE PRECIPITATION WITH THIS WAVE WILL REMAIN
TO OUR NORTHEAST. THE ISSUE WITH THIS WAVE WILL BE THE COLD FRONT
DROPPING IN BEHIND IT THIS AFTERNOON AND SWEEPING ACROSS EASTERN
SD. AS A RESULT...WEST WINDS THIS MORNING WILL TURN NORTHWEST INTO
THE AFTERNOON AND INCREASE QUITE A BIT. AS THE CAA INCREASES AND
THE MIXING LAYER DEEPENS THIS AFTERNOON...EXPECT IT TO BECOME
WINDY ACROSS MUCH OF NORTHEAST SD AND WC MN THIS AFTERNOON. WILL
BE CLOSE TO WIND ADVISORY WINDS. HIGH TEMPERATURES WILL LIKELY BE
REACHED IN ADVANCE OR JUST BEHIND THE COLD FRONT THIS AFTERNOON.
LOWERED AFTERNOON HIGHS SOME EAST IN THE CWA. THE SNOW COVER ALSO
REMAINS PRETTY EXTENSIVE EAST IN THE CWA WITH AMOUNTS FROM 2 TO
OVER 10 INCHES. THIS WILL CONTINUE TO HAVE AN AFFECT ON HIGH
TEMPERATURES INTO FRIDAY.
SURFACE HIGH PRESSURE WILL PUSH IN TONIGHT WITH WINDS FALLING OFF
QUICKLY EARLY THIS EVENING. THIS WILL PUSH EAST ON FRIDAY WITH
WINDS TURNING SOUTH TO SOUTHWEST AND INCREASING. EXPECT MOSTLY
CLEAR SKIES TONIGHT WITH LIGHT WINDS. DROPPED TEMPERATURES SOME
EAST IN THE CWA FOR TONIGHT. FOR FRIDAY AND SATURDAY...THE MODELS
SHOW UPPER LEVEL RIDGING BUILDING AND REMAINING OVER THE REGION AS
VERY WARM 85H AIR OF OVER +10C PUSHES IN ON FRIDAY AND REMAINS
THROUGH SATURDAY. FRIDAY WILL BE WARMER WITH BREEZY/WINDY
SOUTHWEST WINDS WITH A TIGHT SURFACE PRESSURE GRADIENT AND
INCREASING MIXING LAYER. THE SNOW COVER SHOULD STILL KEEP HIGHS IN
THE MID TO UPPER 40S EAST IN THE CWA. BY SATURDAY...MUCH OF THE
SNOW COVER WILL BE DIMINISHED WITH HIGHS IN THE 50S AND 60S CWA
WIDE. IT WILL BE DRY THROUGH SATURDAY WITH VERY LITTLE IF ANY
CLOUD COVER.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
HIGH TEMPERATURE FORECASTING IS THE MAIN CHALLENGE THROUGH THE
EXTENDED PERIOD...AND DETERMINING JUST HOW WARM IT WILL GET AS
VERY MILD AIR MASS STREAMS ACROSS THE NORTHERN PLAINS. 850 MB AND
EVEN 925 MB TEMPS SOAR INTO THE TEENS ABOVE CELSIUS DURING SEVERAL
PERIODS FROM LATE THIS WEEKEND INTO THE MIDDLE OF NEXT WEEK. LATE
THIS WEEKEND INTO EARLY NEXT WEEK...PORTIONS OF THE NORTHEASTERN
CWA COULD STILL BE DEALING WITH SNOW COVER BUT EXPECT THIS TO BE
QUICKLY DIMINISHING THROUGH THE TIME PERIOD. MAY NEED TO TEMPER
READINGS ON SUNDAY ACROSS THE FAR NORTHEAST BUT WILL HAVE TO SEE
HOW SNOW COVER MELTS UNTIL THEN. 00Z GFS STILL SHOWING A COOLING
FRONTAL PASSAGE FOR TUESDAY WHICH WOULD KNOCK TEMPS BACK
SOME...BUT THIS HAS NO SUPPORT FROM 00Z RUNS OF THE EC OR CANADIAN
MODELS. FOR RIGHT NOW CURRENT FORECAST HIGHS ON TUESDAY ARE A FEW
TICKS LOWER THEN MONDAY...BUT STILL VERY MILD NONETHELESS WITH
READINGS IN THE 50S AND 60S. IN FACT...THE ENTIRE EXTENDED PERIOD
IS SHAPING UP VERY MILD WITH READINGS MOSTLY IN THE 50S AND
60S...POSSIBLY EVEN A FEW LOW 70S OVER THE SOUTHWEST CWA.
AS FOR PRECIPITATION...IT LOOKS DRY THROUGHOUT THE PERIOD AT THIS
TIME. WILL NEED TO WATCH A SHORTWAVE THAT TRAVELS NORTHWARD ACROSS
THE CENTRAL PLAINS MONDAY INTO MONDAY NIGHT. FOR THE MOST
PART...MODELS HAVE KEPT THIS SYSTEM TO THE EAST THE PAST COUPLE
DAYS. THE MOST RECENT RUNS OF THE EC AND CANADIAN NUDGE THIS BACK
WEST NOW AND BRING WESTERN EDGE OF PRECIP SHIELD NEAR I-29
CORRIDOR. GFS REMAINS FASTER AND FARTHER EAST WITH WAVE. SOMETHING
TO WATCH AS POPS MAY NEED TO BE ADDED TO THE FAR EASTERN COUNTIES
IF MODELS KEEP NUDGING THIS SYSTEM FURTHER WEST.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS EXPECTED THRU TAF PERIOD WITH SCT MID AND HIGH
LEVEL CLOUDS. SFC WINDS WILL INCREASE FROM WEST/NORTHWEST BY LATE
MORNING INTO THE 15 TO 25 KNOT RANGE. WINDS WILL SUBSIDE AROUND
SUNSET.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...MOHR
LONG TERM...TMT
AVIATION...DORN
WEATHER.GOV/ABERDEEN