Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/04/13
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
230 PM PDT THU MAY 2 2013
.SYNOPSIS...
A HIGH PRESSURE SYSTEM WITH GUSTY OFFSHORE WINDS WILL CAUSE WELL
ABOVE NORMAL TEMPERATURES THROUGH FRIDAY. THE HIGH WILL EXIT THE
REGION LATE FRIDAY AND TEMPERATURES WILL DROP ON SATURDAY. A LOW
PRESSURE SYSTEM WILL ARRIVE BY SUNDAY WITH POSSIBLE PRECIPITATION
THROUGH TUESDAY. THE TEMPERATURES WILL BE BELOW NORMAL INTO MIDWEEK.
&&
.SHORT TERM (TODAY-SUN)...THE SMOKE PLUME FROM THE SPRINGS FIRE IN
CAMARILLO IS EXPECTED TO CONTINUE A WEST NORTHWEST TRAJECTORY
OVERNIGHT AND POSSIBLY MOVE OVER THE COASTAL WATERS ALONG THE
CENTRAL COAST. LOW LEVEL CLOUD FIELD APPROACHING THE CENTRAL COAST
THIS AFTERNOON WILL LIKELY MOVE ASHORE THIS EVENING AND THEN SCOUR
OUT OR MOVE OFFSHORE OVERNIGHT AS THE NORTHEAST WINDS DEVELOP. THE
LATE MORNING TEMPERATURES WILL LIKELY BE THE HIGHEST FOR THE DAY
WITH BEACH LOCATIONS...LIKE PISMO BEACH...POSSIBLY REACHING THE
LOWER 80S. AND CENTRAL COAST INLAND AREAS WILL LIKELY CLIMB TO
RECORD HEAT FRIDAY AFTERNOON. PATCHY LOW LEVEL CLOUDS SOUTH OF THE
NORTHERN CHANNEL ISLANDS WILL CONTINUE TO APPROACH THE LA/VENTURA
COASTS THROUGH THIS AFTERNOON AND POSSIBLY MOVE INTO THE SANTA
MONICA BAY WITH DENSE FOG TONIGHT. OTHERWISE THE LATEST HRRR WAS
CONSISTENT WITH PREVIOUS RUNS AND ONSHORE WINDS WILL MOVE INTO THE
COASTAL VALLEYS WHILE THE STRONG NORTHEAST WINDS DIMINISH THROUGH
THE REMAINDER OF THIS AFTERNOON. THE NORTHEAST WINDS WILL LIKELY
PREVAIL INLAND OVERNIGHT AND AS THE SEABREEZE DISSIPATES THE
NORTHEAST WINDS WILL RETURN TO THE COAST. THE WINDS MAY STRENGTHEN
WITH GUSTS TO 45 MPH FRIDAY MORNING OVER THE HIGH COUNTRY WITH LOCAL
GUSTS TO 35 MPH IN THE INTERIOR COASTAL VALLEYS. A WIND ADVISORY MAY
BE ISSUED FOR THE HIGH COUNTRY FOLLOWING THE HIGH WIND WARNING
EXPIRATION AT 6 PM THIS EVENING. A COOLING TREND WILL OCCUR SATURDAY
THROUGH SUNDAY. ONSHORE WINDS WILL RETURN SATURDAY AND TEMPERATURES
WILL COOL THOUGH LIKELY REMAIN 5 TO 10 DEGREES ABOVE NORMAL SATURDAY
AND TO AT OR BELOW NORMAL SUNDAY. AN UPPER LEVEL LOW PRESSURE SYSTEM
CURRENTLY BETWEEN THE HAWAIIAN ISLANDS AND SOUTHERN CALIFORNIA WILL
APPROACH THROUGH SUNDAY. LATEST GUIDANCE DIFFERS FROM PREVIOUS RUNS
AND BETWEEN SUITES THOUGH SKIES WILL LIKELY BECOME CLOUDY AND A
CHANCE OF SHOWERS ARE EXPECTED SUNDAY.
.LONG TERM (MON-THU)...A STABLE TYPE PATTERN WITH A ANTICLONIC
CIRCULATION CENTERED OVER THE PAC NW AND CYCLONIC CIRCULATION OVER
THE SFO BAY AREA WILL DEVELOP SUNDAY AND PERSIST THROUGH WEDNESDAY.
ONE UPPER LEVEL TROUGH WILL ROTATE AND EXIT THROUGH THE SOLITON TYPE
FEATURE SUNDAY THROUGH MONDAY AND A SECOND ONE IS EXPECTED TUEDAY
NIGHT THROUGH WEDNESDAY. PARTLY TO MOSTLY CLOUDY SKIES ARE EXPECTED
WITH A SLIGHT CHANCE OF SHOWERS MONDAY THROUGH LATE TUESDAY EVENING.
TEMPERATURES WILL COOL THROUGH THE PERIOD AND LIKELY RANGE 4 TO 8
DEGREES BELOW SEASONAL NORMAL THROUGH THE PERIOD.
&&
.FIRE WEATHER...
RED FLAG WARNINGS IN EFFECT FOR MUCH OF LOS ANGELES AND VENTURA
COUNTIES THROUGH FRIDAY AS A MODERATE TO STRONG SANTA ANA WIND EVENT
AFFECTS SOUTHWEST CALIFORNIA. THE PEAK IN WIND SPEEDS IS OCCURRING
THIS MORNING...WITH GUSTS OF 65 TO 75 MPH OVER THE INTERIOR PEAKS OF
LA COUNTY...AND VALLEY LOCATIONS SEEING GUSTS OF 40 TO 60
MPH...STRONGEST IN THE SANTA CLARITA VALLEY AND THE EASTERN VENTURA
VALLEYS. GUSTS TO 45 MPH HAVE BEEN OBSERVED AS FAR WEST AS THE
VENTURA COUNTY COAST NEAR CAMARILLO. RELATIVE HUMIDITIES ARE VERY
LOW WITH MANY VALUES IN THE MID TO LOWER SINGLE DIGITS OBSERVED
ACROSS THE AREA. IN ADDITION...FUELS IN THE AREA ARE EXTREMELY DRY
FOR THIS TIME OF THE YEAR...AT VALUES THAT ARE MORE TYPICAL FOR MID
TO LATE SUMMERTIME. THE COMBINATION OF STRONG WIND GUSTS...LOW
HUMIDITIES AND VERY DRY FUELS HAS CREATED THE POTENTIAL FOR EXTREME
FIRE BEHAVIOR.
SURFACE PRESSURE GRADIENTS ARE BEGINNING TO EASE SLIGHTLY ACROSS
THE AREA...WHICH SHOULD ALLOW THE OFFSHORE WINDS TO BEGIN TO
DIMINISH ACROSS THE AREA BY EARLY THIS AFTERNOON. ALONG THE
IMMEDIATE COAST...ONSHORE WINDS HAVE BEEN OBSERVED IN SOME LOCATIONS
AND THERE IS A CHANCE THAT THE WEST TO SOUTHWEST FLOW WILL SPREAD
INLAND ACROSS THE COASTAL PLAIN OF LA AND VENTURA COUNTIES THIS
AFTERNOON INTO THIS EVENING. THE SOUTHWEST FLOW IS FORECAST BY THE
NAM12 MET GUIDANCE TO GUST UP TO AROUND 25 MPH. THE COASTAL WINDS
WILL SHIFT BACK TO OFFSHORE BY AROUND SUNRISE FRIDAY MORNING AND
INCREASE...BUT WITH LOWER SPEEDS THAN WHAT HAS BEEN OBSERVED TODAY.
HOWEVER...IN SPITE OF THE LOWER WINDS SPEEDS...VERY DRY CONDITIONS
AND EXTREME FIRE DANGER WILL CONTINUE THROUGH FRIDAY AFTERNOON.
HUMIDITY RECOVERIES OVERNIGHT WILL BE POOR IN MOST
AREAS...ESPECIALLY WHERE EXPOSED TO OFFSHORE WIND THROUGH THE NIGHT.
HUMIDITIES WILL FALL QUICKLY TO THE SINGLE DIGITS AGAIN FRIDAY
MORNING...WITH MINIMUM READINGS OF 5 PERCENT OR LOWER.
BY EARLY AFTERNOON A MORE WIDESPREAD WIND SHIFT TO THE SOUTHWEST TO
WEST IS EXPECTED. THIS WILL ALLOW HUMIDITIES TO BEGIN TO RISE ACROSS
A LARGER PORTION OF THE COASTAL PLAIN...AND THIS MAY ADVANCE INLAND
TO THE COASTAL VALLEYS OVERNIGHT.
.AVIATION...03/1745Z...
HIGH CONFIDENCE IN VFR CONDITIONS AT MOST SITES OVER THE NEXT 24
HOURS DUE TO THE ONGOING OFFSHORE EVENT. AN EXCEPTION THIS MORNING
IS OXR WHERE THE NORTHEAST WINDS ARE BLOWING SMOKE FROM A FIRE IN
CAMARILLO OVER THE AIRPORT. SOME OF THE GUIDANCE BRINGS MVFR
CONDITIONS INTO OXR AND LAX EARLY TOMORROW MORNING DUE TO BR OR
HZ...BUT THAT DOES NOT SEEM LIKELY WITH THE OFFSHORE FLOW.
KLAX...MODERATE-HIGH CONFIDENCE IN THE CURRENT TAF WITH VFR
CONDITIONS THRU FRIDAY MORNING. GUIDANCE BRINGS MVFR CONDITIONS IN
EARLY FRIDAY MORNING DUE TO BR AND HZ...BUT THAT DOES NOT SEEM
LIKELY WITH THE OFFSHORE FLOW.
KBUR...HIGH CONFIDENCE IN VFR CONDITIONS THRU FRIDAY MORNING. SOME
UNCERTAINTY IN WHETHER NORTHEAST WINDS WILL SURFACE THIS MORNING AND
EARLY THIS AFTERNOON.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING (SEE LAXNPWLOX).
RED FLAG WARNING (SEE LAXRFWLOX).
WIND ADVISORY (SEE LAXNPWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX).
&&
$$
PUBLIC...30
AVIATION...KJ
SYNOPSIS...SETO
FIRE...SMITH
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
802 PM EDT Fri May 3 2013
.SYNOPSIS...
The 20 UTC regional surface analysis showed a broad 1004mb low
near the east coast of central FL, with a trough extending
northwestward to the FL Panhandle coastal waters. A ridge remained
"wedged" down the Piedmont, and as has been the case since
yesterday, the enhanced pressure gradient between these features
was causing unusually strong east winds. Vapor imagery and upper
air data showed a cutoff low over AR, and a short wave trough off
the FL east coast. Like yesterday, our forecast area remains in
between two zones of deep layer moisture and lift, so the rain
we`ve been getting today has been generally light. A cold front
extended along the MS-AL state line into the central Gulf of
Mexico, and was slowly translating eastward. Fairly strong
frontogenetic forcing along and just behind this front was
producing deep moist convection, though not much lightning thus
far.
&&
.SHORT TERM [Tonight and Saturday]...
The latest NWP guidance consensus shows temporary decrease in
rain coverage overnight, with cloudy, breezy conditions and above-
average low temperatures (lower to mid 60s) except Southeast AL
and the FL Panhandle, where temperatures will be much cooler
behind the cold front (upper 40s to lower 50s around daybreak).
The global and regional models forecast a narrow band of strong
Q-G forcing along the frontogenetic band as it translates east
across our forecast area Saturday, but their derived MOS PoPs are
not particularly high. We prefer the Convection Allowing Models
and derived downscaled NAM PoPs, giving our region a PoP ranging
from 50% at the coast to 90% north of Dothan and Albany. The MOS
temperatures appear too warm and "diurnal" given the expected
cloud cover and rainy conditions behind the cold front, so we
blended in the output from the CAM and downscaled NAM as well,
which tend to do reasonably well when insolation is greatly
reduced and the there is strong boundary layer mixing (like we
expect Saturday behind the front). There could even be a few
thunderstorms Saturday afternoon in the FL Big Bend and south
central GA, where the SBCAPE values may reach the 500-1500 J/KG
range just before the cold front passes.
It will feel quite chilly across much of our forecast area
Saturday, especially for May. Highs at many sites will occur in
the morning, with near-steady temperatures after the cold front
passes. The combination of clouds, north winds around 10 MPH, and
occasional rain will make it feel quite "raw".
&&
.AVIATION [through 00 UTC Sunday]...
There is some disagreement among the NWP guidance overnight and
early Saturday, with the GFS/NAM MOS forecasting IFR-LIFR cigs while the
SREF and HRRR forecast MVFR-VFR cigs. We blended these solutions
(as well as persistence) and are forecasting generally low-end
MVFR cigs overnight, except IFR at KDHN since that terminal was
already IFR. Although there will be occasional light rain
overnight, a round of heavier rain (with vis reduced to MVFR) is
likely Saturday as a cold front moves slowly east across the
region. Some improvement in cigs, along with an end of the rain,
is likely late Saturday.
&&
.HYDROLOGY...
Still only anticipated maximum areal rainfall amounts of 1 to 1.5
inches across the region through Sunday, which is only likely to
elevate stream flows to near action level.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 63 66 47 77 / 30 60 20 20
Panama City 59 63 53 73 / 40 50 10 20
Dothan 54 59 44 71 / 50 80 20 30
Albany 61 64 48 75 / 50 80 50 20
Valdosta 62 68 51 77 / 40 70 50 10
Cross City 63 74 54 79 / 40 50 30 10
Apalachicola 65 67 52 74 / 30 40 10 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
GA...NONE.
FL...NONE.
GM...NONE.
&&
$$
HYDROLOGY...Godsey
REST OF DISCUSSION...Fournier
AREA FORECAST DISCUSSION
NWS MIAMI FL
501 PM EDT THU MAY 2 2013
.UPDATE...
A SMALL CRAFT ADVISORY IS IN EFFECT FROM 2 AM THIS MORNING TO 200
PM FRIDAY FOR THE ATLANTIC WATERS TO THE EAST OF PALM BEACH COUNTY. THE
COMBINATION OF WINDS FORECAST TO INCREASE TO THE 16 TO 21 KNOT
RANGE AND A SMALL LONG PERIOD SWELL WILL RESULT IN SEAS TO NEAR 7
FEET MAINLY EXPECTED TO THE EAST OF PALM BEACH COUNTY.
60
&&
.PREV DISCUSSION... /ISSUED 324 PM EDT THU MAY 2 2013/
DISCUSSION...
WIDESPREAD SHOWERS AND THUNDERSTORMS HAVE MOVED ACROSS SOUTH
FLORIDA TODAY. A WELL DEVELOPED MCS/MCV WAS MOVING ACROSS SOUTH
FLORIDA THIS AFTERNOON...AND SOME STORMS HAVE SHOWN ROTATION.
THERE WERE REPORTS OF DAMAGE FROM A STORM IN BOCA RATON EARLIER
THIS AFTERNOON AS WELL. SEVERE STREET FLOODING WAS REPORTED IN THE
BOCA RATON AND DELRAY BEACH AREAS...WHERE OVER 7.5 INCHES OF RAIN
HAS FALLEN.
A SURFACE BOUNDARY APPEARED TO BE DRIFTING SOUTH AND IT WAS
LOCATED ACROSS BROWARD COUNTY THIS AFTERNOON...AND LOCALLY HEAVY
RAIN AND FLOODING WILL BE POSSIBLE ACROSS BROWARD AND MIAMI DADE
COUNTY THROUGH THIS EVENING. AN UPPER LEVEL LOW ACROSS THE
NORTHEASTERN GULF WILL CONTINUE TO SLIDE SOUTHEAST AND OPEN INTO A
TROUGH OVERNIGHT AS IT MOVES INTO THE FLORIDA PENINSULA. UPPER
LEVEL DIVERGENCE FROM THIS UPPER LOW MAY HELP STORMS CONTINUE INTO
THE EVENING BEFORE DIMINISHING. THE HRRR SHOWS SHOWERS
DISSIPATING AFTER 00Z THIS EVENING.
SURFACE LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS THE EASTERN
GULF OF MEXICO AND MOVE OVER SOUTH FLORIDA ON FRIDAY. THIS
WILL ALLOW THE STEERING FLOW OVER SOUTH FLORIDA TO REMAIN LIGHT
FROM A SOUTH TO SOUTHWEST DIRECTION KEEPING THE DEEP TROPICAL
MOISTURE IN PLACE. SO SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED ACROSS THE REGION AGAIN ON FRIDAY. THE
EMPHASIS WILL BE FOR THE EAST COAST AND NORTHEAST COAST WHERE THE
BEST LOW LEVEL CONVERGENCE AND THE SURFACE BOUNDARY WILL BE
FOUND...ALONG WITH UPPER LEVEL FORCING ASSOCIATED WITH THE UPPER
LEVEL FLOW.
THE 500 MB TEMPS ON FRIDAY SHOULD BE A LITTLE BIT WARMER THAN
TODAY...DUE TO THE UPPER LEVEL LOW DISSIPATING OVER THE NORTHEAST
GULF OF MEXICO. HOWEVER...ANY STORMS THAT DO AFFECT SOUTH FLORIDA
TONIGHT INTO FRIDAY WILL BE CAPABLE OF PRODUCING HEAVY RAINFALL.
THE LOW WILL CONTINUE TO MOVE EAST OVER SOUTH FLORIDA ON SATURDAY
BEFORE MOVING INTO THE WESTERN ATLANTIC WATERS ON SUNDAY. SLIGHTLY
DRIER CONDITIONS ARE EXPECTED ON SATURDAY...BUT RAIN CHANCES WILL
CONTINUE FOR THE NORTHERN TWO-THIRDS OF THE REGION. MUCH DRIER
AIR WILL WORK INTO THE AREA FROM THE WEST ON SUNDAY.
FOR EARLY TO MIDDLE OF NEXT WEEK...A MID TO UPPER LEVEL LOW WILL
DEVELOP OVER THE TENNESSEE VALLEY AND MOVE SLOWLY EAST TOWARDS THE
MID ATLANTIC STATES. THIS WILL ALLOW FOR DRIER WEATHER TO CONTINUE
TO WORK INTO SOUTH FLORIDA FROM THE WEST. SO THE WEATHER SHOULD
REMAIN DRY OVER SOUTH FLORIDA FOR THE EARLY TO MIDDLE PART OF NEXT
WEEK.
AVIATION...
LIGHT TO MODERATE RAIN WILL CONTINUE AT KAPF AND KPBI THROUGH
ABOUT 21-22Z. VERY HEAVY RAIN AND THUNDERSTORMS WILL CONTINUE FOR
THE REST OF THE EAST COAST TAF SITES...WHERE IFR CONDITIONS MAY
OCCUR. RAIN IS EXPECTED TO BEGIN DIMINISHING AFTER 04-06Z
TONIGHT...WITH IMPROVING CONDITIONS. STORMS WILL BE POSSIBLE AGAIN
BEGINNING LATE MORNING ON FRIDAY. WINDS WILL BE VARIABLE THE REST
OF THIS AFTERNOON WITH GUSTY WINDS POSSIBLE. LIGHT AND VARIABLE
WINDS ARE EXPECTED AFTER MIDNIGHT. WITH LOW PRESSURE MOVING OVER
SOUTH FLORIDA...WESTERLY WINDS ARE EXPECTED ON FRIDAY.
MARINE...
THE WINDS OVER SOUTH FLORIDA TODAY INTO FRIDAY WILL BE FROM THE
SOUTH TO SOUTHEAST DIRECTION AT 10 KNOTS OR LESS...BEFORE SLOWLY
SWINGING TO A NORTHWEST DIRECTION BY LATE THIS WEEKEND AND
INCREASING SPEEDS TO 10 TO 15 KNOTS. AT THE SAME TIME...A SMALL
NORTHEAST SWELL OF 1 TO 3 FEET WILL CONTINUE TO AFFECT THE
ATLANTIC WATERS OF SOUTH FLORIDA LATE THIS WEEK INTO THIS
WEEKEND. THESE CONDITIONS WILL ALLOW FOR THE ATLANTIC SEAS TO
REMAIN BELOW 6 FEET TODAY INTO THIS WEEKEND...EXCEPT FOR THE PALM
BEACH WATERS WHERE THE SEAS COULD BUILD TO 6 FEET THIS WEEKEND.
FOR THE GULF SIDE...THE SEAS WILL REMAIN BELOW 6 FEET TODAY INTO
THIS WEEKEND. THE ONLY EXCEPTION IS THE OFFSHORE GULF WATERS WHERE
THE SEAS COULD BUILD TO 6 FEET BY THIS WEEKEND.
FIRE WEATHER...
DEEP TROPICAL MOISTURE WILL REMAIN OVER THE REGION ON FRIDAY WITH
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. SLIGHTLY DRIER
AIR WILL BEGIN TO MOVE INTO THE REGION ON SATURDAY...WITH LESSER
RAIN CHANCES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 70 83 69 87 / 80 70 40 30
FORT LAUDERDALE 72 83 73 88 / 80 60 30 20
MIAMI 72 84 72 87 / 80 60 30 10
NAPLES 67 83 68 87 / 40 50 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 AM TO 2 PM EDT
FRIDAY FOR COASTAL WATERS FROM JUPITER INLET TO DEERFIELD
BEACH, FL OUT 20 NM-WATERS FROM JUPITER INLET TO DEERFIELD
BEACH, FL EXTENDING FROM 20 NM TO 60 NM.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...60/BD
AVIATION/RADAR...59/RM
AREA FORECAST DISCUSSION
NWS MIAMI FL
324 PM EDT THU MAY 2 2013
.DISCUSSION...
WIDESPREAD SHOWERS AND THUNDERSTORMS HAVE MOVED ACROSS SOUTH
FLORIDA TODAY. A WELL DEVELOPED MCS/MCV WAS MOVING ACROSS SOUTH
FLORIDA THIS AFTERNOON...AND SOME STORMS HAVE SHOWN ROTATION.
THERE WERE REPORTS OF DAMAGE FROM A STORM IN BOCA RATON EARLIER
THIS AFTERNOON AS WELL. SEVERE STREET FLOODING WAS REPORTED IN THE
BOCA RATON AND DELRAY BEACH AREAS...WHERE OVER 7.5 INCHES OF RAIN
HAS FALLEN.
A SURFACE BOUNDARY APPEARED TO BE DRIFTING SOUTH AND IT WAS
LOCATED ACROSS BROWARD COUNTY THIS AFTERNOON...AND LOCALLY HEAVY
RAIN AND FLOODING WILL BE POSSIBLE ACROSS BROWARD AND MIAMI DADE
COUNTY THROUGH THIS EVENING. AN UPPER LEVEL LOW ACROSS THE
NORTHEASTERN GULF WILL CONTINUE TO SLIDE SOUTHEAST AND OPEN INTO A
TROUGH OVERNIGHT AS IT MOVES INTO THE FLORIDA PENINSULA. UPPER
LEVEL DIVERGENCE FROM THIS UPPER LOW MAY HELP STORMS CONTINUE INTO
THE EVENING BEFORE DIMINISHING. THE HRRR SHOWS SHOWERS
DISSIPATING AFTER 00Z THIS EVENING.
SURFACE LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS THE EASTERN
GULF OF MEXICO AND MOVE OVER SOUTH FLORIDA ON FRIDAY. THIS
WILL ALLOW THE STEERING FLOW OVER SOUTH FLORIDA TO REMAIN LIGHT
FROM A SOUTH TO SOUTHWEST DIRECTION KEEPING THE DEEP TROPICAL
MOISTURE IN PLACE. SO SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED ACROSS THE REGION AGAIN ON FRIDAY. THE
EMPHASIS WILL BE FOR THE EAST COAST AND NORTHEAST COAST WHERE THE
BEST LOW LEVEL CONVERGENCE AND THE SURFACE BOUNDARY WILL BE
FOUND...ALONG WITH UPPER LEVEL FORCING ASSOCIATED WITH THE UPPER
LEVEL FLOW.
THE 500 MB TEMPS ON FRIDAY SHOULD BE A LITTLE BIT WARMER THAN
TODAY...DUE TO THE UPPER LEVEL LOW DISSIPATING OVER THE NORTHEAST
GULF OF MEXICO. HOWEVER...ANY STORMS THAT DO AFFECT SOUTH FLORIDA
TONIGHT INTO FRIDAY WILL BE CAPABLE OF PRODUCING HEAVY RAINFALL.
THE LOW WILL CONTINUE TO MOVE EAST OVER SOUTH FLORIDA ON SATURDAY
BEFORE MOVING INTO THE WESTERN ATLANTIC WATERS ON SUNDAY. SLIGHTLY
DRIER CONDITIONS ARE EXPECTED ON SATURDAY...BUT RAIN CHANCES WILL
CONTINUE FOR THE NORTHERN TWO-THIRDS OF THE REGION. MUCH DRIER
AIR WILL WORK INTO THE AREA FROM THE WEST ON SUNDAY.
FOR EARLY TO MIDDLE OF NEXT WEEK...A MID TO UPPER LEVEL LOW WILL
DEVELOP OVER THE TENNESSEE VALLEY AND MOVE SLOWLY EAST TOWARDS THE
MID ATLANTIC STATES. THIS WILL ALLOW FOR DRIER WEATHER TO CONTINUE
TO WORK INTO SOUTH FLORIDA FROM THE WEST. SO THE WEATHER SHOULD
REMAIN DRY OVER SOUTH FLORIDA FOR THE EARLY TO MIDDLE PART OF NEXT
WEEK.
&&
.AVIATION...
LIGHT TO MODERATE RAIN WILL CONTINUE AT KAPF AND KPBI THROUGH
ABOUT 21-22Z. VERY HEAVY RAIN AND THUNDERSTORMS WILL CONTINUE FOR
THE REST OF THE EAST COAST TAF SITES...WHERE IFR CONDITIONS MAY
OCCUR. RAIN IS EXPECTED TO BEGIN DIMINISHING AFTER 04-06Z
TONIGHT...WITH IMPROVING CONDITIONS. STORMS WILL BE POSSIBLE AGAIN
BEGINNING LATE MORNING ON FRIDAY. WINDS WILL BE VARIABLE THE REST
OF THIS AFTERNOON WITH GUSTY WINDS POSSIBLE. LIGHT AND VARIABLE
WINDS ARE EXPECTED AFTER MIDNIGHT. WITH LOW PRESSURE MOVING OVER
SOUTH FLORIDA...WESTERLY WINDS ARE EXPECTED ON FRIDAY.
&&
.MARINE...
THE WINDS OVER SOUTH FLORIDA TODAY INTO FRIDAY WILL BE FROM THE
SOUTH TO SOUTHEAST DIRECTION AT 10 KNOTS OR LESS...BEFORE SLOWLY
SWINGING TO A NORTHWEST DIRECTION BY LATE THIS WEEKEND AND
INCREASING SPEEDS TO 10 TO 15 KNOTS. AT THE SAME TIME...A SMALL
NORTHEAST SWELL OF 1 TO 3 FEET WILL CONTINUE TO AFFECT THE
ATLANTIC WATERS OF SOUTH FLORIDA LATE THIS WEEK INTO THIS
WEEKEND. THESE CONDITIONS WILL ALLOW FOR THE ATLANTIC SEAS TO
REMAIN BELOW 6 FEET TODAY INTO THIS WEEKEND...EXCEPT FOR THE PALM
BEACH WATERS WHERE THE SEAS COULD BUILD TO 6 FEET THIS WEEKEND.
FOR THE GULF SIDE...THE SEAS WILL REMAIN BELOW 6 FEET TODAY INTO
THIS WEEKEND. THE ONLY EXCEPTION IS THE OFFSHORE GULF WATERS WHERE
THE SEAS COULD BUILD TO 6 FEET BY THIS WEEKEND.
&&
.FIRE WEATHER...
DEEP TROPICAL MOISTURE WILL REMAIN OVER THE REGION ON FRIDAY WITH
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. SLIGHTLY DRIER
AIR WILL BEGIN TO MOVE INTO THE REGION ON SATURDAY...WITH LESSER
RAIN CHANCES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 70 83 69 87 / 80 70 40 30
FORT LAUDERDALE 72 83 73 88 / 80 60 30 20
MIAMI 72 84 72 87 / 80 60 30 10
NAPLES 67 83 68 87 / 40 50 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...23/SK
AREA FORECAST DISCUSSION
NWS MIAMI FL
159 AM EDT THU MAY 2 2013
.AVIATION...
A TROUGH OF LOW PRESSURE ACROSS THE REGION WILL CONTINUE TO BRING
SHOWER AND/OR THUNDERSTORMS MAINLY FROM LATE THIS MORNING AND INTO THE
EVENING HOURS OF THURSDAY. THERE IS A CHANCE OF AN EARLIER START
BASED ON CURRENT TRENDS WITH ACTIVITY ACROSS THE KEYS POTENTIALLY
PROPAGATING NORTH INTO THE REGION TOWARDS SUNRISE SO WILL BE
MONITORING THAT. THIS MEANS THAT ALTHOUGH VFR TO MVFR (FOR CEILINGS)
CONDITIONS ARE EXPECTED TO PREVAIL OVER THE NEXT 24 HOURS OR SO
AT THE TAF SITES, PERIODS WITH MIXED MVFR AND MAY BE EVEN IFR ARE
POSSIBLE WITH ANY STORMS AFFECTING THE TERMINALS, AND IN PARTICULAR
THE EAST COAST TERMINALS FROM AROUND NOON AND INTO THE EVENING
HOURS WITH THE CAVEAT MENTIONED EARLIER. ALSO PERIODS OF MVFR OR
EVEN IFR CEILINGS CANNOT BE RULED OUT EARLY THIS MORNING WITH LOW
STRATUS CLOUDS AT ANY OF THE TERMINALS. BUT GIVEN UNCERTAINTY WILL
HANDLE THOSE WITH AMENDMENTS AS NEEDED.
WINDS WILL REMAIN LIGHT FROM THE EAST OR VARIABLE THIS MORNING
BECOMING SE 8-13 KTS TODAY WITH A SSW SEA BREEZE DURING THE
AFTERNOON POSSIBLE AT APF. WINDS WILL BECOME LIGHT GENERALLY FROM
THE SE ONCE AGAIN TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 827 PM EDT WED MAY 1 2013/
UPDATE...
CHANCES FOR SHOWERS AND POSSIBLY A FEW THUNDERSTORMS WILL PREVAIL
THROUGH THE NIGHT AS WEAKNESSES IN THE MID LEVEL FLOW CONTINUE TO
PUSH ACROSS THE AREA. LATEST IR SATELLITE IMAGERY SHOWS AN MCS
SITUATED ACROSS THE SOUTH CENTRAL GULF OF MEXICO MOVING SOUTH
TOWARD THE YUCATAN CHANNEL. LATEST SHORT TERM MODELS INCLUDING
LOCAL MODEL DATA DEPICTS A FEW ASSOCIATED SHOWERS AND
THUNDERSTORMS PUSHING EAST AND INTO THE EASTERN GULF WATERS BY
EARLY TOMORROW MORNING. KEPT CHANCE POP ACROSS THE ENTIRE AREA
THROUGH THE MORNING HOURS. UPDATE WILL BE SENT SHORTLY.
PREV DISCUSSION... /ISSUED 744 PM EDT WED MAY 1 2013/
AVIATION...
A TROUGH OF LOW PRESSURE THAT BROUGHT SHOWERS AND THUNDERSTORMS
TODAY, WILL CONTINUE TO BRING SOME SHOWER ACTIVITY INTO THE LATE
EVENING HOURS. THIS MEAN VFR TO MVFR CONDITIONS ARE EXPECTED
OVERNIGHT, WITH VFR IN THE MORNING, RETURNING TO A MIX OF VFR AND
MVFR TOMORROW. THIS IS DUE TO ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS EXPECTED TO DEVELOP AROUND MID DAY. WINDS WILL BE
LIGHT AND VARIABLE FOR A WHILE THIS EVENING, BEFORE BECOMING
EASTERLY BETWEEN 5 AND 10 KTS. THEY WILL INCREASE TO 10 TO 15 KTS
TOMORROW MORNING.
PREV DISCUSSION... /ISSUED 238 PM EDT WED MAY 1 2013/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
LARGE CUT-OFF MID LEVEL LOW CONTINUES TO SLOWLY DRIFT EAST ACROSS
THE SOUTH CENTRAL GULF STATES. A LARGE CLUSTER OF CONVECTION
DEVELOPED ON THE SOUTHERN FRINGES OF THIS LOW AND HAS MOVED EAST
THROUGH EARLY THIS AFTERNOON AND AS OF 1830Z WAS MOVING ACROSS THE
INTERIOR AND TOWARDS THE EAST COAST METRO AREA. ANOTHER CLUSTER OF
CONVECTION IS ALSO CURRENTLY DEVELOPING OVER THE CENTRAL GULF WITH
THE HRRR SHOWING THIS MOVING ACROSS SOUTH FLORIDA THIS EVENING SO
HAVE INCREASED THE POPS FOR THE OVERNIGHT HOURS. AT THE SAME TIME, A
DEEPENING TROUGH INTO THE CENTRAL PLAINS STATES ON THURSDAY WILL
CONTINUE TO DEEPEN AND CUT OFF OVER THE MISSISSIPPI VALLEY WITH
THE SOUTHERN CUT-OFF LOW BECOMING PHASED IN WITH THIS LOW. THIS
KEEPS SOUTH FLORIDA IN RICH TROPICAL FLOW OF AIR THROUGH THE END
OF THE WEEK WITH HIGH CHANCES FOR SHOWERS AND THUNDERSTORMS.
FORECAST SOUNDINGS THROUGH THIS PERIOD LOOK QUITE SIMILAR WITH
PWAT REMAINING WELL ABOVE NORMAL FOR EARLY MAY AND A WEAK WESTERLY
STEERING FLOW. GLOBAL MODELS ARE NOW MORE IN AGREEMENT WITH THE
OVERALL SOLUTION DURING THE NEXT 48 HOURS AND SHOW THE LOW
DRIFTING TO THE SOUTHEAST BEFORE GETTING PHASED IN WITH THE
UPSTREAM DEEPENING TROUGH. THIS ON THURSDAY AND POSSIBLY FRIDAY
WILL DESTABILIZE THE ATMOSPHERE WITH COOLING 500 MB TEMPERATURES.
THE 12Z MFL SOUNDING SHOWED A TEMPERATURE OF -10 CELSIUS AND THE
GFS SHOWS COOLING TO AROUND -12 ON THURSDAY INTO FRIDAY. SO THE
CONTINUED THREAT FOR STRONG STORMS WILL ALSO BE A FACTOR. OF
COURSE THERE WILL ALWAYS BE SOME DAY TO DAY FLUCTUATIONS WITH WEAK
DISTURBANCES MOVING THROUGH THE BASE OF THE TROUGH.
LONG TERM (SATURDAY THROUGH WEDNESDAY)...
THE EXTENDED PORTION OF THE FORECAST CONTINUES TO BE HIGHLY
UNCERTAIN WITH THE GFS AND ECMWF HAVING TWO DIFFERENT SOLUTIONS TO
THE DEEPENING TROUGH. BOTH CUT THIS LOW OFF FROM THE NORTHERN
LATITUDE FLOW AS MENTIONED ABOVE. THE GFS THEN DEVELOPS A MASSIVE
CUT-OFF LOW AND THEN SLOWLY DRIFTS IT TO THE EAST THROUGH THE MIDDLE
OF NEXT WEEK. THIS WOULD TEND TO DRAW A DRIER AIR MASS ACROSS SOUTH
FLORIDA FOR LESSER STORM ACTIVITY. HOWEVER, THE ECMWF SPLITS THE
CUT-OFF LOW DRIFTING THE SOUTHERN PORTION TO THE SOUTH WHICH WOULD
KEEP SOUTH FLORIDA VERY UNSTABLE. FOR NOW, WILL GO WITH THE GFS
SOLUTION AS THIS MODEL HAS BEEN THE MOST CONSISTENT IN ITS FORECAST
WHERE THE ECMWF HAS HAD DIFFERENT SOLUTIONS WITH EACH RUN.
MARINE...
TRANQUIL CONDITIONS OUTSIDE OF ISOLATED STRONG CONVECTION WILL
CONTINUE THROUGH THURSDAY. SOME INCREASE IN A NORTHEAST SWELL IS
EXPECTED LATE IN THE WEEK INTO THE WEEKEND WITH POSSIBLE SEAS
BUILDING TO 7 FEET OVER THE PALM BEACH WATERS.
FIRE WEATHER...
NO PROBLEMS OR CONCERNS WITH DEEP TROPICAL MOISTURE REMAINING IN PLACE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 70 81 71 / 70 50 60 50
FORT LAUDERDALE 81 71 82 73 / 70 50 60 50
MIAMI 81 71 83 73 / 70 50 60 40
NAPLES 85 67 83 67 / 50 40 50 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...54/BNB
AVIATION/RADAR...52/PS
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
458 AM EDT THU MAY 2 2013
.SYNOPSIS...
HIGH PRESSURE WILL GRADUALLY WEAKEN AND RETREAT INTO THE ATLANTIC
THROUGH THE WEEKEND...AND DEEP LOW PRESSURE WILL SLOWLY ROLL FROM
THE GREAT PLAINS ACROSS THE SOUTHEAST THROUGH THE MIDDLE OF NEXT
WEEK. THIS LOW PRESSURE WILL PUSH A COLD FRONT THROUGH THE AREA LATE
THIS WEEKEND OR EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PRE-DAWN...DEEP LAYERED MOISTURE ADVECTION HAS NUDGED A BIT FURTHER
N THIS MORNING WITH PWATS OBSERVED BY THE LATEST RAP MODEL OUTPUT RIGHT
BETWEEN THE GFS AND NAM AT 06Z- 08Z. THE LOW LEVEL MOIST LAYER ALONG
THE GEORGIA COAST WAS ENOUGH TO SUPPORT AREAS OF LIGHT RAIN WITHIN
A REGION OF ISENTROPIC ASCENT AND LOW LEVEL SPEED CONVERGENCE. WE
HAVE BUMPED UP POPS TO ACCOUNT FOR RADAR TRENDS. OTHERWISE...CLOUDS
REMAIN PREVALENT OVER OUR REGION WITH TEMPS IN THE MID 60S MOST
AREAS. NE WINDS WERE PICKING UP...MOST NOTICEABLE ALONG THE
COAST... ALREADY BLOWING 20-25 MPH WITH HIGHER GUSTS FROM PULASKI
TO SAPELO.
BLOCKING UPPER RIDGE EXTENDS FROM SE CANADA DOWN INTO THE CAROLINAS
TODAY KEEPING THE UPPER CUT-OFF LOW PRES OVER THE GULF COAST REGION
FROM ADVANCING TO THE NE TODAY. THIS LOW WILL TEND TO ADVANCE
IT/S WAY AROUND THE SOUTHERN PERIPHERY OF THE UPPER RIDGE AND THIS
TREND IN GOOD AGREEMENT ON THE 00Z MODEL RUN. THE MOST SIGNIFICANT
CHANGES WE HAVE MADE TODAY IS INCREASING CHANCES FOR WET WEATHER
ALONG AND TO THE S OF I-16. IF RADAR TRENDS CONTINUE TO DICTATE WE
MAY NEED TO INCREASE POPS FURTHER S OF A LINE FROM METTER TO
SAVANNAH...AND PARTICULARLY CLOSER TO THE ALTAMAHA RIVER AREA. A
DEEP MOISTURE GRADIENT EXTENDS THROUGH THIS REGION AND THESE
GEORGIA ZONES ARE RIGHT ALONG IT...MAKING POPS PROBLEMATIC SINCE
THERE COULD BE A FINE LINE BETWEEN A VERY WET DAY AND NO RAIN AT
ALL.
STRONG SURFACE HIGH PRES WEDGING DOWN THE LEE OF THE MOUNTAINS WILL
REMAIN ANCHORED TODAY AND WHEN SECONDARY LOW PRES IN THE BOUNDARY
LAYER BEGINS TO DEVELOP ACROSS CENTRAL FLORIDA LATER ON...WINDS
WILL BE QUITE STRONG AND GUSTY ALONG THE COAST. DEPENDENT ON THE
AMOUNT OF MESOSCALE PINCHING OF THE GRADIENT...WE COULD SEE SPEEDS
APPROACHING WIND ADVISORY CRITERIA FOR PARTS OF THE COAST FROM
BEAUFORT DOWN TO CHATHAM INTO MCINTOSH COUNTIES TODAY. ON AVERAGE
THE ONSHORE FLOW WILL BE IN THE 20-30 MPH RANGE WITH HIGHER GUSTS
TO THE E OF I-95 AND ESPECIALLY TO THE S OF EDISTO.
CLOUDS WILL PREVAIL BUT NAM/CMC OUTPUT SUGGESTS A BIT OF DRYING
COULD BRIEFLY SCATTER OUT LOWER CLOUDS IN THE CHARLESTON TRI-
COUNTY AREA LATE TODAY...WE HAVE NOT DEVIATED FROM MOSTLY CLOUDY N
TO CLOUDY S TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
THE DEEP MOISTURE GRADIENT DOES NOT MOVE MUCH TONIGHT WITH SOGGY
WEATHER CONTINUING JUST S OF THE ALTAMAHA REGION AND WE HAVE
MAINTAINED CHANCE POPS TO THE S OF I-16 BUT CONFIDENCE IS IFFY
ON HOW FAR N TO MAINTAIN ANY HIGHER POPS. BREEZY TO WINDY COASTAL
CONDITIONS WILL PERSIST AS WILL THE CLOUDS. LOW TEMPS AROUND 60 N
TO THE MID 60S COAST AND SOUTH.
AS AN IMPRESSIVE UPPER LOW DEEPENS/AMPLIFIES OVER THE CENTRAL
CONUS...THE UPPER LOW OVER THE NORTHERN GULF OF MEXICO/LOWER
MISSISSIPPI RIVER VALLEY WILL ADVANCE EAST AND OPEN TO A NEGATIVELY
TILTED UPPER TROUGH. AS THE BLOCKING HIGH TO THE NORTH BEGINS TO
WEAK AND SHIFT EAST...THIS ELONGATING UPPER TROUGH AND ASSOCIATED
BAND OF ENHANCED MOISTURE WILL GRADUALLY ADVANCE INTO THE REGION
FROM S/SW TO N/NE FRIDAY THROUGH SUNDAY...AND POPS SHOULD GENERALLY
INCREASE. DUE TO UNCERTAINTY REGARDING THE RATE OF RETREAT OF THE
BLOCKING HIGH AND ASSOCIATED RESISTANCE TO THE ADVANCE OF THE UPPER
TROUGH/MOISTURE...POPS DO NOT EXCEED 50 PERCENT FRIDAY AND SATURDAY.
HOWEVER...THESE POPS AND ASSOCIATED QPF COULD PROVE CONSERVATIVE...
ESPECIALLY IF PRECIPITATION COVERAGE EXPANDS IN RESPONSE TO DIURNAL
WARMING EACH DAY. THUS...HIGHER POPS/GREATER QPF COULD EVENTUALLY BE
REQUIRED...ESPECIALLY WITHIN NEAR TERM FORECASTS/UPDATES.
MEANWHILE...MODELS HAVE CLEARLY TRENDED TOWARD A SCENARIO FEATURING
THE MASSIVE UPPER LOW ROLLING EAST FROM THE PLAINS TOWARD THE EAST
COAST FRIDAY THROUGH SUNDAY. MODEL DEPICTION OF THE INTENSITY AND
TRACK OF THE UPPER LOW/ASSOCIATED COLD POOL DIFFERS AND THUS
DEGRADES FORECAST CONFIDENCE. OF PARTICULAR INTEREST...THE 02/00Z
EUROPEAN MODEL TRENDED TO A DEEPER UPPER LOW TRACKING FARTHER SOUTH
AND FASTER AS COMPARED TO EARLIER RUNS. IN THIS SCENARIO...THE UPPER
LOW WILL PUSH A COLD/OCCLUDED FRONT...PERHAPS EVEN A TRIPLE POINT
SURFACE LOW...INTO THE REGION AS EARLY AS SUNDAY AFTERNOON/
EVENING...ENHANCING THE POTENTIAL FOR PRECIPITATION INCLUDING
THUNDERSTORMS AND PERHAPS EVEN SUPPORTING SOME SEVERE WEATHER IF THE
UPPER COLD POOL/ASSOCIATED STEEPENING LAPSE RATES BEGIN TO
OVERSPREAD THE REGION. AS ALREADY MENTIONED...DUE TO FORECAST
UNCERTAINTY ARISING FROM MODEL DIFFERENCES AND LESS THAN IDEAL RUN
TO RUN MODEL CONSISTENCY...ADDED A MENTION OF THUNDER BUT ONLY
INDICATED CHANCE POPS SUNDAY.
STRONG/GUSTY ONSHORE WINDS WILL CONTINUE FRIDAY AND SATURDAY...THEN
WINDS SHOULD BEGIN TO SLACKEN SUNDAY. BELOW NORMAL TEMPERATURES...
INCLUDING HIGH TEMPERATURES IN THE 70S...WILL PREVAIL THROUGH THE
PERIOD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE DEEP UPPER LOW WILL CONTINUE TO ROLL EAST ACROSS THE REGION
THROUGH THE FIRST HALF OF NEXT WEEK AND SHOULD FINALLY SWING
NORTHEAST OF THE REGION BY THE END OF THE FORECAST PERIOD. SLOWER
MODEL SOLUTIONS DEPICT THE UPPER LOW PUSHING A COLD/OCCLUDED FRONT
THROUGH THE REGION AS LATE AS MONDAY...DELAYED FROM THE SUNDAY FROPA
DEPICTED BY THE 02/00Z EUROPEAN. THEN...THE REGION WILL REMAIN WITH
A DEEP LAYER CYCLONIC FLOW REGIME THROUGH MIDWEEK. OF SPECIAL
INTEREST...AN UNSEASONABLY INTENSE COLD POOL ALOFT...FEATURING
500 MB TEMPERATURES AS COLD AS -18C TO -23C...COLDEST ACROSS
NORTHERN COUNTIES...AND THE POTENTIAL FOR MESOSCALE BOUNDARIES/
CONVERGENCE WITHIN THE LOW LEVEL CYCLONIC FLOW REGIME COULD SUPPORT
DIURNAL THUNDERSTORMS AND AN ENHANCED THREAT FOR LARGE HAIL. POPS
COULD BELOW NORMAL TEMPERATURES ARE LIKELY TO PREVAIL THROUGH
MIDWEEK.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
EXPECT SUB-VFR CONDITIONS INTO LATE MORNING AND POSSIBLY INTO THIS
AFTERNOON AT KSAV. LATEST MODEL SOUNDINGS INDICATE A BIT OF A DRIER
PUNCH IN THE CLOUD LAYER RH FIELDS TO LIFT CIGS TO ABOVE 3 FT AT
KCHS THIS AFTERNOON BUT KSAV IS RIGHT ON A STRONG DEEPER LAYERED
MOISTURE GRADIENT AND THE FORECAST FOR CIG HEIGHTS REMAINS TRICKY.
WE WILL CARRY VCSH AT KSAV UNTIL RADAR TRENDS DICTATE. WE HAVE
RAMPED ONSHORE SURFACE WINDS UP TO 20G27 KT AT KSAV AS A WINDY
DAY IS ON TAP.
EXTENDED AVIATION OUTLOOK...PERIODS OF FLIGHT RESTRICTIONS...MOSTLY
DUE TO SUB-VFR CEILINGS...WILL ALTERNATE WITH PERIODS OF VFR
CONDITIONS THROUGH THE PERIOD.
&&
.MARINE...
WINDS AND SEAS ON THE INCREASE EARLY THIS MORNING WITH SOLID SMALL
CRAFT ADVISORY CONDITIONS ALL WATERS WITH THE CHARLESTON HARBOR
CLOSER TO 15 TO 20 KT AT 08Z. MODEL TRENDS FAVOR A 35 TO 40 KT
ONSHORE LOW LEVEL JET DEVELOPING TO THE S OF EDISTO BEACH AS THE
925 MB GRADIENT PINCHES BETWEEN THE STRONG HIGH TO THE N AND LOWER
PRES OVER FLORIDA. A TRICKY FORECAST AS MESOSCALE JETTING AND
PINCHING OF THE LOW LEVEL GRADIENT SEEMS OBVIOUS BUT THE PROBLEM
OF WHEN AND WHERE REMAIN DIFFICULT TO PINPOINT. THERE WAS ENOUGH
EVIDENCE IN THE MODEL FIELDS TO UPGRADE OUR GALE WATCH TO A
WARNING ALONG THE FAR SOUTHERN SOUTH CAROLINA COAST AND ALL
GEORGIA WATERS.
A TIGHT PRESSURE GRADIENT WILL MAINTAIN STRONG ONSHORE WINDS AND
HAZARDOUS SEAS FRIDAY THROUGH SATURDAY. GALE WARNINGS CONTINUE
INTO SATURDAY FOR WATERS SOUTH OF EDISTO BEACH...AND AT LEAST HIGH
END SMALL CRAFT ADVISORY CONDITIONS WILL PREVAIL ACROSS NORTHERN
SC WATERS. FORECAST ADJUSTMENTS COULD BE REQUIRED DUE TO A
PRESSURE GRADIENT WHICH WILL LIKELY CHANGE MAGNITUDE AND SHIFT
POSITION.
AS THE HIGH PRESSURE CENTERED NORTH OF THE REGION BEGINS TO
WEAKEN...WINDS WILL GRADUALLY DIMINISH SATURDAY NIGHT AND
SUNDAY...BUT SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY PERSIST ALL
AREAS THROUGH THE WEEKEND. THEN...WINDS WILL DIMINISH SIGNIFICANTLY
AND SEAS WILL SUBSIDE BELOW 6 FT ALL WATERS EARLY NEXT WEEK.
RIP CURRENTS...SUBTLE LONG PERIOD SWELL WITH STRONG ONSHORE WINDS
JUSTIFIES CONTINUING THE MODERATE RISK OF RIP CURRENTS TODAY.
INCREASING SURF AND ROUGH SEAS WILL OTHERWISE MAKE FOR NASTY
CONDITIONS FOR ANYONE IN THE WATERS AS THE LONGSHORE CURRENT
STRENGTHENS. THE ELEVATED RIP CURRENT RISK WILL PREVAIL THROUGH
THIS WEEKEND.
&&
.TIDES/COASTAL FLOODING...
THE POTENTIAL FOR BREAKERS UP TO 4 TO 6 FT THIS AFTERNOON AND
BEYOND WAS HIGH ENOUGH TO WARRANT THE ISSUANCE OF A HIGH SURF
ADVISORY ALONG THE GEORGIA COAST STARTING AT 15Z TODAY.
HIGH SURF POTENTIAL ALONG THE GEORGIA COAST WILL LINGER THROUGH
SAT. TIDAL DEPARTURES WILL BE 1 TO 2 FT ALONG OUR SOUTHERN COAST
HIGHEST WITH WATER HELD IN AT LOW TIDES. AT THIS TIME...SHALLOW
COASTAL FLOODING IS UNLIKELY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...HIGH SURF ADVISORY FROM 11 AM THIS MORNING TO 5 PM EDT
SATURDAY FOR GAZ117-119-139-141.
SC...NONE.
MARINE...GALE WARNING UNTIL 1 PM EDT SATURDAY FOR AMZ352-354.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR AMZ350.
GALE WARNING UNTIL 6 PM EDT SATURDAY FOR AMZ374.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT SATURDAY NIGHT FOR
AMZ330.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...SPR
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
356 PM CDT THU MAY 2 2013
.SYNOPSIS...
ISSUED AT 351 PM CDT THU MAY 2 2013
12Z UA ANALYSIS HAS 850MB LOWS ALONG THE KS/MO BORDER AND ANOTHER IN
WESTERN OKLAHOMA. A VERY STRONG 850MB THERMAL GRADIENT RAN FROM
MN/WI DOWN TO OKLAHOMA AND WEST TEXAS. SATELLITE TRENDS THROUGH MID
AFTERNOON SHOW THE LOW CLOUDS MAKING SLOW PROGRESS EASTWARD. RADAR
SHOWS THE MAIN RAIN SHIELD OVER CENTRAL AND NORTHEAST IOWA WITH
SCATTERED CONVECTION ACROSS ILLINOIS AND EASTERN IOWA.
18Z SFC ANALYSIS HAS WEAK LOWS FROM LOWER MICHIGAN BACK INTO
NORTHEAST ARKANSAS WITH THE FRONT CONNECTING ALL THE LOWS. DEW
POINTS ACROSS THE PLAINS AND PARTS OF THE UPPER MIDWEST WERE IN THE
20S AND 30S WITH 40S AND HIGHER FROM THE GREAT LAKES INTO THE LOWER
MISSISSIPPI VALLEY.
08
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 351 PM CDT THU MAY 2 2013
VERY DIFFICULT FCST. REFER TO THE CLIMATE SECTION FOR INFORMATION
REGARDING MAY SNOW FOR SOME LOCATIONS.
THE TRENDS WITH THE MODELS IS COLDER. THE MAIN PRECIPITATION SHIELD
IS ALONG AND BEHIND THE 850MB FRONT. THE RAP AND WRF TRENDS HAVE
THIS FRONT SLOWLY MOVING EAST TONIGHT. THUS RAIN WILL SLOWLY BREAK
OUT AND INCREASE IN AREAL COVERAGE DURING THE EVENING HOURS.
WBZ TEMPERATURES AND ACTUAL OBSERVATIONS SHOW TREMENDOUS EVAPORATIVE
COOLING WILL OCCUR ACROSS THE FAR NORTHWEST AND WESTERN PARTS OF THE
CWFA TONIGHT. FCST SOUNDINGS INDICATE RAIN BECOMING MIXED WITH AND
THEN CHANGING OVER TO SLEET/SNOW MIXTURE. THE OVERALL FORCING AND
WAA ALOFT IS SIGNIFICANT SO THERE WILL LIKELY BE ACCUMULATIONS ON
GRASSY SURFACES EVEN THOUGH THE GROUND IS QUITE WARM.
THEREFORE...WINTER WEATHER ADVISORIES HAVE BEEN RAISED FOR THE
WESTERN TWO ROWS OF COUNTIES FROM HWY 92 ON NORTH.
BUCHANAN...BENTON...IOWA...AND KEOKUK COUNTIES HAVE THE BEST CHANCE
AT SEEING POTENTIALLY HISTORIC SNOWFALL FOR MAY. THE HIGHEST
SNOWFALL AMOUNTS WILL BE IN THE WESTERN PARTS OF THESE COUNTIES.
SNOW/SLEET AMOUNTS THERE COULD RANGE FROM 1 TO 4 INCHES.
FURTHER EAST...ACROSS DELAWARE...LINN...JOHNSON...AND WASHINGTON
COUNTIES THE CHANGE OVER TO SLEET WILL OCCUR DURING THE EVENING. IN
THIS AREA MORE SLEET THAN SNOW IS EXPECTED WITH THE HIGHER AMOUNTS
IN THE WESTERN PARTS OF THESE COUNTIES. SNOW/SLEET AMOUNTS IN THIS
AREA COULD RANGE FROM A DUSTING TO 1 INCH.
THE OVERALL LARGE PICTURE SUGGESTS THE POTENTIAL FOR SOME SLEET AS
FAR EAST AS A DUBUQUE IOWA TO KAHOKA MISSOURI LINE DUE TO
EVAPORATIVE COOLING. IN THIS AREA ONLY TRACE AMOUNTS ARE EXPECTED.
ROUGHLY ALONG AND EAST OF THE MISSISSIPPI...SHOWERS WILL GIVE WAY TO
A WIDESPREAD RAIN AS THE WAA INCREASES.
FRIDAY...THE SNOW/SLEET MIXTURE IN THE FAR NORTHWEST/WEST PARTS OF
THE CWFA WILL CHANGE BACK TO ALL RAIN AS WARM AIR ALOFT MOVES INTO
THE AREA. ACROSS THE EASTERN CWFA THE OVERALL FORCING INCREASES AS A
SFC WAVE MOVES UP FROM THE SOUTH. ALTHOUGH NOT INCLUDED IN THE
FORECAST...THE LIFT TOOL SUGGESTS POSSIBLY SOME ISOLATED THUNDER
OVER THE FAR SOUTHEAST AND EASTERN PARTS OF THE CWFA AS STRONG
CONVERGENCE MOVES ALONG A THETA E GRADIENT.
08
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 351 PM CDT THU MAY 2 2013
RECORD COLD RAIN...SLEET...SNOW EVENT MAIN CHALLENGE THIS FORECAST.
OVERVIEW...INITIALIZATION AND VERIFICATION GOOD WITH MAIN ISSUE THE
PHASING OF LATENT HEAT RELEASE AND STRONG EVAPORATIVE COOLING TO
DETERMINE WHAT FAR WESTERN SECTIONS RECEIVE SLEET AND SNOW TONIGHT.
VERIFICATION AT 18Z SUPPORTS FORCING AND THERMAL FIELDS OF 12Z NAM-
WRF AND HI-RES ECMWF. THIS SUPPORTS SOME ACCUMULATIONS OF SNOW AND
QUITE A BIT OF SLEET FAR WEST SECTIONS. HEAVY RAIN AND FORCING
TOOLS SUGGEST MOST OF AREA TO PICK UP 1.5 TO LOCALLY AROUND 2.5
INCHES OF TOTAL PRECIPITATION NEXT 2-3 DAYS WITH MOST FALLING
FRIDAY AND FRIDAY NIGHT. STRATIFORM NATURE AND AMOUNTS OVER LONGER
TIME PERIOD SUPPORT MINOR RIVER ISSUES ON SOME RIVERS.
FRIDAY NIGHT...KEPT CATEGORICAL POPS WITH DEEPLY OCCLUDING AND
MATURING RAIN OF UPPER LOW TO DEPOSIT MOSTLY 1/3 TO 2/3 OF AN INCH
WITH HEAVIEST OVER SW 1/2 TO 2/3 OF AREAL TEMPERATURES WITH MILDER
AIR FROM EAST TO ALLOW TEMPERATURES TO BE NEARLY STEADY WITH LOWER
50S EAST TO MID/UPPER 40S FAR WEST.
SATURDAY AND SUNDAY...MINOR CHANGES MADE. CONSIDERABLE CLOUDS WITH
PERIODS OF LIGHT RAIN SATURDAY AND SATURDAY AND VERY LIGHT RAIN
SUNDAY. A QUARTER INCH OR LESS ON SATURDAY MOST LOCATIONS WITH
SPOTTY VERY LIGHT AMOUNTS SUNDAY. TEMPERATURES COOL WITH MOSTLY
LOWER TO MIDDLE 60S AND MINS SATURDAY NIGHT IN THE MID/UPPER 40S.
NICHOLS
DAYS 4 THROUGH 7...SUNDAY NIGHT THROUGH THURSDAY...
SUNDAY NIGHT THROUGH MONDAY NIGHT THE DEEP UPPER LOW GRADUALLY
SHIFTS SOUTHEAST...AND A SURFACE RIDGE BUILDS INTO THE AREA TO CAUSE
OUR SCATTERED SHOWERS TO SLOWLY DIMINISH IN COVERAGE...SO THAT BY
MONDAY NIGHT WE SHOULD BE COMPLETELY DRY. TEMPERATURES TO REMAIN
BELOW NORMAL WITH LOWS IN THE 40S. MONDAY HIGHS ARE CURRENTLY
FORECAST TO RISE INTO THE UPPER 60S...BUT IT TOO MUCH CLOUD COVER IS
LINGERING WILL HAVE TO LOWER THESE VALUES.
TUESDAY AND TUESDAY NIGHT THE SURFACE RIDGE SLOWLY SHIFTS EAST
ACROSS THE AREA...PRODUCING MAINLY DRY CONDITIONS AND GRADUALLY
WARMING TEMPERATURES. AM CARRYING SOME DAYTIME SLIGHT CHANCE POPS
IN THE SOUTHWEST CLOSEST TO THE LINGERING PLUME OF MOISTURE WHERE WE
MIGHT GET SOME DIURNALLY DRIVEN SHOWERS. HIGHS TUESDAY SHOULD GET
APPROACH 70 WITH 850MB TEMPERATURES GRADUALLY WARMING AS WELL.
TUESDAY NIGHT MINS TO MODERATE TO AROUND 50.
WEDNESDAY AND THURSDAY QUITE A BIT OF UNCERTAINTY RE-ENTERS THE
FORECAST. WE WILL BE IN A SPLIT FLOW WITH A NORTHERN STREAM MAINLY
AFFECTING SOUTHERN CANADA AND THE FAR NORTHERN CONUS...AND THE
SOUTHERN STREAM MAINLY AFFECTING THE SOUTHERN CONUS. MODELS ARE
DIVERGING IN THE HANDLING OF A SHORTWAVE THAT MOVES THROUGH THE
NORTHERN STREAM...AND HOW MUCH IT PHASES WITH A CUT OFF LOW IN THE
SOUTHERN STREAM OVER THE SOUTHWEST CONUS. THE ECMWF IS FASTER AND
IS PHASING IT MORE...AND DRAGGING MORE MOISTURE UP INTO THE
AREA...PRODUCING PRECIPITATION BEGINNING WEDNESDAY NIGHT. THE GFS
IS SLOWER AND PHASES IT LESS...AND DOES NOT BRING PRECIPITATION INTO
THE AREA UNTIL THURSDAY NIGHT. THUS...WHILE I AM CARRYING SOME
SLIGHT CHANCE POPS BEGINNING ON WEDNESDAY...THESE ARE MORE FOR A
CONTINUATION OF THE DIURNAL SHOWERS DURING THE DAY WITH THE
GRADUALLY INCREASING MOISTURE. AM BRINGING IN SOME LOW CHANCE POPS
FOR THURSDAY IN ASSOCIATION WITH THE NEW SHORTWAVE. TEMPERATURES TO
CONTINUE TO WARM THROUGH AT LEAST WEDNESDAY NIGHT...WITH HIGHS ON
WEDNESDAY INTO THE LOWER 70S. THURSDAY STILL FAIRLY WARM IN THE
FORECAST BUT THIS MAY NEED TO BE LOWERED IF PRECIPITATION MOVES INTO
THE AREA SOONER.
LE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 351 PM CDT THU MAY 2 2013
CONDITIONS RANGE FROM VFR TO IFR. MVFR/IFR CONDITIONS WILL
OVERSPREAD EASTERN IOWA AND NORTHERN ILLINOIS THROUGH 12Z/03 WITH
LIFR CONDITIONS LIKELY. ACCUMULATING SNPL IS VERY POSSIBLE AT KCID
AND MAY OCCUR AT KDBQ.
08
&&
.CLIMATE...
ISSUED AT 351 PM CDT THU MAY 2 2013
MAY SNOWFALL IN IOWA IS RARE.
A VERY QUICK LOOK BACK AT PAST WEATHER RECORDS SUGGESTS THAT THE
LAST TIME A FAIRLY WIDESPREAD SNOW OCCURRED IN MAY ACROSS IOWA WAS
IN 1966. BELOW IS WHEN MEASURABLE SNOW AND/OR SLEET FELL IN MAY
FOR SELECTED SITES.
CEDAR RAPIDS #1 (MARION)...
0.2 INCHES 05/01/1997 FELL AS SLEET
0.3 INCHES 05/11/1966
DUBUQUE IOWA...
3.1 INCHES 05/01/1966
1.0 INCHES 05/07-08/1960
IOWA CITY WWTP...
0.2 INCHES 05/05/1944
MOLINE ILLINOIS...
0.3 INCHES ON 05/03/1935
TRACE ON 05/06/1989
TRACE ON 05/22/1917*
* LATEST RECORDED SNOWFALL ON RECORD
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 10 AM CDT FRIDAY FOR BENTON-
BUCHANAN-IOWA-KEOKUK.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 8 AM CDT
FRIDAY FOR DELAWARE-JOHNSON-LINN-WASHINGTON.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...NICHOLS/LE
AVIATION...08
CLIMATE...08
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
659 AM CDT THU MAY 2 2013
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1038 PM CDT WED MAY 1 2013
THE 02.00Z 250 HPA RAOB MAP SHOWED STRONG FLOW ACROSS THE ROCKIES AND
ACROSS THE NORTHERN PLAINS ASSOCIATED WITH A LARGE SCALE TROF. MAGNITUDES
WERE AROUND 100 KT. STRONGER FLOW OF 130 KT WAS NOTED ACROSS WESTERN
ONTARIO. AT 500 HPA, A VERY IMPRESSIVE FOR 02 MAY COLD POOL OF -30 DEG
C TO -33 DEG C WAS NOTED ACROSS MONTANA AND WYOMING. THIS WAS ASSOCIATED
WITH THE AFOREMENTIONED TROF. AT 700 HPA, AN IMPRESSIVE TEMPERATURE
GRADIENT BETWEEN KDDC (+3 DEG C) AND KLBF (-8 DEG C) WAS NOTED. FARTHER
UPSTREAM, MID LEVEL TEMPERATURES WERE EVEN COLDER WITH -15 DEG C AT
KGGW AT -18 DEG C AT CYQD. AT 850 HPA, THE AMOUNT OF COLD AIR ADVECTION
BETWEEN 00Z SYNOPTIC FLIGHTS WAS TREMENDOUS (25 DEG C TO -3 DEG C AT
KDDC). IN FACT, THE OBSERVED VALUE OF -2.8 DEG C IS WELL BELOW 2 STANDARD
DEVIATIONS AND CLOSER TO THE MINIMUM OF -5 DEG C FOR 850 HPA STATISTICS.
THIS IS OBVIOUSLY AT THE TAIL END OF EXTREMES FOR A GAUSSIAN DISTRIBUTION.
AT THE SURFACE, A STRONG COLD FRONT HAD PUSHED WELL SOUTH OF THE REGION.
A 1038 HPA ANTICYCLONE WAS BUILDING IN THE WAKE OF THE FRONT ACROSS
THE HIGH PLAINS. WSR-88D RADAR MOSAIC SHOWED SNOW ACROSS NW KANSAS AND
CONVECTION ACROSS SC KANSAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT THU MAY 2 2013
BUSY MORNING WITH NUMEROUS SENSIBLE WEATHER IMPACTS AND RESULTANT
GRID MODIFICATIONS.
THIS MORNING:
KDDC WSR-88D REFLECTIVITY AND SURFACE OBSERVATIONS CONTINUE TO INDICATE
A BAND OF SNOW MOVING ACROSS WESTERN KANSAS EARLY THIS MORNING. A QUICK
LOOK AT KDOT CAMERAS DO SHOW THAT SOME OF THE SNOW IS STICKING TO THE
ROADWAYS ACROSS THE INTERSTATE 70 CORRIDOR. AFTER CHECKING NAM/WRF/RAP/AND
HRRR MODELS, IT APPEARS THAT THE HRRR IS DOING THE BETTER JOB WITH SNOW
FORECASTS COMPARED WITH ACTUAL LSR`S UPSTREAM. AS A RESULT, HEAVILY
BIASED THE NEAR TERM FORECAST TO HRRR OUTPUT SOLUTIONS. THE SNOW IS
IN ASSOCIATION WITH A TIGHT 700 HPA BAROCLINIC AS WELL AS THE PASSAGE
AND RESULTANT SYNOPTIC FORCING OF A 250 HPA JET STREAK (RIGHT ENTRANCE
REGION). HAVE ISSUED A WINTER WEATHER ADVISORY FOR NW/N PORTIONS OF
THE FORECAST AREA OF RESPONSIBILITY. MOST ACCUMULATION SHOULD BE ON
GRASSY/ELEVATED SURFACES, BUT IT WOULD NOT TAKE MUCH TO GET TEMPORARY
HAZARDOUS TRAVEL CONDITIONS. THIS IS TRULY AN IMPRESSIVE EVENT WITH
CURRENT OBSERVATIONS. FOR OTHER RELATED INFORMATION, SEE THE SYNOPSIS
AND WSW.
ELSEWHERE, MINIMUM TEMPERATURES FOR THIS MORNING APPEAR TO BE ON TRACK
AND WILL CONTINUE THE FREEZE WARNING AS IS.
TODAY:
TODAY WILL BE COLD WITH MAXIMUM TEMPERATURES IN THE 40S. STRATUS WILL
STICK AROUND FOR THE FIRST HALF OF TODAY SO TEMPERATURES WILL NOT GET
THE CHANCE TO CLIMB. THE COLDEST TEMPERATURES ARE FORECAST ACROSS SC
KANSAS WHERE CLOUDS AND PRECIPITATION WILL RESIDE LONGER. THE OTHER
CONCERN FOR TODAY IS WINDS. 850 HPA WINDS AROUND 50 KT AND A TIGHT PRESSURE
GRADIENT DO SPELL OUT THE CONCERN FOR A WIND ADVISORY GENERALLY SOUTH
OF THE ARKANSAS RIVER. HAVE ISSUED AS A RESULT WITH THE NAM SHOWING
WIND ADVISORY CRITERIA FOR THE SOUTHERN ROW OF COUNTIES EXCEPT MORTON
COUNTY.
TONIGHT:
THE MAIN SYNOPTIC WAVE WILL BE EAST OF THE REGION BY LATE TONIGHT. SUBSIDENCE
AND DRY AIR ADVECTION IS EXPECTED IN THE WAKE OF THE TROF. HIGH PRESSURE
WILL BUILD AT THE SURFACE WITH WINDS BECOMING LIGHT. HAVE UPGRADED THE
TWO WATCHES TO WARNINGS WITH A HARD FREEZE WARNING COVERING MUCH OF
THE FORECAST AREA OF RESPONSIBILITY EXCEPT ACROSS PORTIONS OF SC KANSAS
WHERE MINIMUMS WILL BE SLIGHTLY MORE "MILD". STILL, WE ARE LOOKING AT
VERY COLD LOWS WITH MINIMUMS MAINLY IN THE 20S DEG F.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 356 AM CDT THU MAY 2 2013
BY FRIDAY MORNING, THE DEEP UPPER TROUGH OVER THE NORTHERN AND
CENTRAL PLAINS WILL BE CLOSING OFF INTO AN UPPER LOW CENTERED ALONG
THE BORDER OF SOUTHEAST KANSAS AND NORTHEAST OKLAHOMA. FROM THERE,
THE MEDIUM RANGE MODELS MOVE THE LOW EAST ALONG THE BORDER OF
MISSOURI AND ARKANSAS THROUGH SATURDAY. THE MODELS ARE SHOWING A
LOBE OF VORTICITY ROTATING AROUND THE NORTH SIDE OF THE UPPER LOW
AND BACK INTO CENTRAL AND PARTS OF WESTERN KANSAS ON SATURDAY. THE
NAM AND GFS ARE SHOWING SOME LIGHT PRECIPITATION SPREADING INTO
CENTRAL AND PARTS OF WESTERN KANSAS DURING THE DAY SATURDAY AS WELL.
THE UKMET ALSO SHOWS THIS WHILE THE ECMWF AND GEM ARE NOT AS
AGGRESSIVE. IN COLLABORATION WITH SURROUNDING OFFICES, HAVE BUMPED
UP POPS FOR LIGHT RAIN SOMEWHAT DURING THE DAY SATURDAY WITH POPS
TAPERING OFF BY SATURDAY EVENING.
WE SHOULD HAVE A FEW DAYS OF DRY WEATHER DURING THE EARLY PART OF
NEXT WEEK AS THE CLOSED UPPER LOW CONTINUES TO MOVE INTO THE
SOUTHEASTERN STATES AND WEAK UPPER LEVEL RIDGING DOMINATES THE
CENTRAL PLAINS. THE MODELS TEND TO AGREE THAT ANOTHER UPPER LOW WILL
FORM OVER THE NORTHERN ROCKIES AND DIG SOUTHWESTWARD TO JUST OFF THE
CALIFORNIA COAST BY SUNDAY EVENING. AFTER THIS TIME THE MODELS
REALLY DIVERGE WITH HOW THIS SYSTEM EVOLVES AND MOVES EASTWARD
TOWARD THE PLAINS BUT ALL THE MODELS ARE MORE OR LESS SHOWING AN
INITIAL PIECE OF ENERGY EJECTING OUT TOWARD THE CENTRAL PLAINS AND
INCREASING CHANCES FOR SHOWERS ACROSS WESTERN KANSAS BY MONDAY NIGHT
AND TUESDAY. THE MAIN UPPER LOW OPENS UP SOMEWHAT AS IT MOVES OUT
OVER THE CENTRAL PLAINS THROUGH THE MIDDLE PART OF NEXT WEEK. THE
LATEST ALLBLEND HAS SLIGHT CHANCE OR CHANCE POPS THROUGH THE MIDDLE
PART OF NEXT WEEK. SUFFICE IT TO SAY THAT IT IS DIFFICULT TO NARROW
DOWN ANY SPECIFIC DAYS THAT PRECIPITATION CHANCES WILL BE THE BEST
DURING THAT TIME PERIOD GIVEN THE MODEL DIFFERENCES SO WILL KEEP
CHANCES FOR PRECIPITATION IN THE FORECAST THROUGH THURSDAY BEFORE
CHANCES SHOULD BE DECREASING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 659 AM CDT THU MAY 2 2013
LIGHT SNOW WILL BE ENDING BY 14Z AT THE TAF SITES ACROSS SOUTHWEST
KANSAS. MVFR/IFR CIGS WILL BECOME VFR BY 15-17Z. NORTH WINDS WILL
CONTINUE GUSTY AT 15 TO 25 KNOTS BUT WILL DIMINISH FAIRLY QUICKLY
BY 00Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 27 56 34 / 50 0 10 10
GCK 47 26 58 33 / 30 0 0 10
EHA 46 27 60 36 / 30 0 0 0
LBL 46 25 59 35 / 50 0 0 0
HYS 47 27 52 34 / 40 0 10 20
P28 44 31 54 36 / 100 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING FROM 11 PM CDT /10 PM MDT/ THIS EVENING TO 1
PM CDT /NOON MDT/ FRIDAY FOR KSZ030-031-043>046-061>065-074>078-
084>087.
WINTER WEATHER ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ030-
043>045.
FREEZE WARNING UNTIL 10 AM CDT /9 AM MDT/ THIS MORNING FOR
KSZ030-031-043>046-061>065-074>080-084>088.
FREEZE WARNING FROM 11 PM THIS EVENING TO 1 PM CDT FRIDAY FOR
KSZ066-079>081-088>090.
WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR KSZ085>090.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
357 AM CDT THU MAY 2 2013
...UPDATED LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1038 PM CDT WED MAY 1 2013
THE 02.00Z 250 HPA RAOB MAP SHOWED STRONG FLOW ACROSS THE ROCKIES AND
ACROSS THE NORTHERN PLAINS ASSOCIATED WITH A LARGE SCALE TROF. MAGNITUDES
WERE AROUND 100 KT. STRONGER FLOW OF 130 KT WAS NOTED ACROSS WESTERN
ONTARIO. AT 500 HPA, A VERY IMPRESSIVE FOR 02 MAY COLD POOL OF -30 DEG
C TO -33 DEG C WAS NOTED ACROSS MONTANA AND WYOMING. THIS WAS ASSOCIATED
WITH THE AFOREMENTIONED TROF. AT 700 HPA, AN IMPRESSIVE TEMPERATURE
GRADIENT BETWEEN KDDC (+3 DEG C) AND KLBF (-8 DEG C) WAS NOTED. FARTHER
UPSTREAM, MID LEVEL TEMPERATURES WERE EVEN COLDER WITH -15 DEG C AT
KGGW AT -18 DEG C AT CYQD. AT 850 HPA, THE AMOUNT OF COLD AIR ADVECTION
BETWEEN 00Z SYNOPTIC FLIGHTS WAS TREMENDOUS (25 DEG C TO -3 DEG C AT
KDDC). IN FACT, THE OBSERVED VALUE OF -2.8 DEG C IS WELL BELOW 2 STANDARD
DEVIATIONS AND CLOSER TO THE MINIMUM OF -5 DEG C FOR 850 HPA STATISTICS.
THIS IS OBVIOUSLY AT THE TAIL END OF EXTREMES FOR A GAUSSIAN DISTRIBUTION.
AT THE SURFACE, A STRONG COLD FRONT HAD PUSHED WELL SOUTH OF THE REGION.
A 1038 HPA ANTICYCLONE WAS BUILDING IN THE WAKE OF THE FRONT ACROSS
THE HIGH PLAINS. WSR-88D RADAR MOSAIC SHOWED SNOW ACROSS NW KANSAS AND
CONVECTION ACROSS SC KANSAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT THU MAY 2 2013
BUSY MORNING WITH NUMEROUS SENSIBLE WEATHER IMPACTS AND RESULTANT
GRID MODIFICATIONS.
THIS MORNING:
KDDC WSR-88D REFLECTIVITY AND SURFACE OBSERVATIONS CONTINUE TO INDICATE
A BAND OF SNOW MOVING ACROSS WESTERN KANSAS EARLY THIS MORNING. A QUICK
LOOK AT KDOT CAMERAS DO SHOW THAT SOME OF THE SNOW IS STICKING TO THE
ROADWAYS ACROSS THE INTERSTATE 70 CORRIDOR. AFTER CHECKING NAM/WRF/RAP/AND
HRRR MODELS, IT APPEARS THAT THE HRRR IS DOING THE BETTER JOB WITH SNOW
FORECASTS COMPARED WITH ACTUAL LSR`S UPSTREAM. AS A RESULT, HEAVILY
BIASED THE NEAR TERM FORECAST TO HRRR OUTPUT SOLUTIONS. THE SNOW IS
IN ASSOCIATION WITH A TIGHT 700 HPA BAROCLINIC AS WELL AS THE PASSAGE
AND RESULTANT SYNOPTIC FORCING OF A 250 HPA JET STREAK (RIGHT ENTRANCE
REGION). HAVE ISSUED A WINTER WEATHER ADVISORY FOR NW/N PORTIONS OF
THE FORECAST AREA OF RESPONSIBILITY. MOST ACCUMULATION SHOULD BE ON
GRASSY/ELEVATED SURFACES, BUT IT WOULD NOT TAKE MUCH TO GET TEMPORARY
HAZARDOUS TRAVEL CONDITIONS. THIS IS TRULY AN IMPRESSIVE EVENT WITH
CURRENT OBSERVATIONS. FOR OTHER RELATED INFORMATION, SEE THE SYNOPSIS
AND WSW.
ELSEWHERE, MINIMUM TEMPERATURES FOR THIS MORNING APPEAR TO BE ON TRACK
AND WILL CONTINUE THE FREEZE WARNING AS IS.
TODAY:
TODAY WILL BE COLD WITH MAXIMUM TEMPERATURES IN THE 40S. STRATUS WILL
STICK AROUND FOR THE FIRST HALF OF TODAY SO TEMPERATURES WILL NOT GET
THE CHANCE TO CLIMB. THE COLDEST TEMPERATURES ARE FORECAST ACROSS SC
KANSAS WHERE CLOUDS AND PRECIPITATION WILL RESIDE LONGER. THE OTHER
CONCERN FOR TODAY IS WINDS. 850 HPA WINDS AROUND 50 KT AND A TIGHT PRESSURE
GRADIENT DO SPELL OUT THE CONCERN FOR A WIND ADVISORY GENERALLY SOUTH
OF THE ARKANSAS RIVER. HAVE ISSUED AS A RESULT WITH THE NAM SHOWING
WIND ADVISORY CRITERIA FOR THE SOUTHERN ROW OF COUNTIES EXCEPT MORTON
COUNTY.
TONIGHT:
THE MAIN SYNOPTIC WAVE WILL BE EAST OF THE REGION BY LATE TONIGHT. SUBSIDENCE
AND DRY AIR ADVECTION IS EXPECTED IN THE WAKE OF THE TROF. HIGH PRESSURE
WILL BUILD AT THE SURFACE WITH WINDS BECOMING LIGHT. HAVE UPGRADED THE
TWO WATCHES TO WARNINGS WITH A HARD FREEZE WARNING COVERING MUCH OF
THE FORECAST AREA OF RESPONSIBILITY EXCEPT ACROSS PORTIONS OF SC KANSAS
WHERE MINIMUMS WILL BE SLIGHTLY MORE "MILD". STILL, WE ARE LOOKING AT
VERY COLD LOWS WITH MINIMUMS MAINLY IN THE 20S DEG F.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 356 AM CDT THU MAY 2 2013
BY FRIDAY MORNING, THE DEEP UPPER TROUGH OVER THE NORTHERN AND
CENTRAL PLAINS WILL BE CLOSING OFF INTO AN UPPER LOW CENTERED ALONG
THE BORDER OF SOUTHEAST KANSAS AND NORTHEAST OKLAHOMA. FROM THERE,
THE MEDIUM RANGE MODELS MOVE THE LOW EAST ALONG THE BORDER OF
MISSOURI AND ARKANSAS THROUGH SATURDAY. THE MODELS ARE SHOWING A
LOBE OF VORTICITY ROTATING AROUND THE NORTH SIDE OF THE UPPER LOW
AND BACK INTO CENTRAL AND PARTS OF WESTERN KANSAS ON SATURDAY. THE
NAM AND GFS ARE SHOWING SOME LIGHT PRECIPITATION SPREADING INTO
CENTRAL AND PARTS OF WESTERN KANSAS DURING THE DAY SATURDAY AS WELL.
THE UKMET ALSO SHOWS THIS WHILE THE ECMWF AND GEM ARE NOT AS
AGGRESSIVE. IN COLLABORATION WITH SURROUNDING OFFICES, HAVE BUMPED
UP POPS FOR LIGHT RAIN SOMEWHAT DURING THE DAY SATURDAY WITH POPS
TAPERING OFF BY SATURDAY EVENING.
WE SHOULD HAVE A FEW DAYS OF DRY WEATHER DURING THE EARLY PART OF
NEXT WEEK AS THE CLOSED UPPER LOW CONTINUES TO MOVE INTO THE
SOUTHEASTERN STATES AND WEAK UPPER LEVEL RIDGING DOMINATES THE
CENTRAL PLAINS. THE MODELS TEND TO AGREE THAT ANOTHER UPPER LOW WILL
FORM OVER THE NORTHERN ROCKIES AND DIG SOUTHWESTWARD TO JUST OFF THE
CALIFORNIA COAST BY SUNDAY EVENING. AFTER THIS TIME THE MODELS
REALLY DIVERGE WITH HOW THIS SYSTEM EVOLVES AND MOVES EASTWARD
TOWARD THE PLAINS BUT ALL THE MODELS ARE MORE OR LESS SHOWING AN
INITIAL PIECE OF ENERGY EJECTING OUT TOWARD THE CENTRAL PLAINS AND
INCREASING CHANCES FOR SHOWERS ACROSS WESTERN KANSAS BY MONDAY NIGHT
AND TUESDAY. THE MAIN UPPER LOW OPENS UP SOMEWHAT AS IT MOVES OUT
OVER THE CENTRAL PLAINS THROUGH THE MIDDLE PART OF NEXT WEEK. THE
LATEST ALLBLEND HAS SLIGHT CHANCE OR CHANCE POPS THROUGH THE MIDDLE
PART OF NEXT WEEK. SUFFICE IT TO SAY THAT IT IS DIFFICULT TO NARROW
DOWN ANY SPECIFIC DAYS THAT PRECIPITATION CHANCES WILL BE THE BEST
DURING THAT TIME PERIOD GIVEN THE MODEL DIFFERENCES SO WILL KEEP
CHANCES FOR PRECIPITATION IN THE FORECAST THROUGH THURSDAY BEFORE
CHANCES SHOULD BE DECREASING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1200 AM CDT THU MAY 2 2013
POOR FLIGHT CONDITIONS WITH IFR CIGS EXPECTED THROUGH THE OVERNIGHT
HOURS IN ASSOCIATION WITH -SN AND LOW STRATUS. SYSTEM WILL EXIT OUT
OF THE REGION THROUGH THE AFTERNOON WITH FLIGHT CONDITIONS IMPROVING
WITH TIME. WINDS WILL BE NORTHERLY 20-30 KT THROUGH MOST OF THE TAF
PD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 27 56 34 / 50 0 10 10
GCK 47 26 58 33 / 30 0 0 10
EHA 46 27 60 36 / 30 0 0 0
LBL 46 25 59 35 / 50 0 0 0
HYS 47 27 52 34 / 40 0 10 20
P28 44 31 54 36 / 100 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING FROM 11 PM CDT /10 PM MDT/ THIS EVENING TO 1
PM CDT /NOON MDT/ FRIDAY FOR KSZ030-031-043>046-061>065-074>078-
084>087.
WINTER WEATHER ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ030-
043>045.
FREEZE WARNING UNTIL 10 AM CDT /9 AM MDT/ THIS MORNING FOR
KSZ030-031-043>046-061>065-074>080-084>088.
FREEZE WARNING FROM 11 PM THIS EVENING TO 1 PM CDT FRIDAY FOR
KSZ066-079>081-088>090.
WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR KSZ085>090.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
309 AM CDT THU MAY 2 2013
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1038 PM CDT WED MAY 1 2013
THE 02.00Z 250 HPA RAOB MAP SHOWED STRONG FLOW ACROSS THE ROCKIES AND
ACROSS THE NORTHERN PLAINS ASSOCIATED WITH A LARGE SCALE TROF. MAGNITUDES
WERE AROUND 100 KT. STRONGER FLOW OF 130 KT WAS NOTED ACROSS WESTERN
ONTARIO. AT 500 HPA, A VERY IMPRESSIVE FOR 02 MAY COLD POOL OF -30 DEG
C TO -33 DEG C WAS NOTED ACROSS MONTANA AND WYOMING. THIS WAS ASSOCIATED
WITH THE AFOREMENTIONED TROF. AT 700 HPA, AN IMPRESSIVE TEMPERATURE
GRADIENT BETWEEN KDDC (+3 DEG C) AND KLBF (-8 DEG C) WAS NOTED. FARTHER
UPSTREAM, MID LEVEL TEMPERATURES WERE EVEN COLDER WITH -15 DEG C AT
KGGW AT -18 DEG C AT CYQD. AT 850 HPA, THE AMOUNT OF COLD AIR ADVECTION
BETWEEN 00Z SYNOPTIC FLIGHTS WAS TREMENDOUS (25 DEG C TO -3 DEG C AT
KDDC). IN FACT, THE OBSERVED VALUE OF -2.8 DEG C IS WELL BELOW 2 STANDARD
DEVIATIONS AND CLOSER TO THE MINIMUM OF -5 DEG C FOR 850 HPA STATISTICS.
THIS IS OBVIOUSLY AT THE TAIL END OF EXTREMES FOR A GAUSSIAN DISTRIBUTION.
AT THE SURFACE, A STRONG COLD FRONT HAD PUSHED WELL SOUTH OF THE REGION.
A 1038 HPA ANTICYCLONE WAS BUILDING IN THE WAKE OF THE FRONT ACROSS
THE HIGH PLAINS. WSR-88D RADAR MOSAIC SHOWED SNOW ACROSS NW KANSAS AND
CONVECTION ACROSS SC KANSAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT THU MAY 2 2013
BUSY MORNING WITH NUMEROUS SENSIBLE WEATHER IMPACTS AND RESULTANT
GRID MODIFICATIONS.
THIS MORNING:
KDDC WSR-88D REFLECTIVITY AND SURFACE OBSERVATIONS CONTINUE TO INDICATE
A BAND OF SNOW MOVING ACROSS WESTERN KANSAS EARLY THIS MORNING. A QUICK
LOOK AT KDOT CAMERAS DO SHOW THAT SOME OF THE SNOW IS STICKING TO THE
ROADWAYS ACROSS THE INTERSTATE 70 CORRIDOR. AFTER CHECKING NAM/WRF/RAP/AND
HRRR MODELS, IT APPEARS THAT THE HRRR IS DOING THE BETTER JOB WITH SNOW
FORECASTS COMPARED WITH ACTUAL LSR`S UPSTREAM. AS A RESULT, HEAVILY
BIASED THE NEAR TERM FORECAST TO HRRR OUTPUT SOLUTIONS. THE SNOW IS
IN ASSOCIATION WITH A TIGHT 700 HPA BAROCLINIC AS WELL AS THE PASSAGE
AND RESULTANT SYNOPTIC FORCING OF A 250 HPA JET STREAK (RIGHT ENTRANCE
REGION). HAVE ISSUED A WINTER WEATHER ADVISORY FOR NW/N PORTIONS OF
THE FORECAST AREA OF RESPONSIBILITY. MOST ACCUMULATION SHOULD BE ON
GRASSY/ELEVATED SURFACES, BUT IT WOULD NOT TAKE MUCH TO GET TEMPORARY
HAZARDOUS TRAVEL CONDITIONS. THIS IS TRULY AN IMPRESSIVE EVENT WITH
CURRENT OBSERVATIONS. FOR OTHER RELATED INFORMATION, SEE THE SYNOPSIS
AND WSW.
ELSEWHERE, MINIMUM TEMPERATURES FOR THIS MORNING APPEAR TO BE ON TRACK
AND WILL CONTINUE THE FREEZE WARNING AS IS.
TODAY:
TODAY WILL BE COLD WITH MAXIMUM TEMPERATURES IN THE 40S. STRATUS WILL
STICK AROUND FOR THE FIRST HALF OF TODAY SO TEMPERATURES WILL NOT GET
THE CHANCE TO CLIMB. THE COLDEST TEMPERATURES ARE FORECAST ACROSS SC
KANSAS WHERE CLOUDS AND PRECIPITATION WILL RESIDE LONGER. THE OTHER
CONCERN FOR TODAY IS WINDS. 850 HPA WINDS AROUND 50 KT AND A TIGHT PRESSURE
GRADIENT DO SPELL OUT THE CONCERN FOR A WIND ADVISORY GENERALLY SOUTH
OF THE ARKANSAS RIVER. HAVE ISSUED AS A RESULT WITH THE NAM SHOWING
WIND ADVISORY CRITERIA FOR THE SOUTHERN ROW OF COUNTIES EXCEPT MORTON
COUNTY.
TONIGHT:
THE MAIN SYNOPTIC WAVE WILL BE EAST OF THE REGION BY LATE TONIGHT. SUBSIDENCE
AND DRY AIR ADVECTION IS EXPECTED IN THE WAKE OF THE TROF. HIGH PRESSURE
WILL BUILD AT THE SURFACE WITH WINDS BECOMING LIGHT. HAVE UPGRADED THE
TWO WATCHES TO WARNINGS WITH A HARD FREEZE WARNING COVERING MUCH OF
THE FORECAST AREA OF RESPONSIBILITY EXCEPT ACROSS PORTIONS OF SC KANSAS
WHERE MINIMUMS WILL BE SLIGHTLY MORE "MILD". STILL, WE ARE LOOKING AT
VERY COLD LOWS WITH MINIMUMS MAINLY IN THE 20S DEG F.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 317 PM CDT WED MAY 1 2013
VERY COLD TEMPERATURES FOR THIS TIME OF THE YEAR ARE EXPECTED FRIDAY
MORNING AS THE UPPER LEVEL LOW MOVES INTO EASTERN KANSAS AND SKIES
BECOME MOSTLY CLEAR. LOWS FRIDAY MORNING ARE FORECASTED TO DIP BELOW
FREEZING ACROSS ALL OF WESTERN KANSAS. A FREEZE WARNING CONTINUES
EAST AND SOUTH OF A LINE FROM LARNED TO MEADE AND A HARD FREEZE
WATCH NORTH AND WEST OF THIS LINE.
MODELS THEN BECOME IN SOMEWHAT DISAGREEMENT ON THE TRACK OF THE
UPPER LEVEL LOW THIS WEEKEND. ALL MODELS HAVE IT SPINNING INTO THE
MISSISSIPPI VALLEY BY SUNDAY. HOWEVER, THE GEM PLACES IT ACROSS THE
UPPER MISSISSIPPI VALLEY, THE ECMWF ACROSS THE MID MISSISSIPPI
VALLEY, AND THE GFS A LITTLE FARTHER SOUTH ACROSS ARKANSAS AND
TENNESSEE. NEVERTHELESS, THIS LOW WILL AFFECT PORTIONS OF CENTRAL
AND SOUTH CENTRAL KANSAS AS MID LEVEL MOISTURE WRAPS AROUND IT
BRINGING AN INCREASE IN CLOUDS. SOME PRECIPITATION WILL BE POSSIBLE
ACROSS WICHITA`S FORECAST AREA DURING THIS TIME FRAME BUT HAVE
ELECTED TO LEAVE IT OUT OF OUR FORECAST AREA FOR THE TIME BEING.
FARTHER WEST, AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BE BUILDING
ACROSS THE ROCKIES FRIDAY THROUGH SUNDAY. A DOME OF HIGH PRESSURE
WILL BE FOUND ACROSS THIS AREA AT THE SURFACE, AND WITH THE
ATMOSPHERIC COULOMB BEING FAIRLY DRY, PARTLY CLOUDY SKIES AND DRY
CONDITIONS ARE FORECASTED ACROSS THE REMAINDER OF THE CWA. WINDS
FRIDAY THROUGH SATURDAY NIGHT WILL GENERALLY BE FROM THE NORTH TO
NORTHWEST SHIFTING TO THE NORTHEAST ON SUNDAY.
MEANWHILE, AN UPPER LEVEL LOW WILL BE FORMING ACROSS THE DESERT
SOUTHWEST AND EASTERN PACIFIC OCEAN FRIDAY THROUGH SUNDAY. THIS LOW
IS THEN ANTICIPATED TO SHIFT EASTWARD DURING THE BEGINNING OF NEXT
WEEK AND FLATTEN OUT THE UPPER LEVEL RIDGE. AS THIS SYSTEM
APPROACHES, LEE TROUGHING WILL DEVELOP SHIFTING WINDS TO THE SOUTH
AND BRINGING BACK MID TO LOW LEVEL MOISTURE TO WESTERN KANSAS.
THUNDERSTORM CHANCES INCREASE MONDAY NIGHT INTO THE MIDDLE PART OF
NEXT WEEK. HOWEVER, WITH THIS SYSTEM BEING OUT ON DAY 6 AND 7,
CHANGES WILL MOST LIKELY BE MADE AS FUTURE MODEL RUNS BRING IN
DIFFERENT SOLUTIONS.
AS FOR TEMPERATURES, A GENERAL WARM UP IS EXPECTED THIS WEEKEND INTO
THE BEGINNING OF NEXT WEEK. HIGHS START OUT IN THE 50S AND LOWER 60S
FRIDAY AFTERNOON THEN INCREASE INTO THE 70S BY EARLY NEXT WEEK. LOWS
START OUT IN THE 30S SATURDAY MORNING THEN INCREASE INTO THE UPPER
40S AND LOWER 50S BY TUESDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1200 AM CDT THU MAY 2 2013
POOR FLIGHT CONDITIONS WITH IFR CIGS EXPECTED THROUGH THE OVERNIGHT
HOURS IN ASSOCIATION WITH -SN AND LOW STRATUS. SYSTEM WILL EXIT OUT
OF THE REGION THROUGH THE AFTERNOON WITH FLIGHT CONDITIONS IMPROVING
WITH TIME. WINDS WILL BE NORTHERLY 20-30 KT THROUGH MOST OF THE TAF
PD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 27 56 34 / 50 0 10 10
GCK 47 26 58 33 / 30 0 0 10
EHA 46 27 60 36 / 30 0 0 0
LBL 46 25 59 35 / 50 0 0 0
HYS 47 27 52 34 / 40 0 10 20
P28 44 31 54 36 / 100 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING FROM 11 PM CDT /10 PM MDT/ THIS EVENING TO 1
PM CDT /NOON MDT/ FRIDAY FOR KSZ030-031-043>046-061>065-074>078-
084>087.
WINTER WEATHER ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ030-
043>045.
FREEZE WARNING UNTIL 10 AM CDT /9 AM MDT/ THIS MORNING FOR
KSZ030-031-043>046-061>065-074>080-084>088.
FREEZE WARNING FROM 11 PM THIS EVENING TO 1 PM CDT FRIDAY FOR
KSZ066-079>081-088>090.
WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR KSZ085>090.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...HOVORKA_42
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1018 PM EDT FRI MAY 3 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN CENTERED FROM NEW ENGLAND TO THE
CANADIAN MARITIMES THROUGH WEEKEND. THE PROLONGED ONSHORE FLOW
WILL RESULT IN A VARYING AMOUNT OF CLOUDINESS AND BELOW NORMAL
TEMPERATURES. A SLOW MOVING UPPER LEVEL SYSTEM WILL BRING
INCREASING MOISTURE AND A HIGH CHANCE FOR RAIN FROM SUNDAY NIGHT
THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE LATEST SURFACE ANALYSIS SHOWS A ~1032MB HIGH CENTERED OVER
ATLANTIC CANADA...WITH A SURFACE RIDGE AXIS EXTENDING SW ACROSS
NEW ENGLAND AND INTO THE PIEDMONT. THIS COMBINED WITH A 1004MB LOW
OVER FL HAS HELPED MAINTAIN ENE ONSHORE FLOW ACROSS THE LOCAL AREA
UNDERNEATH A STRONG OMEGA BLOCK. THE SKY IS GENERALLY PARTLY TO
MOSTLY CLOUDY UNDER A CIRRUS SHIELD WITH A SC DECK OVER THE ATLANTIC
ENCROACHING ON COASTAL AREAS. EVENTUALLY LOW CLOUDS ARE EXPECTED
TO OVERSPREAD MOST OF THE AREA AFTER 06Z. AS WITH PREVIOUS FEW
NIGHTS THINK FOG WILL BE FAIRLY LIMITED IN COVERAGE WITH LOW
CLOUDS BEING MORE DOMINANT SO WILL NOT MENTION IN THE GRIDDED
FCST. LOWS MAINLY 45-50.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
STRONG OMEGA BLOCKING PATTERN WILL DOMINATE THE SHORT TERM
PERIOD...WITH A SLOW PROGRESSION OF THE UPSTREAM TROUGH MOVING E
FROM THE LWR MS VALLEY ON SAT TO AL/GA BY MONDAY. RIDGE ALOFT RMNS
IN PLACE FROM THE NRN LAKES TO NEW ENG THROUGH THIS TIMEFRAME.
IN TERMS OF SENSIBLE WX...NOT TOO MUCH CHANGE FROM THE PAST 2 DAYS
FOR SAT/SUN WITH CONTINUED ENE FLOW AND COOLISH TEMPERATURES. IT
DOES LOOK LIKE CLOUD COVER WILL BE A BIT MORE WIDESPREAD SAT
MORNING...AND SLOWER TO SCATTER OUT THROUGH THE DAY. WILL GO WITH
MOSTLY CLOUDY SKIES THROUGH EARLY AFTN...PARTLY SUNNY LATE. HIGHS A
TAD COOLER AS WELL...GENLY MID-UPPER 60S WELL INLAND (UPPER 50S TO
LOWER 60S NEAR THE IMMEDIATE COAST). NOT RULING OUT ISOLD SHRAS SAT
MRNG...BUT WILL KP AOB 14% FOR NOW. BY SUNDAY...THE SLOW MOVING
UPPER LOW FM W OF THE MTNS MAKES IT FAR ENOUGH EAST TO LEAD TO
INCREASING DEEPER MOISTURE BY AFTN...ENOUGH TO INCLUDE SOME LOW CHC
POPS IN THE FCST OVER SOUTH CENTRAL VA BY LATE AFTN...GENLY JUST
BECOMING MOSTLY CLOUDY ELSEWHERE (MORE SUN ACRS N/E ZONES THROUGH
AFTN). HI TEMPS SUN FROM THE U50S TO L60S AT THE CST TO THE MID-
UPPER 60S INLAND (ALTHOUGH A TAD COOLER OVER THE WRN ZONES WHERE
CLOUDS THICKEN/LOWER EARLIEST). DEEP MOISTURE AND OVERRUNNING
BEGINS IN EARNEST LATER SUN NIGHT/MON. NAM SOLUTION IS A SLOW
OUTLIER AND HAS GENLY BENN DISREGARDED IN FAVOR OF GFS/ECMWF
CONSENSUS. THUS..HAVE LIKELY POPS OVERSPREADING THE REGION FROM
WSW TO ENE WITH ALL AREAS EXPECTING RAIN BY MON AFTN. OVC/LOW
CLOUDS MON WILL HOLD HIGH TEMPS 60-65 OVER MOST OF THE REGION
(UPPER 60S SE VA/NE NC AWAY FROM THE IMMEDIATE COAST).
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A PESKY UPPER LOW WILL MEANDER ACROSS THE SERN STATES MONDAY NIGHT
BEFORE MOVING NORTHWARD ALONG THE CAROLINA COAST TUESDAY. THE UPPER
LOW THEN MOVES OUT TO SEA OFF THE MID-ATLANTIC COAST WEDNESDAY
BEFORE CONTINUE TO MOVE NORTHWARD ALONG THE NEW ENGLAND COAST
THURSDAY INTO NEXT FRIDAY. BASED ON GOOD MODEL AGREEMENT...HAVE
INCREASED TO LIKELY POPS (60-70%) ACROSS THE LOCAL AREA MONDAY NIGHT
AND TUESDAY AS A NICE DEFORMATION ZONE IS SHOWN TO SET UP OVER THE
REGION. WITH THE LOW PASSING TO THE EAST TUESDAY NIGHT/WEDNESDAY...
WILL MAINTAIN SOLID CHANCE ACROSS THE REGION. A BRIEF REPRIEVE FROM
THE WET WEATHER LOOKS LIKE IT COULD RETURN BY NEXT THURSDAY/FRIDAY
AS THE LOW HEADS NE AND A WEAK H5 RIDGE BUILDS OVER THE
MID-ATLANTIC. TEMPS WILL REMAIN COOLER THAN NORMAL THROUGH WEDNESDAY
DUE TO THE WET WEATHER AND ABUNDANT CLOUD COVER. A RETURN TO NEAR-
OR SLIGHTLY-ABOVE-NORMAL TEMPS LOOKS POSSIBLE NEXT THURSDAY/FRIDAY
IF WE ARE IN FACT ABLE TO DRY OUT. HIGHS TUESDAY/WEDNESDAY MAINLY IN
THE 60S TO LOW 70S. HIGHS THURSDAY IN THE UPR 60S TO UPR 70S. HIGHS
NEXT FRIDAY IN THE 70S TO LOW 80S. MIN TEMPS MAINLY IN THE 50S
THROUGH THE PERIOD.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE REMAINS ANCHORED ALONG THE NE AND MID ATLANTIC
COASTS...RESULTING IN CONTINUED ONSHORE E/NE FLOW. CLOUDS EXPECTED
TO INCREASE OVER THE REGION AS LOW LEVEL MOISTURE FROM THE ATL
ADVECTS ONSHORE. CIGS WILL RANGE FROM 3-4KFT INITIALLY AND
GRADUALLY LOWER TO AROUND 1-2KFT OVERNIGHT WITH CHC FOR SOME IFR
CIGS BY DAYBREAK. MVFR CIGS EXPECTED TO PUSH AS FAR WWD AS
INTERSTATE 95 BY LATE THIS EVENING. MODELS HAVE STRUGGLED HANDLING
LOW STRATUS/POSSIBLE IFR CIGS THE LAST SEVERAL NIGHTS. LATEST
RAP/SREF GUIDANCE SUGGESTS IFR CIGS AS FAR INLAND AS THE ERN VA
PIEDMONT WHILE THE NAM/GFS ARE NOT AS ROBUST. TRENDED TAFS TOWARD
THE LATEST RAP GUIDANCE AS IT HAS PERFORMED RELATIVELY WELL THE
LAST COUPLE OF NIGHTS. ONLY MENTIONED IFR CIGS AT KSBY ATTM...BUT
ADDITIONAL IFR WILL BE POSSIBLE. BREEZY E/NE WINDS 10 TO 15 KT
AND GUSTS TO 20 KT ESP ALONG THE COAST EARLY TONIGHT BEFORE
DIMINISHING LATER TONIGHT...GENERALLY AOB 15 KT.
OUTLOOK: SIMILAR PATTERN CONTINUES THROUGH THE WEEKEND WITH
STRONG HIGH PRESSURE NOSING INTO THE MID ATLANTIC AND E/NE FLOW
OVER THE AREA. WHICH COULD LEAD TO PERIODS OF LOW STRATUS CLOUDS
OF MVFR TO IFR LEVELS EACH NIGHT. EARLY NEXT WEEK...AN ANOMALOUSLY
STRONG UPPER LOW IS EXPECTED TO MOVE INTO THE SOUTHEASTERN
US...WHICH COULD PRODUCE WIDESPREAD RAIN WITH MVFR TO IFR
CONDITIONS MONDAY INTO TUESDAY.
&&
.MARINE...
AN UPPER LOW WELL OFFSHORE WILL REMAIN WELL OFFSHORE AS IT DIVES
S-SW THROUGH TONIGHT. MEANWHILE...A DEVELOPING LOW OFF THE ATLANTIC
COAST OF FLORIDA DRIFTS NORTHEAST...HELPING TO MAINTAIN THE TIGHT
PRESSURE GRADIENT FOR MUCH OF THE MARINE AREA THROUGH TONIGHT. WINDS
ARE EXPECTED TO SUBSIDE ON THE RIVERS AND THE CENTRAL CHESAPEAKE BAY
BY LATE THIS EVENING AND TONIGHT...THUS HAVE HEADLINES ENDING IN THESE
AREA AT 10 PM AND 1 AM RESPECTIVELY.
MODERATE E-NE FLOW CONTINUES SATURDAY THANKS TO A STRONG SFC HIGH
ALONG THE NEW ENGLAND COAST AND LOW PRESSURE OVER THE DEEP SOUTH.
WINDS ARE NOT EXPECTED TO BE AS STRONG AS TODAY ON THE RIVERS AND
THE CENTRAL CHESAPEAKE BAY...THUS WILL NOT CARRY ANY SCA`S IN THESE
AREAS FOR SATURDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT SUNDAY FOR ANZ634-650-652-
654-656-658.
SMALL CRAFT ADVISORY UNTIL 7 PM EDT SATURDAY FOR ANZ632.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT SATURDAY FOR ANZ633.
SMALL CRAFT ADVISORY UNTIL 1 AM EDT SATURDAY FOR ANZ630-631.
&&
$$
SYNOPSIS...LKB
NEAR TERM...AJZ/LKB
SHORT TERM...LKB
LONG TERM...JDM
AVIATION...SAM/JEF
MARINE...JDM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
924 PM EDT FRI MAY 3 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN CENTERED FROM NEW ENGLAND TO THE
CANADIAN MARITIMES THROUGH WEEKEND. THE PROLONGED ONSHORE FLOW
WILL RESULT IN A VARYING AMOUNT OF CLOUDINESS AND BELOW NORMAL
TEMPERATURES. A SLOW MOVING UPPER LEVEL SYSTEM WILL BRING
INCREASING MOISTURE AND A HIGH CHANCE FOR RAIN FROM SUNDAY NIGHT
THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
MAINLY CLR THIS EVENING AFTER DIURNAL CU DISSIPATES...BUT WITH LOW
CLOUDS ONCE AGAIN EXPECTED AFTER MIDNIGHT. AS W/ PREV FEW NIGHTS
THINK FOG WILL BE FAIRLY LIMITED IN COVERAGE WITH LOW CLOUDS
BEING MORE DOMINANT SO WILL NOT MENTION IN THE GRIDDED FCST. LOWS
MAINLY 45-50.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
STRONG OMEGA BLOCKING PATTERN WILL DOMINATE THE SHORT TERM
PERIOD...WITH A SLOW PROGRESSION OF THE UPSTREAM TROUGH MOVING E
FROM THE LWR MS VALLEY ON SAT TO AL/GA BY MONDAY. RIDGE ALOFT RMNS
IN PLACE FROM THE NRN LAKES TO NEW ENG THROUGH THIS TIMEFRAME.
IN TERMS OF SENSIBLE WX...NOT TOO MUCH CHANGE FROM THE PAST 2 DAYS
FOR SAT/SUN WITH CONTINUED ENE FLOW AND COOLISH TEMPERATURES. IT
DOES LOOK LIKE CLOUD COVER WILL BE A BIT MORE WIDESPREAD SAT
MORNING...AND SLOWER TO SCATTER OUT THROUGH THE DAY. WILL GO WITH
MOSTLY CLOUDY SKIES THROUGH EARLY AFTN...PARTLY SUNNY LATE. HIGHS A
TAD COOLER AS WELL...GENLY MID-UPPER 60S WELL INLAND (UPPER 50S TO
LOWER 60S NEAR THE IMMEDIATE COAST). NOT RULING OUT ISOLD SHRAS SAT
MRNG...BUT WILL KP AOB 14% FOR NOW. BY SUNDAY...THE SLOW MOVING
UPPER LOW FM W OF THE MTNS MAKES IT FAR ENOUGH EAST TO LEAD TO
INCREASING DEEPER MOISTURE BY AFTN...ENOUGH TO INCLUDE SOME LOW CHC
POPS IN THE FCST OVER SOUTH CENTRAL VA BY LATE AFTN...GENLY JUST
BECOMING MOSTLY CLOUDY ELSEWHERE (MORE SUN ACRS N/E ZONES THROUGH
AFTN). HI TEMPS SUN FROM THE U50S TO L60S AT THE CST TO THE MID-
UPPER 60S INLAND (ALTHOUGH A TAD COOLER OVER THE WRN ZONES WHERE
CLOUDS THICKEN/LOWER EARLIEST). DEEP MOISTURE AND OVERRUNNING
BEGINS IN EARNEST LATER SUN NIGHT/MON. NAM SOLUTION IS A SLOW
OUTLIER AND HAS GENLY BENN DISREGARDED IN FAVOR OF GFS/ECMWF
CONSENSUS. THUS..HAVE LIKELY POPS OVERSPREADING THE REGION FROM
WSW TO ENE WITH ALL AREAS EXPECTING RAIN BY MON AFTN. OVC/LOW
CLOUDS MON WILL HOLD HIGH TEMPS 60-65 OVER MOST OF THE REGION
(UPPER 60S SE VA/NE NC AWAY FROM THE IMMEDIATE COAST).
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A PESKY UPPER LOW WILL MEANDER ACROSS THE SERN STATES MONDAY NIGHT
BEFORE MOVING NORTHWARD ALONG THE CAROLINA COAST TUESDAY. THE UPPER
LOW THEN MOVES OUT TO SEA OFF THE MID-ATLANTIC COAST WEDNESDAY
BEFORE CONTINUE TO MOVE NORTHWARD ALONG THE NEW ENGLAND COAST
THURSDAY INTO NEXT FRIDAY. BASED ON GOOD MODEL AGREEMENT...HAVE
INCREASED TO LIKELY POPS (60-70%) ACROSS THE LOCAL AREA MONDAY NIGHT
AND TUESDAY AS A NICE DEFORMATION ZONE IS SHOWN TO SET UP OVER THE
REGION. WITH THE LOW PASSING TO THE EAST TUESDAY NIGHT/WEDNESDAY...
WILL MAINTAIN SOLID CHANCE ACROSS THE REGION. A BRIEF REPRIEVE FROM
THE WET WEATHER LOOKS LIKE IT COULD RETURN BY NEXT THURSDAY/FRIDAY
AS THE LOW HEADS NE AND A WEAK H5 RIDGE BUILDS OVER THE
MID-ATLANTIC. TEMPS WILL REMAIN COOLER THAN NORMAL THROUGH WEDNESDAY
DUE TO THE WET WEATHER AND ABUNDANT CLOUD COVER. A RETURN TO NEAR-
OR SLIGHTLY-ABOVE-NORMAL TEMPS LOOKS POSSIBLE NEXT THURSDAY/FRIDAY
IF WE ARE IN FACT ABLE TO DRY OUT. HIGHS TUESDAY/WEDNESDAY MAINLY IN
THE 60S TO LOW 70S. HIGHS THURSDAY IN THE UPR 60S TO UPR 70S. HIGHS
NEXT FRIDAY IN THE 70S TO LOW 80S. MIN TEMPS MAINLY IN THE 50S
THROUGH THE PERIOD.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE REMAINS ANCHORED ALONG THE NE AND MID ATLANTIC
COASTS...RESULTING IN CONTINUED ONSHORE E/NE FLOW. CLOUDS EXPECTED
TO INCREASE OVER THE REGION AS LOW LEVEL MOISTURE FROM THE ATL
ADVECTS ONSHORE. CIGS WILL RANGE FROM 3-4KFT INITIALLY AND
GRADUALLY LOWER TO AROUND 1-2KFT OVERNIGHT WITH CHC FOR SOME IFR
CIGS BY DAYBREAK. MVFR CIGS EXPECTED TO PUSH AS FAR WWD AS
INTERSTATE 95 BY LATE THIS EVENING. MODELS HAVE STRUGGLED HANDLING
LOW STRATUS/POSSIBLE IFR CIGS THE LAST SEVERAL NIGHTS. LATEST
RAP/SREF GUIDANCE SUGGESTS IFR CIGS AS FAR INLAND AS THE ERN VA
PIEDMONT WHILE THE NAM/GFS ARE NOT AS ROBUST. TRENDED TAFS TOWARD
THE LATEST RAP GUIDANCE AS IT HAS PERFORMED RELATIVELY WELL THE
LAST COUPLE OF NIGHTS. ONLY MENTIONED IFR CIGS AT KSBY ATTM...BUT
ADDITIONAL IFR WILL BE POSSIBLE. BREEZY E/NE WINDS 10 TO 15 KT
AND GUSTS TO 20 KT ESP ALONG THE COAST EARLY TONIGHT BEFORE
DIMINISHING LATER TONIGHT...GENERALLY AOB 15 KT.
OUTLOOK: SIMILAR PATTERN CONTINUES THROUGH THE WEEKEND WITH
STRONG HIGH PRESSURE NOSING INTO THE MID ATLANTIC AND E/NE FLOW
OVER THE AREA. WHICH COULD LEAD TO PERIODS OF LOW STRATUS CLOUDS
OF MVFR TO IFR LEVELS EACH NIGHT. EARLY NEXT WEEK...AN ANOMALOUSLY
STRONG UPPER LOW IS EXPECTED TO MOVE INTO THE SOUTHEASTERN
US...WHICH COULD PRODUCE WIDESPREAD RAIN WITH MVFR TO IFR
CONDITIONS MONDAY INTO TUESDAY.
&&
.MARINE...
AN UPPER LOW WELL OFFSHORE WILL REMAIN WELL OFFSHORE AS IT DIVES
S-SW THROUGH TONIGHT. MEANWHILE...A DEVELOPING LOW OFF THE ATLANTIC
COAST OF FLORIDA DRIFTS NORTHEAST...HELPING TO MAINTAIN THE TIGHT
PRESSURE GRADIENT FOR MUCH OF THE MARINE AREA THROUGH TONIGHT. WINDS
ARE EXPECTED TO SUBSIDE ON THE RIVERS AND THE CENTRAL CHESAPEAKE BAY
BY LATE THIS EVENING AND TONIGHT...THUS HAVE HEADLINES ENDING IN THESE
AREA AT 10 PM AND 1 AM RESPECTIVELY.
MODERATE E-NE FLOW CONTINUES SATURDAY THANKS TO A STRONG SFC HIGH
ALONG THE NEW ENGLAND COAST AND LOW PRESSURE OVER THE DEEP SOUTH.
WINDS ARE NOT EXPECTED TO BE AS STRONG AS TODAY ON THE RIVERS AND
THE CENTRAL CHESAPEAKE BAY...THUS WILL NOT CARRY ANY SCA`S IN THESE
AREAS FOR SATURDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT SUNDAY FOR ANZ634-650-652-
654-656-658.
SMALL CRAFT ADVISORY UNTIL 7 PM EDT SATURDAY FOR ANZ632.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT SATURDAY FOR ANZ633.
SMALL CRAFT ADVISORY UNTIL 1 AM EDT SATURDAY FOR ANZ630-631.
&&
$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB
LONG TERM...JDM
AVIATION...SAM/JEF
MARINE...JDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1142 PM EDT FRI MAY 3 2013
.SYNOPSIS...
ISSUED AT 329 PM EDT FRI MAY 3 2013
UNSEASONABLY WARM TEMPERATURES WILL PERSIST THROUGH THE WEEKEND INTO
EARLY NEXT WORK WEEK. EAST WINDS WILL KEEP TEMPERATURES WARM ALL
THE WAY TO THE LAKE SHORE. THE NEXT GOOD CHANCES FOR RAIN DO NOT
ARRIVE UNTIL WEDNESDAY NIGHT INTO THURSDAY.
&&
.UPDATE...
ISSUED AT 522 PM EDT FRI MAY 3 2013
I UPDATED THE GRIDS TO BETTER MATCH THE TEMP/DEW POINT GRADIENT
NEAR US-31 OVER THE NEXT FEW HOURS. I ALSO USING A COMBINATION OF
THE HRRR 19Z AND RAP MODEL UPDATED THE POP/WEATHER GRIDS TO SHOW
THE SHOWERS LIFTING OUT TO THE NORTHWEST OVER THE NEXT FEW HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 329 PM EDT FRI MAY 3 2013
CONVECTION HAS RECENTLY DEVELOPED ALONG THE INVERTED TROUGH/LAKE
BREEZE BOUNDARY IN A REGION OF BETTER INSTABILITY CENTERED MAINLY
SOUTH OF MUSKEGON. EXPECT A RAPID DECREASE IN ACTIVITY AGAIN THIS
EVENING WITH A LOSS OF INSOLATION.
AFTER THIS EVENING...DRY CONDITIONS WITH EAST WINDS WILL PERSIST
THROUGH THE WEEKEND. THIS IS A WARM AND DRY PATTERN SO WENT ABOVE
GUIDANCE TEMPERATURES...ESPECIALLY ALONG THE LAKESHORE WHICH CAN
WARM SIGNIFICANTLY WITH THIS TYPE OF PATTERN WHERE SLIGHT
DOWNSLOPING COMES INTO PLAY.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM EDT FRI MAY 3 2013
HAVE A DRY FORECAST FROM MONDAY THROUGH WEDNESDAY NIGHT AS THE LOW
OVER THE SOUTHEAST U.S. AIDES IN KEEPING A RIDGE OVER THE GREAT
LAKES. DRY AND WARM WEATHER IS FORECAST TO CONTINUE WITH HIGHS NEAR
70 OR INTO THE LOWER 70S EACH DAY NEXT WEEK. THE NEXT CHANCE FOR
PRECIPITATION COMES OUT ON THURSDAY WHEN AN UPPER SHORTWAVE TROUGH
IS PROGD TO SLIP THROUGH THE AREA. GIVEN UPPER LOWS SITUATED OVER
THE LOWER 48 AND THE SHORTWAVE IS ON THE SOUTHERN EDGE OF THE
WESTERLIES...CONFIDENCE IS LOWER IN ITS PLACEMENT AT DAY 6 IN THE
FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1141 PM EDT FRI MAY 3 2013
VFR CIGS OVER 10000 FT AGL ARE EXPECTED THROUGH SATURDAY. WINDS
WILL BECOME GUSTY FROM THE SOUTHEAST DURING SATURDAY AFTERNOON.
&&
.MARINE...
ISSUED AT 329 PM EDT FRI MAY 3 2013
NO CHANGES TO THE FORECAST PLANNED AT THIS TIME. AFTER WINDS AND
WAVES SUBSIDE THIS EVENING...GENERALLY LIGHT OFFSHORE WINDS WILL
PRECLUDE THE NEED FOR HEADLINES.
&&
.FIRE WEATHER...
ISSUED AT 329 PM EDT FRI MAY 3 2013
WITH EASTERLY WINDS OVER THE WEEKEND...WE ARE IN A FAVORABLE SETUP
FOR WARM AND DRY CONDITIONS. THE LATEST PLANNING FORECAST
ISSUANCE BRINGS SOME AREAS CLOSER TO RED FLAG WARNING CRITERIA.
TEMPERATURE AND HUMIDITY THRESHOLDS WILL BE SOMETHING TO CLOSELY
WATCH OVER THE NEXT COUPLE DAYS. HOWEVER...WIND SPEEDS SHOULD ALSO
BE DECREASING FROM SATURDAY TO SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 329 PM EDT FRI MAY 3 2013
NO CONCERNS DUE TO LITTLE OR NO EXPECTED PRECIPITATION OVER THE
NEXT SEVERAL DAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...TJT
SHORT TERM...TJT
LONG TERM...DUKE
AVIATION...WDM
FIRE WEATHER...TJT
HYDROLOGY...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
739 PM EDT FRI MAY 3 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 418 PM EDT FRI MAY 3 2013
UPPER TROUGH CONTINUES TO SPLIT APART NEXT 24 HRS WITH UPPER LOW
FOCUSING OVER CNTRL MISSISSIPPI RIVER VALLEY. REGIONAL RADAR SHOWS
SWATH OF MAINLY RAIN FROM ILLINOIS INTO WISCONISN AND INTO WESTERN
UPR MICHIGAN AND INTO MINNESOTA ARROWHEAD. THIS PRECIP IS SUPPORTED
BY PERSISTENT H85-H7 FRONTOGENESIS AND RIGHT ENTRANCE REGION FROM
UPPER JET OVER ONTARIO. BOTH FEATURES ARE FORECAST TO DIMINISH INTO
SATURDAY AS UPPER LOW TO THE SOUTH BECOMES DOMINANT UPPER LEVEL
FEATURE.
ANALYSIS FROM RUC AND NAM INDICATING WARM LAYER IS WELL ABOVE 0C
SUGGESTS PTYPE OVER WESTERN UPR MICHIGAN SHOULD BE RAIN BUT REPORTS
FROM GOGEBIC INTO SOUTHERN HOUGHTON COUNTY SHOW IT IS NOT WITH LGT
SNOW OCCURRING. THESE AREAS LINE UP WELL WITH SUB ZERO 950-900MB
TEMPS SO KEPT MENTION OF SLEET/SNOW OVER FAR WESTERN UPR MICHIGAN
THROUGH EARLY MORNING HOURS BEFORE SHALLOWER COLD TEMPS WARM ABOVE
0C. OTHERWISE...RAIN WILL BE DOMINANT PTYPE ACROSS REST OF
CWA...MORE SCATTERED IN THE EASTERN HALF OF CWA. KEPT A MENTION OF
FZRA OVER INLAND WESTERN THIRD OF CWA. SINCE MAJORITY OF PRECIP WILL
OCCUR OVER WESTERN CWA AND SINCE THERE IS GOING TO BE CONTINUING
FZRA/SLEET/SNOW...CHANGING TO RAIN/FREEZING RAIN...OPTED TO KEEP
WINTER WEATHER ADVY OUT FOR GOGEBIC AND ONTONAGON COUNTIES THROUGH
12Z SATURDAY. COULD SEE SIMILAR PYTPE THIS EVENING FARTHER EAST
ACROSS KEWEENAW...BUT BASED ON UPSTREAM RADAR TRENDS AND BLEND OF
SHORT TERM MODELS...THINK THESE AREAS WILL MISS OUT ON HEAVIER QPF
AND BETTER CHANCE OF SLEET/ICE ACCUMS.
IMPROVING WEATHER ON SATURDAY...HOPEFULLY. LINGERING DIVERGENCE
ALOFT MAY STILL BRING SOME LGT RAIN OVER WEST AND NORTHWEST CWA.
SHOULD STAY DRY OVER THE EAST HALF. SIMILAR TO LAST COUPLE DAYS
SHOULD BE A WIDE TEMPERATURE RANGE FROM WEST TO EAST. BASED ON FCST
H85 TEMPS AND CLEARER SKIES EXPECTED...THINKING EASTERN INTERIOR
CWA MAY REACH MID 60S TO LOWER 70S. COOLER NORTH FLOW KEEPS WEST AND
CNTRL COOLER...BUT STILL A BIT WARMER THAN RECENT TEMPERATURES.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 418 PM EDT FRI MAY 3 2013
NAM SHOWS A CLOSED 500 MB LOW OVER NORTHERN CA AND ANOTHER OVER
NORTHERN ARKANSAS WITH A 500 MB RIDGE OVER THE LOWER GREAT LAKES.
THE 500 MB PATTERN OVER THE EAST HALF OF THE U.S. IS AN OMEGA BLOCK
00Z SUN AND DOES NOT MOVE MUCH ON SUNDAY EXCEPT TO TRY TO FORM A REX
BLOCK WITH THE LOW MOVING SLOWLY EAST UNDERNEATH THE RIDGE. THE REX
BLOCK THEN GETS ESTABLISHED ON MON. THIS FORECAST PERIOD FEATURES
DEEPER MOISTURE OVER THE WEST HALF OF THE CWA GRADUALLY DECREASING.
WILL KEEP SLIGHT CHANCE POPS OVER THE FAR WESTERN CWA SAT NIGHT WITH
THIS MOVING FURTHER WEST WITH TIME ON SUN. PCPN SHOULD BE ALL RAIN
BY THAT TIME. TEMPERATURES CONTINUE THE SLOW WARMING TREND WITH TIME
AND DRY WEATHER COMES IN FOR SUN INTO MON. DID NOT MAKE TOO MANY
CHANGES TO THE GOING FORECAST FOR TEMPERATURES EXCEPT DID LOWER LOWS
A BIT WITH THE COLDER MOS GUIDANCE FOR SAT NIGHT AND SUN NIGHT.
IN THE EXTENDED...ECMWF AND GFS SHOW A CLOSED 500 MB LOW OVER THE
SOUTHEAST U.S. 12Z TUE. THINGS GET INTERESTING OVER THE NORTHERN
PLAINS. 12Z TUE...ECMWF HAS A CLOSED 500 MB LOW NEAR SISSETON SD AND
THE GFS HAS A 500 MB RIDGE THERE INSTEAD. THIS DIFFERENCE CARRIES
INTO 12Z WED WITH THE ECMWF CONTINUING ITS SOLUTION OF A TROUGH IN
THE UPPER MISSISSIPPI VALLEY WITH THE 06Z GFS HAVING A CLOSED 500 MB
LOW OVER MISSOURI WHILE THE 00Z GFS STILL MAINTAINING A RIDGE OVER
THE CORNBELT. THE ECMWF TAKES THE TROUGH INTO THE UPPER GREAT LAKES
12Z THU WITH THE GFS MAINTAINING A FLAT 500 MB RIDGE OVER THE AREA.
THE 500 MB RIDGE GETS FLATTENED BY 12Z FRI WITH A BROAD 500 MB
TROUGH AND THE WESTERLIES GETTING PUSHED SOUTH INTO THE AREA.
CONFIDENCE REMAINS LOW WITH THIS EXTENDED FORECAST DUE TO THE 2 VERY
DIFFERENT MODEL SOLUTIONS. LOOKS DRY THROUGH TUE NIGHT BEFORE A COLD
FRONT HEADS SOUTH OUT OF CANADA AND BRINGS WITH IT A SLIGHT CHANCE
TO LOW CHANCE FOR PCPN WED INTO FRI. TEMPERATURES CONTINUE TO SLOWLY
WARM AND GO TO NEAR NORMAL BY THE END OF THE PERIOD. THE COLD FRONT
MOVES THROUGH WED NIGHT AND SLOWLY PUSHES SOUTH OF THE AREA THEN FOR
THU INTO FRI.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 737 PM EDT FRI MAY 3 2013
ABUNDANT LOW-LEVEL MOISTURE WILL LIKELY LINGER THRU MUCH OF THIS
FCST PERIOD. AS A RESULT...KIWD WILL LIKELY REMAIN UNDER IFR
CONDITIONS THRU SAT AFTN. EXPECT OCNL -FZDZ/-FZRA AT KIWD TONIGHT
CHANGING TO -SHRA SAT MORNING AS TEMPS RISE. AT KCMX...IFR
CONDITIONS WILL LIKELY PREVAIL THRU SAT MORNING. MAY SEE SOME
IMPROVEMENT TO LOW MVFR SAT AFTN. EXPECT OCNL -FZDZ TO TRANSITION TO
OCNL -DZ AT KCMX LATE TONIGHT. AT KSAW...UPSLOPE NORTHERLY WINDS
WILL PROBABLY WORK TO MAINTAIN LIFR CONDITIONS TONIGHT. NOT OUT OF
THE QUESTION THAT FOG MAY BECOME DENSE WITH VIS DROPPING TO VLIFR
TONIGHT. MAY SEE SOME -DZ/-SHRA AT TIMES. DRIER AIR MAY MAKE INROADS
INTO THE AREA SAT AFTN...AND THIS MAY ALLOW KSAW TO IMPROVE TO MVFR
PERHAPS EVEN VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 PM EDT FRI MAY 3 2013
NO GALES SEEN DURING THIS FORECAST PERIOD. THE STRONGEST WINDS IN
THE PERIOD ARE THIS AFTERNOON WITH NORTHEAST WINDS BELOW 25 KNOTS. A
HIGH PRESSURE RIDGE SETTLES IN AND KEEPS STRONG SYSTEMS AWAY FROM
THE AREA.
&&
.HYDROLOGY...
ISSUED AT 418 PM EDT FRI MAY 3 2013
STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER AROUND
WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL REMAIN
CONCERNS INTO AT LEAST EARLY NEXT WEEK...BUT OTHERWISE RIVER LEVELS
CONTINUE TO COME DOWN. ACTUALLY...MICHIGAMME MAY REMAIN A CONCERN
THROUGH MOST OF NEXT WEEK. DECENT AMOUNT OF WATER EQUIVALENT HAS
OCCURRED LAST TWO DAYS OVER WESTERN CWA...VCNTY OF IRONWOOD TO
ONTONAGON...OVER 2 INCHES OVER FAR WESTERN GOGEBIC COUNTY. WILL HAVE
TO ASSESS WHAT AFFECT THE PRECIP WILL HAVE WHEN COMBINED WITH
FURTHER MELTING OF ANY SUSTAINED SNOWPACK WHEN TEMPS WARM INTO THE
60-70S SUN INTO NEXT WEEK. SNOW WATER EQUIVALENT OF 8.8 INCHES IN
PAINESDALE ON THURSDAY WITH 24 INCHES OF SNOW DEPTH...SO THE OTTER
RIVER STILL HAS PLENTY OF SNOW IN THE HEADWATERS WHICH MAY CAUSE
ADDITIONAL PROBELMS AT CLLM4 IN THE COMING DAYS.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ SATURDAY FOR
MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...ROLFSON
MARINE...07
HYDROLOGY...JLA
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
214 PM EDT THU MAY 2 2013
.SYNOPSIS...
ISSUED AT 421 AM EDT THU MAY 2 2013
A STRONG LOW PRESSURE SYSTEM WILL TAKE SHAPE ACROSS THE CENTRAL
PLAINS AND MID MISSISSIPPI VALLEY THROUGH THE WEEKEND...AS UPPER
LEVEL HIGH PRESSURE REMAINS PARKED ACROSS THE GREAT LAKES AND
NORTHEAST STATES. THIS WEATHER PATTERN WILL YIELD CONTINUED MILD
TEMPERATURES RIGHT ON THROUGH THE WEEKEND...WITH JUST A FEW SMALL
CHANCES FOR MAINLY AFTERNOON RAIN SHOWERS. DRY BUT CONTINUED WARM
WEATHER IS EXPECTED FOR MUCH OF NEXT WEEK...AS HIGH PRESSURE REMAINS
IN CONTROL ACROSS THE GREAT LAKES.
&&
.UPDATE...
ISSUED AT 211 PM EDT THU MAY 2 2013
DEWPOINTS QUICKLY MIXING OUT FROM GLR-GOV-MIO ALLOWING RH/S TO
REACH BELOW 30 PERCENT. THIS...COMBINED WITH TEMPERATURES NEAR 80
HAS RESULTED IN ELEVATED FIRE DANGER /WINDS NOT QUITE TO RED FLAG
CRITERIA/. WILL UPDATE FWF WITH THIS INFORMATION AS THIS SHOULD
CONTINUE THROUGH THE EARLY EVENING HOURS.
DEWPOINTS ALONG CONGESTED CU LINE STARTING TO FALL...SUGGESTING
OUR CONVECTIVE CHANCES ARE WANING...OUTSIDE OF ELEVATED CELLS
TAKING OFF OVER NORTHERN LAKE MICHIGAN...BUT LIKELY TO COME ASHORE
WEST OF CHIP AND MACK.
UPDATE ISSUED AT 100 PM EDT THU MAY 2 2013
CHANGES THIS HOUR: WILL CONTINUE TO EDGE THUNDERSTORM CHANCES WEST
GIVEN CURRENT SURFACE DEWPOINT ANALYSIS AS WELL AS EARLY AFTERNOON
VISIBLE SATELLITE IMAGERY SHOWING BEST CONGESTED CU IN THE HIGH
TERRAIN WEST AND SOUTH OF CADILLAC. COULD CERTAINLY SEE SOME
THUNDER IF CONVECTION CAN BREAK THE 50 J/KG CAPPING THAT REMAINS.
TEMPS A CHALLENGE WITH CAD-HTL-GOV LIKELY TO HIT 80...WITH
IMPRESSIVE DROP JUST TO THE NORTHWEST ACROSS THE SURFACE BOUNDARY.
REMAINDER OF FORECAST IN GOOD SHAPE.
UPDATE ISSUED AT 1018 AM EDT THU MAY 2 2013
CHANGES THIS HOUR: HAVE LOWERED HIGHS JUST A TAD AND DELAYED
SHOWER POTENTIAL TO PRIMARILY 18Z AND BEYOND. OTHERWISE...MINOR
CHANGES TO SKY TO ACCOUNT FOR STRATUS NEAR WHITEFISH POINT.
COOL FRONT SITS OVER THE CWA ATTM WITH 12Z APX RAOB SHOWING VERY
IMPRESSIVE...ALBEIT VERY SHALLOW SURFACE BASED INVERSION WITH T9
AT 19C AND +13C AT H8. BOUNDARY IS LIKELY TO MIX NORTH AND WEST
GIVEN AMPLE SURFACE BASED HEATING OVER NORTHERN LOWER HEADING INTO
EARLY AFTERNOON. SOME CAVEATS TO THIS...HOWEVER...INCLUDE
DEVELOPING MID CLOUDS FROM CAD TO CVX UNDER ISENTROPIC ASCENT AT
THIS LEVEL WHICH MAY HELP REINFORCE THE BOUNDARY IF IT CAN HOLD
TOGETHER. EXPECT THAT IT WILL NOT /OR MORE LIKELY THAT IT WILL
LIFT NORTH WITH TIME/...ALLOWING BOUNDARY TO PUSH TOWARDS THE
COAST OF NW LOWER. THIS SHOULD ALLOW TEMPS TO WORK TOWARDS
PREVIOUSLY FORECASTED HIGHS. CERTAINLY SOME TEMPERATURE BUST
POTENTIAL IN THE VICINITY OF WHERE THIS FRONT MIXES TO THIS
AFTERNOON /TVC-ACB-PLN/.
EARLY MORNING RAP SOUNDINGS HAVE A MUCH BETTER HANDLE ON MOISTURE
OVER ARRIVING AIRMASS FROM SOUTHEAST LOWER THAN THE NAM /12Z DTX
RAOB SHOWS 0C DEWPOINT AT H8...WITH 6C FROM THE NAM/. THE RESULT
OF THIS IS AN AFTERNOON CHARACTERIZED BY MORE MID 40S DEWPOINTS
THAN LOW 50S...REDUCING CONVECTIVE POTENTIAL. WILL THUS DELAY
POPS...BUT NOT PULL THEM AT THIS POINT...BUT AWAIT 12Z GUIDANCE
AND LATE MORNING OBSERVATIONAL TRENDS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 421 AM EDT THU MAY 2 2013
EARLY MORNING SURFACE ANALYSIS SHOWS A COLD/STATIONARY FRONT
EXTENDING FROM NORTHERN QUEBEC...SOUTHWEST ACROSS CENTRAL LOWER
MICHIGAN AND DOWN INTO NORTHWEST ILLINOIS/CENTRAL MISSOURI AND ON
INTO THE SOUTHERN PLAINS. THIS FRONT WAS ASSOCIATED WITH AN UPPER
LEVEL TROUGH ENCOMPASSING THE NATION`S MIDSECTION...AND ITS EASTWARD
PROGRESS WAS BEING IMPEDED BY A NARROW BUT HIGH AMPLITUDE BLOCKING
RIDGE OVER THE EASTERN THIRD OF THE NATION AND SUBSEQUENT TROUGHING
OVER THE WESTERN ATLANTIC. A 30-40 DEGREE TEMPERATURE CONTRAST
EXISTS ACROSS THE FRONT...WITH AN ELONGATED BAND OF POST-FRONTAL
RAIN AND SNOW FROM THE CENTRAL/SOUTHERN PLAINS NORTHWARD INTO THE
UPPER MISSISSIPPI VALLEY. CLOSER TO HOME...SCATTERED CONVECTION
DEVELOPED EARLIER ACROSS EASTERN UPPER MICHIGAN/NORTHERN LAKE
MICHIGAN...THE TAIL END OF A BAND OF SCATTERED SHOWERS AND
THUNDERSTORMS EXTENDING INTO NORTHEAST ONTARIO. OTHERWISE SKIES ARE
CLEAR/PARTLY CLOUDY ACROSS NORTHERN LOWER.
STURDY RIDGE TO THE EAST WILL KEEP THINGS IN A HOLDING PATTERN
TODAY...STATIONARY FRONT WILL LIKELY WAVER A BIT DUE TO MIXING AND
LAKE BREEZE EFFECTS...BUT IS GOING TO ESSENTIALLY BISECT LOWER
MICHIGAN FROM NORTH TO SOUTH THROUGH THE SHORT TERM PERIOD. THIS
PRODUCES A MYRIAD OF FORECAST ISSUES FOR TODAY AND TONIGHT WITH
REGARD TO PRECIP CHANCES...TEMPERATURES...AND WINDS.
PRECIP ISSUES TODAY ARE PROBABLY GOING TO BE SIMILAR TO THOSE OF
WEDNESDAY...THAT IS WILL THERE BE ENOUGH MOISTURE TO GENERATE
INSTABILITY ALONG THE FRONT. FIRST...EXPECT THE FRONT TO MIX BACK
TO THE WEST...PROBABLY BACK TOWARD GLR-GOV-CAD THOUGH NORTHERN END
OF THE FRONT WILL PROBABLY BE DEFORMED IN AN EAST-WEST DIRECTION AS
LAKE HURON BREEZE RAMPS UP. THERE ARE INDICATIONS IN THE FORECAST
SOUNDINGS...PARTICULARLY THE GFS...OF STRATUS DEVELOPING ON THE COOL
SIDE OF THE FRONT VERY SHORTLY. THERE AREN`T ANY INDICATIONS OF
SUCH AS YET...SO WILL START OUT BY DOWNPLAYING THIS IDEA INITIALLY.
CAN SEE THE POSSIBILITY OF LOW CLOUDS DEVELOPING LATER THIS MORNING
AS THERMAL CONTRAST TIGHTENS...SUCH A SCENARIO IS MORE LIKELY OVER
THE COLD WATERS OF LAKE MICHIGAN AND PERHAPS SPILLING INTO ADJACENT
LAKESHORE AREAS OF NORTHWEST LOWER. SO WITH THE FRONT BACKING
TOWARD NORTHWEST LOWER...WILL PROBABLY TAKE DEW POINTS REMAINING IN
THE LOWER 50S TO GENERATE AROUND 500J/KG MLCAPE. TOOK ALL AFTERNOON
YESTERDAY TO GENERATE ONE SHOWER DURING THE EARLY EVENING...WONDER
IF WE`LL BE FACING THE SAME ISSUE TODAY. CURRENT THINKING IS THAT
IT IS CLOSE ENOUGH TO JUSTIFY CHANCE AFTERNOON POPS ACROSS MUCH OF
INTERIOR NORTHERN LOWER. ANOTHER POSSIBILITY FOR NORTHWEST LOWER IS
THAT UNSTABLE WARM SECTOR PARCELS ARE PULLED UP THE FRONTAL ZONE AND
CONVECT ON THE COOL SIDE OF THE BOUNDARY (ALONG/WEST OF US-131
CORRIDOR). SO SEVERAL POSSIBILITIES HERE. AS FOR TEMPERATURES
TODAY...AGAIN WILL VARY WIDELY DEPENDING ON LOCATION RELATIVE TO THE
FRONT AND LAKE BREEZE ACTIVITY. DON`T SEE WHY TEMPERATURES ON THE
WARM SIDE OF THE BOUNDARY WON`T MAKE ANOTHER RUN AT 80+ TODAY AS
CLOUD COVER SHOULD NOT BE MUCH OF AN ISSUE. RECORD HIGHS ARE A BIT
WARMER THAN YESTERDAY (APN 86/2001...HTL 88/1959...GLR 85/1959)...
AND WILL TAKE SOME TIME TO MIX THROUGH THE FRONTAL INVERSION SO
SHOULD BE A LITTLE SLOWER TEMPERATURE CLIMB THIS MORNING.
FOR TONIGHT...WILL BE DEALING BOTH WITH DEEPER MOISTURE NUDGING INTO
WESTERN PORTIONS OF THE FORECAST AREA AS WELL AS ELEVATED
INSTABILITY AND CONTINUE WARM ADVECTION. MUCH OF THE MOISTURE WILL
BE ACROSS THE WESTERN HALF OF THE FORECAST AREA AND THUS HIGHER
POPS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 421 AM EDT THU MAY 2 2013
SPRING LOOKS LIKE IT`S HERE TO STAY FOR THE FORESEEABLE FUTURE...
WITH ACTUALLY VERY FEW FORECAST ISSUES NOTED THROUGH THE WEEKEND AND
MAJORITY OF NEXT WORK WEEK. OVERALL UPPER PATTERN IS PROGGED BY ALL
AVAILABLE MEDIUM RANGE GUIDANCE TO REMAIN HEAVILY BLOCKED UP AS
CLOSED LOW DEVELOPMENT TAKES PLACE OVER THE MID MISSISSIPPI
VALLEY...WHILE ANOTHER CLOSED LOW MEANDER OVER THE WESTERN
ATLANTIC...EFFECTIVELY PINNING A RATHER EXPANSIVE OMEGA-TYPE RIDGE
IN PLACE FROM FLORIDA RIGHT ON UP THROUGH THE GREAT LAKES AND MUCH
OF EASTERN CANADA. THAT RIDGE SHOULD INCREASINGLY BECOME CUT OFF
OVER THE NORTHERN TIER FOR THE FIRST PART OF NEXT WEEK...AS THE
CLOSED LOW WANDERS RATHER AIMLESSLY SOMEWHERE TO OUR SOUTH (EXACT
POSITION STILL TO BE DETERMINED). AS THAT OCCURS...PREVAILING SOUTH
TO SOUTHEASTERLY LOW LEVEL FLOW WILL CONTINUE TO TRANSPORT SOME
RATHER MILD AIR NORTHWARD AS A PERSISTENT THERMAL RIDGE FEATURE
HOLDS INTACT ACROSS THE GREAT LAKES...FAVORING SOME MORE MUCH NEEDED
(AND LET`S FACE IT...MUCH DESERVED) WARM SPRINGTIME WEATHER FOR THE
NORTH WOODS.
LOOKING AT SOME SPECIFICS...STALLED FRONTAL BOUNDARY/INVERTED
TROUGH AXIS REMAINS PROGGED TO RESIDE ACROSS THE AREA THROUGH
FRIDAY...EFFECTIVELY SPLITTING THE STATE IN HALF. GIVEN YESTERDAY`S
HISTORY WITH THIS BOUNDARY COUPLED WITH AN INCREASINGLY DRIER
BOUNDARY LAYER LIKELY TO BE SHUNTED INTO THE REGION ON SLOWLY
BACKING SOUTHEAST FLOW REGIME...HAVE SOME DIFFICULTY BELIEVING WE
WILL BE ABLE TO MUSTER MUCH IN THE WAY OF ANY AFTERNOON CONVECTION.
WITH THAT SAID...THE CHANCE IS NOT COMPLETELY ZERO WITH A LIGHT
WIND/LAKE BREEZE REGIME FAVORING ENHANCED CONVERGENCE INTO THE
SLUGGISH SYNOPTIC BOUNDARY...AND AT LEAST DECENT HEATING ACROSS
NORTHEAST LOWER AND THE HIGHER TERRAIN.
THEREAFTER...JUST CANNOT JUSTIFY HAVING ANY POPS IN THE FORECAST
BEYOND FRIDAY EVENING...AS THE ENTIRE PATTERN SLOWLY RETROGRADES AND
THE BEST MOISTURE AXIS SLIPS WELL TO OUR WEST...ALL WHILE AN
INCREASINGLY DRY BOUNDARY LAYER MAKES AN APPEARANCE THROUGH THE
WEEKEND. LOOKING INTO NEXT WEEK...DEEPER MOISTURE AXIS SHOULD REMAIN
WELL TO OUR SOUTH AS THE UPPER LOW PINWHEELS THROUGH THE TENNESSEE
VALLEY (OR SOMEWHERE NEAR THERE)...WITH DRY EASTERLY FLOW PREVAILING
UP THIS WAY AND SUBSIDENCE ON THE NORTHERN FRINGE OF CLOSED LOW
FEATURE FAVORING LOTS OF SUNSHINE. HIGHS SHOULD RESPOND NICELY INTO
THE 60S TO MIDDLE 70S EACH AFTERNOON...COOLER NEAR THE LAKESHORES OF
COURSE WHERE LAKE BREEZE DEVELOPMENT IS LIKELY EACH DAY GIVEN A VERY
WEAK GRADIENT IN PLACE. OVERNIGHT LOWS ARE A BIT MORE TRICKY IN THIS
LIGHT GRADIENT SETUP...AS DAILY MIXING OF DEW POINTS INTO THE 40S
AND MAYBE 30S AND CLEAR SKIES SHOULD EASILY ALLOW READINGS TO DIP
QUICKLY AFTER SUNSET. SIMPLY PUT...THE WEATHER THROUGH NEXT WEEK
LOOKS DOWNRIGHT SPECTACULAR FOR ALL OF NORTHERN MICHIGAN...WITH WARM
SUNNY DAYS AND COOL COMFORTABLE NIGHTS. ENJOY!
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 136 PM EDT THU MAY 2 2013
SUMMARY: A STALLED FRONTAL SYSTEM WILL REMAIN JUST WEST OF
NORTHERN MICHIGAN THROUGH THE UPCOMING TAF PERIOD. THIS WILL BRING
THE CHANCE FOR SCATTERED SHOWERS AND EMBEDDED THUNDERSTORMS TO
MBL-TVC-PLN THROUGH 18Z FRIDAY.
RESTRICTIONS:VFR CONDITIONS ONGOING AND EXPECTED TO CONTINUE INTO
THIS EVENING. SOME SHRA/TSRA DEVELOPMENT POSSIBLE FROM TVC SOUTH
TO CAD THIS EVENING. WILL INCLUDE TEMPO MENTION AT MBL-TVC...BUT
REFRAIN FROM INCLUDING THUNDER AT THIS POINT GIVEN LACKLUSTER
INSTABILITY AND LOW CONFIDENCE IN THUNDER OCCURRENCE. OVERNIGHT...
PRIMARY CONCERN IS FOR THE DEVELOPMENT OF STRATUS OVER NORTHWEST
LOWER MICHIGAN. WILL INCLUDE THIS AFTER MIDNIGHT AT MBL/TVC...BUT
CONFIDENCE IS BELOW AVERAGE ON OCCURRENCE. ANY STRATUS SHOULD
QUICKLY MIX OUT FRIDAY MORNING WITH VFR CONDITIONS RESUMING THOUGH
THE END OF THE FORECAST PERIOD.
WINDS: CURRENTLY DOMINATED BY LOCAL LAKE BREEZES 10G15KTS THROUGH
LATE AFTERNOON WILL BECOME LIGHT/VARIABLE TONIGHT BEFORE MORE
NORTHEASTERLY WINDS AROUND 10KTS TAKE OVER FOR THE DAY ON FRIDAY
/EXCEPT AT APN WHERE A SOUTHEAST DIRECTION WILL CONTINUE/.
&&
.MARINE...
ISSUED AT 421 AM EDT THU MAY 2 2013
STATIONARY FRONT BISECTING LOWER MICHIGAN FROM NORTH TO SOUTH WILL
PRODUCE VERY DIFFERENT WIND CONDITIONS BETWEEN WHITEFISH BAY/LAKE
MICHIGAN AND LAKE HURON NEARSHORE ZONES...EVEN ON LAKE HURON
CONDITIONS WILL VARY QUITE A BIT. WESTERN ZONES WILL BE DEALING
WITH A STRONGER NORTHERLY GRADIENT ON THE COOLER SIDE OF THE
BOUNDARY...MAY PUSH SMALL CRAFT CONDITIONS WITHIN NORTHWEST LOWER
NEARSHORE ZONES. ON LAKE HURON...WINDS WILL VARY FROM A NORTHERLY
COMPONENT NORTH OF THUNDER BAY...AND A SOUTHERLY COMPONENT SOUTH
THOUGH BOTH AREAS WILL BE IMPACTED LOCALLY BY LAKE BREEZE COMPONENTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LMZ323-
344>346.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...DL
SHORT TERM...JPB
LONG TERM...DL
AVIATION...ARNOTT
MARINE...JPB
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
149 PM EDT THU MAY 2 2013
.SYNOPSIS...
ISSUED AT 421 AM EDT THU MAY 2 2013
A STRONG LOW PRESSURE SYSTEM WILL TAKE SHAPE ACROSS THE CENTRAL
PLAINS AND MID MISSISSIPPI VALLEY THROUGH THE WEEKEND...AS UPPER
LEVEL HIGH PRESSURE REMAINS PARKED ACROSS THE GREAT LAKES AND
NORTHEAST STATES. THIS WEATHER PATTERN WILL YIELD CONTINUED MILD
TEMPERATURES RIGHT ON THROUGH THE WEEKEND...WITH JUST A FEW SMALL
CHANCES FOR MAINLY AFTERNOON RAIN SHOWERS. DRY BUT CONTINUED WARM
WEATHER IS EXPECTED FOR MUCH OF NEXT WEEK...AS HIGH PRESSURE REMAINS
IN CONTROL ACROSS THE GREAT LAKES.
&&
.UPDATE...
ISSUED AT 100 PM EDT THU MAY 2 2013
CHANGES THIS HOUR: WILL CONTINUE TO EDGE THUNDERSTORM CHANCES WEST
GIVEN CURRENT SURFACE DEWPOINT ANALYSIS AS WELL AS EARLY AFTERNOON
VISIBLE SATELLITE IMAGERY SHOWING BEST CONGESTED CU IN THE HIGH
TERRAIN WEST AND SOUTH OF CADILLAC. COULD CERTAINLY SEE SOME
THUNDER IF CONVECTION CAN BREAK THE 50 J/KG CAPPING THAT REMAINS.
TEMPS A CHALLENGE WITH CAD-HTL-GOV LIKELY TO HIT 80...WITH
IMPRESSIVE DROP JUST TO THE NORTHWEST ACROSS THE SURFACE BOUNDARY.
REMAINDER OF FORECAST IN GOOD SHAPE.
UPDATE ISSUED AT 1018 AM EDT THU MAY 2 2013
CHANGES THIS HOUR: HAVE LOWERED HIGHS JUST A TAD AND DELAYED
SHOWER POTENTIAL TO PRIMARILY 18Z AND BEYOND. OTHERWISE...MINOR
CHANGES TO SKY TO ACCOUNT FOR STRATUS NEAR WHITEFISH POINT.
COOL FRONT SITS OVER THE CWA ATTM WITH 12Z APX RAOB SHOWING VERY
IMPRESSIVE...ALBEIT VERY SHALLOW SURFACE BASED INVERSION WITH T9
AT 19C AND +13C AT H8. BOUNDARY IS LIKELY TO MIX NORTH AND WEST
GIVEN AMPLE SURFACE BASED HEATING OVER NORTHERN LOWER HEADING INTO
EARLY AFTERNOON. SOME CAVEATS TO THIS...HOWEVER...INCLUDE
DEVELOPING MID CLOUDS FROM CAD TO CVX UNDER ISENTROPIC ASCENT AT
THIS LEVEL WHICH MAY HELP REINFORCE THE BOUNDARY IF IT CAN HOLD
TOGETHER. EXPECT THAT IT WILL NOT /OR MORE LIKELY THAT IT WILL
LIFT NORTH WITH TIME/...ALLOWING BOUNDARY TO PUSH TOWARDS THE
COAST OF NW LOWER. THIS SHOULD ALLOW TEMPS TO WORK TOWARDS
PREVIOUSLY FORECASTED HIGHS. CERTAINLY SOME TEMPERATURE BUST
POTENTIAL IN THE VICINITY OF WHERE THIS FRONT MIXES TO THIS
AFTERNOON /TVC-ACB-PLN/.
EARLY MORNING RAP SOUNDINGS HAVE A MUCH BETTER HANDLE ON MOISTURE
OVER ARRIVING AIRMASS FROM SOUTHEAST LOWER THAN THE NAM /12Z DTX
RAOB SHOWS 0C DEWPOINT AT H8...WITH 6C FROM THE NAM/. THE RESULT
OF THIS IS AN AFTERNOON CHARACTERIZED BY MORE MID 40S DEWPOINTS
THAN LOW 50S...REDUCING CONVECTIVE POTENTIAL. WILL THUS DELAY
POPS...BUT NOT PULL THEM AT THIS POINT...BUT AWAIT 12Z GUIDANCE
AND LATE MORNING OBSERVATIONAL TRENDS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 421 AM EDT THU MAY 2 2013
EARLY MORNING SURFACE ANALYSIS SHOWS A COLD/STATIONARY FRONT
EXTENDING FROM NORTHERN QUEBEC...SOUTHWEST ACROSS CENTRAL LOWER
MICHIGAN AND DOWN INTO NORTHWEST ILLINOIS/CENTRAL MISSOURI AND ON
INTO THE SOUTHERN PLAINS. THIS FRONT WAS ASSOCIATED WITH AN UPPER
LEVEL TROUGH ENCOMPASSING THE NATION`S MIDSECTION...AND ITS EASTWARD
PROGRESS WAS BEING IMPEDED BY A NARROW BUT HIGH AMPLITUDE BLOCKING
RIDGE OVER THE EASTERN THIRD OF THE NATION AND SUBSEQUENT TROUGHING
OVER THE WESTERN ATLANTIC. A 30-40 DEGREE TEMPERATURE CONTRAST
EXISTS ACROSS THE FRONT...WITH AN ELONGATED BAND OF POST-FRONTAL
RAIN AND SNOW FROM THE CENTRAL/SOUTHERN PLAINS NORTHWARD INTO THE
UPPER MISSISSIPPI VALLEY. CLOSER TO HOME...SCATTERED CONVECTION
DEVELOPED EARLIER ACROSS EASTERN UPPER MICHIGAN/NORTHERN LAKE
MICHIGAN...THE TAIL END OF A BAND OF SCATTERED SHOWERS AND
THUNDERSTORMS EXTENDING INTO NORTHEAST ONTARIO. OTHERWISE SKIES ARE
CLEAR/PARTLY CLOUDY ACROSS NORTHERN LOWER.
STURDY RIDGE TO THE EAST WILL KEEP THINGS IN A HOLDING PATTERN
TODAY...STATIONARY FRONT WILL LIKELY WAVER A BIT DUE TO MIXING AND
LAKE BREEZE EFFECTS...BUT IS GOING TO ESSENTIALLY BISECT LOWER
MICHIGAN FROM NORTH TO SOUTH THROUGH THE SHORT TERM PERIOD. THIS
PRODUCES A MYRIAD OF FORECAST ISSUES FOR TODAY AND TONIGHT WITH
REGARD TO PRECIP CHANCES...TEMPERATURES...AND WINDS.
PRECIP ISSUES TODAY ARE PROBABLY GOING TO BE SIMILAR TO THOSE OF
WEDNESDAY...THAT IS WILL THERE BE ENOUGH MOISTURE TO GENERATE
INSTABILITY ALONG THE FRONT. FIRST...EXPECT THE FRONT TO MIX BACK
TO THE WEST...PROBABLY BACK TOWARD GLR-GOV-CAD THOUGH NORTHERN END
OF THE FRONT WILL PROBABLY BE DEFORMED IN AN EAST-WEST DIRECTION AS
LAKE HURON BREEZE RAMPS UP. THERE ARE INDICATIONS IN THE FORECAST
SOUNDINGS...PARTICULARLY THE GFS...OF STRATUS DEVELOPING ON THE COOL
SIDE OF THE FRONT VERY SHORTLY. THERE AREN`T ANY INDICATIONS OF
SUCH AS YET...SO WILL START OUT BY DOWNPLAYING THIS IDEA INITIALLY.
CAN SEE THE POSSIBILITY OF LOW CLOUDS DEVELOPING LATER THIS MORNING
AS THERMAL CONTRAST TIGHTENS...SUCH A SCENARIO IS MORE LIKELY OVER
THE COLD WATERS OF LAKE MICHIGAN AND PERHAPS SPILLING INTO ADJACENT
LAKESHORE AREAS OF NORTHWEST LOWER. SO WITH THE FRONT BACKING
TOWARD NORTHWEST LOWER...WILL PROBABLY TAKE DEW POINTS REMAINING IN
THE LOWER 50S TO GENERATE AROUND 500J/KG MLCAPE. TOOK ALL AFTERNOON
YESTERDAY TO GENERATE ONE SHOWER DURING THE EARLY EVENING...WONDER
IF WE`LL BE FACING THE SAME ISSUE TODAY. CURRENT THINKING IS THAT
IT IS CLOSE ENOUGH TO JUSTIFY CHANCE AFTERNOON POPS ACROSS MUCH OF
INTERIOR NORTHERN LOWER. ANOTHER POSSIBILITY FOR NORTHWEST LOWER IS
THAT UNSTABLE WARM SECTOR PARCELS ARE PULLED UP THE FRONTAL ZONE AND
CONVECT ON THE COOL SIDE OF THE BOUNDARY (ALONG/WEST OF US-131
CORRIDOR). SO SEVERAL POSSIBILITIES HERE. AS FOR TEMPERATURES
TODAY...AGAIN WILL VARY WIDELY DEPENDING ON LOCATION RELATIVE TO THE
FRONT AND LAKE BREEZE ACTIVITY. DON`T SEE WHY TEMPERATURES ON THE
WARM SIDE OF THE BOUNDARY WON`T MAKE ANOTHER RUN AT 80+ TODAY AS
CLOUD COVER SHOULD NOT BE MUCH OF AN ISSUE. RECORD HIGHS ARE A BIT
WARMER THAN YESTERDAY (APN 86/2001...HTL 88/1959...GLR 85/1959)...
AND WILL TAKE SOME TIME TO MIX THROUGH THE FRONTAL INVERSION SO
SHOULD BE A LITTLE SLOWER TEMPERATURE CLIMB THIS MORNING.
FOR TONIGHT...WILL BE DEALING BOTH WITH DEEPER MOISTURE NUDGING INTO
WESTERN PORTIONS OF THE FORECAST AREA AS WELL AS ELEVATED
INSTABILITY AND CONTINUE WARM ADVECTION. MUCH OF THE MOISTURE WILL
BE ACROSS THE WESTERN HALF OF THE FORECAST AREA AND THUS HIGHER
POPS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 421 AM EDT THU MAY 2 2013
SPRING LOOKS LIKE IT`S HERE TO STAY FOR THE FORESEEABLE FUTURE...
WITH ACTUALLY VERY FEW FORECAST ISSUES NOTED THROUGH THE WEEKEND AND
MAJORITY OF NEXT WORK WEEK. OVERALL UPPER PATTERN IS PROGGED BY ALL
AVAILABLE MEDIUM RANGE GUIDANCE TO REMAIN HEAVILY BLOCKED UP AS
CLOSED LOW DEVELOPMENT TAKES PLACE OVER THE MID MISSISSIPPI
VALLEY...WHILE ANOTHER CLOSED LOW MEANDER OVER THE WESTERN
ATLANTIC...EFFECTIVELY PINNING A RATHER EXPANSIVE OMEGA-TYPE RIDGE
IN PLACE FROM FLORIDA RIGHT ON UP THROUGH THE GREAT LAKES AND MUCH
OF EASTERN CANADA. THAT RIDGE SHOULD INCREASINGLY BECOME CUT OFF
OVER THE NORTHERN TIER FOR THE FIRST PART OF NEXT WEEK...AS THE
CLOSED LOW WANDERS RATHER AIMLESSLY SOMEWHERE TO OUR SOUTH (EXACT
POSITION STILL TO BE DETERMINED). AS THAT OCCURS...PREVAILING SOUTH
TO SOUTHEASTERLY LOW LEVEL FLOW WILL CONTINUE TO TRANSPORT SOME
RATHER MILD AIR NORTHWARD AS A PERSISTENT THERMAL RIDGE FEATURE
HOLDS INTACT ACROSS THE GREAT LAKES...FAVORING SOME MORE MUCH NEEDED
(AND LET`S FACE IT...MUCH DESERVED) WARM SPRINGTIME WEATHER FOR THE
NORTH WOODS.
LOOKING AT SOME SPECIFICS...STALLED FRONTAL BOUNDARY/INVERTED
TROUGH AXIS REMAINS PROGGED TO RESIDE ACROSS THE AREA THROUGH
FRIDAY...EFFECTIVELY SPLITTING THE STATE IN HALF. GIVEN YESTERDAY`S
HISTORY WITH THIS BOUNDARY COUPLED WITH AN INCREASINGLY DRIER
BOUNDARY LAYER LIKELY TO BE SHUNTED INTO THE REGION ON SLOWLY
BACKING SOUTHEAST FLOW REGIME...HAVE SOME DIFFICULTY BELIEVING WE
WILL BE ABLE TO MUSTER MUCH IN THE WAY OF ANY AFTERNOON CONVECTION.
WITH THAT SAID...THE CHANCE IS NOT COMPLETELY ZERO WITH A LIGHT
WIND/LAKE BREEZE REGIME FAVORING ENHANCED CONVERGENCE INTO THE
SLUGGISH SYNOPTIC BOUNDARY...AND AT LEAST DECENT HEATING ACROSS
NORTHEAST LOWER AND THE HIGHER TERRAIN.
THEREAFTER...JUST CANNOT JUSTIFY HAVING ANY POPS IN THE FORECAST
BEYOND FRIDAY EVENING...AS THE ENTIRE PATTERN SLOWLY RETROGRADES AND
THE BEST MOISTURE AXIS SLIPS WELL TO OUR WEST...ALL WHILE AN
INCREASINGLY DRY BOUNDARY LAYER MAKES AN APPEARANCE THROUGH THE
WEEKEND. LOOKING INTO NEXT WEEK...DEEPER MOISTURE AXIS SHOULD REMAIN
WELL TO OUR SOUTH AS THE UPPER LOW PINWHEELS THROUGH THE TENNESSEE
VALLEY (OR SOMEWHERE NEAR THERE)...WITH DRY EASTERLY FLOW PREVAILING
UP THIS WAY AND SUBSIDENCE ON THE NORTHERN FRINGE OF CLOSED LOW
FEATURE FAVORING LOTS OF SUNSHINE. HIGHS SHOULD RESPOND NICELY INTO
THE 60S TO MIDDLE 70S EACH AFTERNOON...COOLER NEAR THE LAKESHORES OF
COURSE WHERE LAKE BREEZE DEVELOPMENT IS LIKELY EACH DAY GIVEN A VERY
WEAK GRADIENT IN PLACE. OVERNIGHT LOWS ARE A BIT MORE TRICKY IN THIS
LIGHT GRADIENT SETUP...AS DAILY MIXING OF DEW POINTS INTO THE 40S
AND MAYBE 30S AND CLEAR SKIES SHOULD EASILY ALLOW READINGS TO DIP
QUICKLY AFTER SUNSET. SIMPLY PUT...THE WEATHER THROUGH NEXT WEEK
LOOKS DOWNRIGHT SPECTACULAR FOR ALL OF NORTHERN MICHIGAN...WITH WARM
SUNNY DAYS AND COOL COMFORTABLE NIGHTS. ENJOY!
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 136 PM EDT THU MAY 2 2013
SUMMARY: A STALLED FRONTAL SYSTEM WILL REMAIN JUST WEST OF
NORTHERN MICHIGAN THROUGH THE UPCOMING TAF PERIOD. THIS WILL BRING
THE CHANCE FOR SCATTERED SHOWERS AND EMBEDDED THUNDERSTORMS TO
MBL-TVC-PLN THROUGH 18Z FRIDAY.
RESTRICTIONS:VFR CONDITIONS ONGOING AND EXPECTED TO CONTINUE INTO
THIS EVENING. SOME SHRA/TSRA DEVELOPMENT POSSIBLE FROM TVC SOUTH
TO CAD THIS EVENING. WILL INCLUDE TEMPO MENTION AT MBL-TVC...BUT
REFRAIN FROM INCLUDING THUNDER AT THIS POINT GIVEN LACKLUSTER
INSTABILITY AND LOW CONFIDENCE IN THUNDER OCCURRENCE. OVERNIGHT...
PRIMARY CONCERN IS FOR THE DEVELOPMENT OF STRATUS OVER NORTHWEST
LOWER MICHIGAN. WILL INCLUDE THIS AFTER MIDNIGHT AT MBL/TVC...BUT
CONFIDENCE IS BELOW AVERAGE ON OCCURRENCE. ANY STRATUS SHOULD
QUICKLY MIX OUT FRIDAY MORNING WITH VFR CONDITIONS RESUMING THOUGH
THE END OF THE FORECAST PERIOD.
WINDS: CURRENTLY DOMINATED BY LOCAL LAKE BREEZES 10G15KTS THROUGH
LATE AFTERNOON WILL BECOME LIGHT/VARIABLE TONIGHT BEFORE MORE
NORTHEASTERLY WINDS AROUND 10KTS TAKE OVER FOR THE DAY ON FRIDAY
/EXCEPT AT APN WHERE A SOUTHEAST DIRECTION WILL CONTINUE/.
&&
.MARINE...
ISSUED AT 421 AM EDT THU MAY 2 2013
STATIONARY FRONT BISECTING LOWER MICHIGAN FROM NORTH TO SOUTH WILL
PRODUCE VERY DIFFERENT WIND CONDITIONS BETWEEN WHITEFISH BAY/LAKE
MICHIGAN AND LAKE HURON NEARSHORE ZONES...EVEN ON LAKE HURON
CONDITIONS WILL VARY QUITE A BIT. WESTERN ZONES WILL BE DEALING
WITH A STRONGER NORTHERLY GRADIENT ON THE COOLER SIDE OF THE
BOUNDARY...MAY PUSH SMALL CRAFT CONDITIONS WITHIN NORTHWEST LOWER
NEARSHORE ZONES. ON LAKE HURON...WINDS WILL VARY FROM A NORTHERLY
COMPONENT NORTH OF THUNDER BAY...AND A SOUTHERLY COMPONENT SOUTH
THOUGH BOTH AREAS WILL BE IMPACTED LOCALLY BY LAKE BREEZE COMPONENTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LMZ323-
344>346.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...DL
SHORT TERM...JPB
LONG TERM...DL
AVIATION...ARNOTT
MARINE...JPB
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
101 PM EDT THU MAY 2 2013
.SYNOPSIS...
ISSUED AT 421 AM EDT THU MAY 2 2013
A STRONG LOW PRESSURE SYSTEM WILL TAKE SHAPE ACROSS THE CENTRAL
PLAINS AND MID MISSISSIPPI VALLEY THROUGH THE WEEKEND...AS UPPER
LEVEL HIGH PRESSURE REMAINS PARKED ACROSS THE GREAT LAKES AND
NORTHEAST STATES. THIS WEATHER PATTERN WILL YIELD CONTINUED MILD
TEMPERATURES RIGHT ON THROUGH THE WEEKEND...WITH JUST A FEW SMALL
CHANCES FOR MAINLY AFTERNOON RAIN SHOWERS. DRY BUT CONTINUED WARM
WEATHER IS EXPECTED FOR MUCH OF NEXT WEEK...AS HIGH PRESSURE REMAINS
IN CONTROL ACROSS THE GREAT LAKES.
&&
.UPDATE...
ISSUED AT 100 PM EDT THU MAY 2 2013
CHANGES THIS HOUR: WILL CONTINUE TO EDGE THUNDERSTORM CHANCES WEST
GIVEN CURRENT SURFACE DEWPOINT ANALYSIS AS WELL AS EARLY AFTERNOON
VISIBLE SATELLITE IMAGERY SHOWING BEST CONGESTED CU IN THE HIGH
TERRAIN WEST AND SOUTH OF CADILLAC. COULD CERTAINLY SEE SOME
THUNDER IF CONVECTION CAN BREAK THE 50 J/KG CAPPING THAT REMAINS.
TEMPS A CHALLENGE WITH CAD-HTL-GOV LIKELY TO HIT 80...WITH
IMPRESSIVE DROP JUST TO THE NORTHWEST ACROSS THE SURFACE BOUNDARY.
REMAINDER OF FORECAST IN GOOD SHAPE.
UPDATE ISSUED AT 1018 AM EDT THU MAY 2 2013
CHANGES THIS HOUR: HAVE LOWERED HIGHS JUST A TAD AND DELAYED
SHOWER POTENTIAL TO PRIMARILY 18Z AND BEYOND. OTHERWISE...MINOR
CHANGES TO SKY TO ACCOUNT FOR STRATUS NEAR WHITEFISH POINT.
COOL FRONT SITS OVER THE CWA ATTM WITH 12Z APX RAOB SHOWING VERY
IMPRESSIVE...ALBEIT VERY SHALLOW SURFACE BASED INVERSION WITH T9
AT 19C AND +13C AT H8. BOUNDARY IS LIKELY TO MIX NORTH AND WEST
GIVEN AMPLE SURFACE BASED HEATING OVER NORTHERN LOWER HEADING INTO
EARLY AFTERNOON. SOME CAVEATS TO THIS...HOWEVER...INCLUDE
DEVELOPING MID CLOUDS FROM CAD TO CVX UNDER ISENTROPIC ASCENT AT
THIS LEVEL WHICH MAY HELP REINFORCE THE BOUNDARY IF IT CAN HOLD
TOGETHER. EXPECT THAT IT WILL NOT /OR MORE LIKELY THAT IT WILL
LIFT NORTH WITH TIME/...ALLOWING BOUNDARY TO PUSH TOWARDS THE
COAST OF NW LOWER. THIS SHOULD ALLOW TEMPS TO WORK TOWARDS
PREVIOUSLY FORECASTED HIGHS. CERTAINLY SOME TEMPERATURE BUST
POTENTIAL IN THE VICINITY OF WHERE THIS FRONT MIXES TO THIS
AFTERNOON /TVC-ACB-PLN/.
EARLY MORNING RAP SOUNDINGS HAVE A MUCH BETTER HANDLE ON MOISTURE
OVER ARRIVING AIRMASS FROM SOUTHEAST LOWER THAN THE NAM /12Z DTX
RAOB SHOWS 0C DEWPOINT AT H8...WITH 6C FROM THE NAM/. THE RESULT
OF THIS IS AN AFTERNOON CHARACTERIZED BY MORE MID 40S DEWPOINTS
THAN LOW 50S...REDUCING CONVECTIVE POTENTIAL. WILL THUS DELAY
POPS...BUT NOT PULL THEM AT THIS POINT...BUT AWAIT 12Z GUIDANCE
AND LATE MORNING OBSERVATIONAL TRENDS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 421 AM EDT THU MAY 2 2013
EARLY MORNING SURFACE ANALYSIS SHOWS A COLD/STATIONARY FRONT
EXTENDING FROM NORTHERN QUEBEC...SOUTHWEST ACROSS CENTRAL LOWER
MICHIGAN AND DOWN INTO NORTHWEST ILLINOIS/CENTRAL MISSOURI AND ON
INTO THE SOUTHERN PLAINS. THIS FRONT WAS ASSOCIATED WITH AN UPPER
LEVEL TROUGH ENCOMPASSING THE NATION`S MIDSECTION...AND ITS EASTWARD
PROGRESS WAS BEING IMPEDED BY A NARROW BUT HIGH AMPLITUDE BLOCKING
RIDGE OVER THE EASTERN THIRD OF THE NATION AND SUBSEQUENT TROUGHING
OVER THE WESTERN ATLANTIC. A 30-40 DEGREE TEMPERATURE CONTRAST
EXISTS ACROSS THE FRONT...WITH AN ELONGATED BAND OF POST-FRONTAL
RAIN AND SNOW FROM THE CENTRAL/SOUTHERN PLAINS NORTHWARD INTO THE
UPPER MISSISSIPPI VALLEY. CLOSER TO HOME...SCATTERED CONVECTION
DEVELOPED EARLIER ACROSS EASTERN UPPER MICHIGAN/NORTHERN LAKE
MICHIGAN...THE TAIL END OF A BAND OF SCATTERED SHOWERS AND
THUNDERSTORMS EXTENDING INTO NORTHEAST ONTARIO. OTHERWISE SKIES ARE
CLEAR/PARTLY CLOUDY ACROSS NORTHERN LOWER.
STURDY RIDGE TO THE EAST WILL KEEP THINGS IN A HOLDING PATTERN
TODAY...STATIONARY FRONT WILL LIKELY WAVER A BIT DUE TO MIXING AND
LAKE BREEZE EFFECTS...BUT IS GOING TO ESSENTIALLY BISECT LOWER
MICHIGAN FROM NORTH TO SOUTH THROUGH THE SHORT TERM PERIOD. THIS
PRODUCES A MYRIAD OF FORECAST ISSUES FOR TODAY AND TONIGHT WITH
REGARD TO PRECIP CHANCES...TEMPERATURES...AND WINDS.
PRECIP ISSUES TODAY ARE PROBABLY GOING TO BE SIMILAR TO THOSE OF
WEDNESDAY...THAT IS WILL THERE BE ENOUGH MOISTURE TO GENERATE
INSTABILITY ALONG THE FRONT. FIRST...EXPECT THE FRONT TO MIX BACK
TO THE WEST...PROBABLY BACK TOWARD GLR-GOV-CAD THOUGH NORTHERN END
OF THE FRONT WILL PROBABLY BE DEFORMED IN AN EAST-WEST DIRECTION AS
LAKE HURON BREEZE RAMPS UP. THERE ARE INDICATIONS IN THE FORECAST
SOUNDINGS...PARTICULARLY THE GFS...OF STRATUS DEVELOPING ON THE COOL
SIDE OF THE FRONT VERY SHORTLY. THERE AREN`T ANY INDICATIONS OF
SUCH AS YET...SO WILL START OUT BY DOWNPLAYING THIS IDEA INITIALLY.
CAN SEE THE POSSIBILITY OF LOW CLOUDS DEVELOPING LATER THIS MORNING
AS THERMAL CONTRAST TIGHTENS...SUCH A SCENARIO IS MORE LIKELY OVER
THE COLD WATERS OF LAKE MICHIGAN AND PERHAPS SPILLING INTO ADJACENT
LAKESHORE AREAS OF NORTHWEST LOWER. SO WITH THE FRONT BACKING
TOWARD NORTHWEST LOWER...WILL PROBABLY TAKE DEW POINTS REMAINING IN
THE LOWER 50S TO GENERATE AROUND 500J/KG MLCAPE. TOOK ALL AFTERNOON
YESTERDAY TO GENERATE ONE SHOWER DURING THE EARLY EVENING...WONDER
IF WE`LL BE FACING THE SAME ISSUE TODAY. CURRENT THINKING IS THAT
IT IS CLOSE ENOUGH TO JUSTIFY CHANCE AFTERNOON POPS ACROSS MUCH OF
INTERIOR NORTHERN LOWER. ANOTHER POSSIBILITY FOR NORTHWEST LOWER IS
THAT UNSTABLE WARM SECTOR PARCELS ARE PULLED UP THE FRONTAL ZONE AND
CONVECT ON THE COOL SIDE OF THE BOUNDARY (ALONG/WEST OF US-131
CORRIDOR). SO SEVERAL POSSIBILITIES HERE. AS FOR TEMPERATURES
TODAY...AGAIN WILL VARY WIDELY DEPENDING ON LOCATION RELATIVE TO THE
FRONT AND LAKE BREEZE ACTIVITY. DON`T SEE WHY TEMPERATURES ON THE
WARM SIDE OF THE BOUNDARY WON`T MAKE ANOTHER RUN AT 80+ TODAY AS
CLOUD COVER SHOULD NOT BE MUCH OF AN ISSUE. RECORD HIGHS ARE A BIT
WARMER THAN YESTERDAY (APN 86/2001...HTL 88/1959...GLR 85/1959)...
AND WILL TAKE SOME TIME TO MIX THROUGH THE FRONTAL INVERSION SO
SHOULD BE A LITTLE SLOWER TEMPERATURE CLIMB THIS MORNING.
FOR TONIGHT...WILL BE DEALING BOTH WITH DEEPER MOISTURE NUDGING INTO
WESTERN PORTIONS OF THE FORECAST AREA AS WELL AS ELEVATED
INSTABILITY AND CONTINUE WARM ADVECTION. MUCH OF THE MOISTURE WILL
BE ACROSS THE WESTERN HALF OF THE FORECAST AREA AND THUS HIGHER
POPS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 421 AM EDT THU MAY 2 2013
SPRING LOOKS LIKE IT`S HERE TO STAY FOR THE FORESEEABLE FUTURE...
WITH ACTUALLY VERY FEW FORECAST ISSUES NOTED THROUGH THE WEEKEND AND
MAJORITY OF NEXT WORK WEEK. OVERALL UPPER PATTERN IS PROGGED BY ALL
AVAILABLE MEDIUM RANGE GUIDANCE TO REMAIN HEAVILY BLOCKED UP AS
CLOSED LOW DEVELOPMENT TAKES PLACE OVER THE MID MISSISSIPPI
VALLEY...WHILE ANOTHER CLOSED LOW MEANDER OVER THE WESTERN
ATLANTIC...EFFECTIVELY PINNING A RATHER EXPANSIVE OMEGA-TYPE RIDGE
IN PLACE FROM FLORIDA RIGHT ON UP THROUGH THE GREAT LAKES AND MUCH
OF EASTERN CANADA. THAT RIDGE SHOULD INCREASINGLY BECOME CUT OFF
OVER THE NORTHERN TIER FOR THE FIRST PART OF NEXT WEEK...AS THE
CLOSED LOW WANDERS RATHER AIMLESSLY SOMEWHERE TO OUR SOUTH (EXACT
POSITION STILL TO BE DETERMINED). AS THAT OCCURS...PREVAILING SOUTH
TO SOUTHEASTERLY LOW LEVEL FLOW WILL CONTINUE TO TRANSPORT SOME
RATHER MILD AIR NORTHWARD AS A PERSISTENT THERMAL RIDGE FEATURE
HOLDS INTACT ACROSS THE GREAT LAKES...FAVORING SOME MORE MUCH NEEDED
(AND LET`S FACE IT...MUCH DESERVED) WARM SPRINGTIME WEATHER FOR THE
NORTH WOODS.
LOOKING AT SOME SPECIFICS...STALLED FRONTAL BOUNDARY/INVERTED
TROUGH AXIS REMAINS PROGGED TO RESIDE ACROSS THE AREA THROUGH
FRIDAY...EFFECTIVELY SPLITTING THE STATE IN HALF. GIVEN YESTERDAY`S
HISTORY WITH THIS BOUNDARY COUPLED WITH AN INCREASINGLY DRIER
BOUNDARY LAYER LIKELY TO BE SHUNTED INTO THE REGION ON SLOWLY
BACKING SOUTHEAST FLOW REGIME...HAVE SOME DIFFICULTY BELIEVING WE
WILL BE ABLE TO MUSTER MUCH IN THE WAY OF ANY AFTERNOON CONVECTION.
WITH THAT SAID...THE CHANCE IS NOT COMPLETELY ZERO WITH A LIGHT
WIND/LAKE BREEZE REGIME FAVORING ENHANCED CONVERGENCE INTO THE
SLUGGISH SYNOPTIC BOUNDARY...AND AT LEAST DECENT HEATING ACROSS
NORTHEAST LOWER AND THE HIGHER TERRAIN.
THEREAFTER...JUST CANNOT JUSTIFY HAVING ANY POPS IN THE FORECAST
BEYOND FRIDAY EVENING...AS THE ENTIRE PATTERN SLOWLY RETROGRADES AND
THE BEST MOISTURE AXIS SLIPS WELL TO OUR WEST...ALL WHILE AN
INCREASINGLY DRY BOUNDARY LAYER MAKES AN APPEARANCE THROUGH THE
WEEKEND. LOOKING INTO NEXT WEEK...DEEPER MOISTURE AXIS SHOULD REMAIN
WELL TO OUR SOUTH AS THE UPPER LOW PINWHEELS THROUGH THE TENNESSEE
VALLEY (OR SOMEWHERE NEAR THERE)...WITH DRY EASTERLY FLOW PREVAILING
UP THIS WAY AND SUBSIDENCE ON THE NORTHERN FRINGE OF CLOSED LOW
FEATURE FAVORING LOTS OF SUNSHINE. HIGHS SHOULD RESPOND NICELY INTO
THE 60S TO MIDDLE 70S EACH AFTERNOON...COOLER NEAR THE LAKESHORES OF
COURSE WHERE LAKE BREEZE DEVELOPMENT IS LIKELY EACH DAY GIVEN A VERY
WEAK GRADIENT IN PLACE. OVERNIGHT LOWS ARE A BIT MORE TRICKY IN THIS
LIGHT GRADIENT SETUP...AS DAILY MIXING OF DEW POINTS INTO THE 40S
AND MAYBE 30S AND CLEAR SKIES SHOULD EASILY ALLOW READINGS TO DIP
QUICKLY AFTER SUNSET. SIMPLY PUT...THE WEATHER THROUGH NEXT WEEK
LOOKS DOWNRIGHT SPECTACULAR FOR ALL OF NORTHERN MICHIGAN...WITH WARM
SUNNY DAYS AND COOL COMFORTABLE NIGHTS. ENJOY!
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1250 AM EDT THU MAY 2 2013
VFR. -SHRA POSSIBLE TO LIKELY THURSDAY AFTERNOON/EVENING MBL/TVC/PLN.
STALLING FRONT A BIT SE OF APN/HTL TONIGHT. SOME MID CLOUDS HAVE
DEVELOPED BEHIND THE FRONT (CIGS 6-10K FT). THIS DECK WILL BE
SOMEWHAT SPORADIC UNTIL THU AFTERNOON...WHEN CLOUDS WILL THICKEN
(ESPECIALLY IN NW LOWER AND THE STRAITS REGION). SOME -SHRA WILL
DEVELOP FROM THIS DECK IN THE AFTERNOON AND EVENING. MBL/TVC/PLN ALL
HAVE SOME MIX OF -SHRA AND/OR VCSH IN THE TAF IN THE AFTERNOON/
EVENING. WILL KEEP CONDITIONS VFR FOR NOW...THOUGH ANY PLACE THAT
GETS DECENTLY WET LATE THURSDAY WILL BE AT AN ENHANCED RISK TO SEE
FOG/STRATUS FORM THURSDAY NIGHT.
NORTHERLY BREEZES WILL CONTINUE AT MBL/TVC/PLN...WITH AN EAST WIND
FOR MOST OF THE FORECAST AT APN.
&&
.MARINE...
ISSUED AT 421 AM EDT THU MAY 2 2013
STATIONARY FRONT BISECTING LOWER MICHIGAN FROM NORTH TO SOUTH WILL
PRODUCE VERY DIFFERENT WIND CONDITIONS BETWEEN WHITEFISH BAY/LAKE
MICHIGAN AND LAKE HURON NEARSHORE ZONES...EVEN ON LAKE HURON
CONDITIONS WILL VARY QUITE A BIT. WESTERN ZONES WILL BE DEALING
WITH A STRONGER NORTHERLY GRADIENT ON THE COOLER SIDE OF THE
BOUNDARY...MAY PUSH SMALL CRAFT CONDITIONS WITHIN NORTHWEST LOWER
NEARSHORE ZONES. ON LAKE HURON...WINDS WILL VARY FROM A NORTHERLY
COMPONENT NORTH OF THUNDER BAY...AND A SOUTHERLY COMPONENT SOUTH
THOUGH BOTH AREAS WILL BE IMPACTED LOCALLY BY LAKE BREEZE COMPONENTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LMZ323-
344>346.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...DL
SHORT TERM...JPB
LONG TERM...DL
AVIATION...JZ
MARINE...JPB
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
1018 AM EDT THU MAY 2 2013
.SYNOPSIS...
ISSUED AT 421 AM EDT THU MAY 2 2013
A STRONG LOW PRESSURE SYSTEM WILL TAKE SHAPE ACROSS THE CENTRAL
PLAINS AND MID MISSISSIPPI VALLEY THROUGH THE WEEKEND...AS UPPER
LEVEL HIGH PRESSURE REMAINS PARKED ACROSS THE GREAT LAKES AND
NORTHEAST STATES. THIS WEATHER PATTERN WILL YIELD CONTINUED MILD
TEMPERATURES RIGHT ON THROUGH THE WEEKEND...WITH JUST A FEW SMALL
CHANCES FOR MAINLY AFTERNOON RAIN SHOWERS. DRY BUT CONTINUED WARM
WEATHER IS EXPECTED FOR MUCH OF NEXT WEEK...AS HIGH PRESSURE REMAINS
IN CONTROL ACROSS THE GREAT LAKES.
&&
.UPDATE...
ISSUED AT 1018 AM EDT THU MAY 2 2013
CHANGES THIS HOUR: HAVE LOWERED HIGHS JUST A TAD AND DELAYED
SHOWER POTENTIAL TO PRIMARILY 18Z AND BEYOND. OTHERWISE...MINOR
CHANGES TO SKY TO ACCOUNT FOR STRATUS NEAR WHITEFISH POINT.
COOL FRONT SITS OVER THE CWA ATTM WITH 12Z APX RAOB SHOWING VERY
IMPRESSIVE...ALBEIT VERY SHALLOW SURFACE BASED INVERSION WITH T9
AT 19C AND +13C AT H8. BOUNDARY IS LIKELY TO MIX NORTH AND WEST
GIVEN AMPLE SURFACE BASED HEATING OVER NORTHERN LOWER HEADING INTO
EARLY AFTERNOON. SOME CAVEATS TO THIS...HOWEVER...INCLUDE
DEVELOPING MID CLOUDS FROM CAD TO CVX UNDER ISENTROPIC ASCENT AT
THIS LEVEL WHICH MAY HELP REINFORCE THE BOUNDARY IF IT CAN HOLD
TOGETHER. EXPECT THAT IT WILL NOT /OR MORE LIKELY THAT IT WILL
LIFT NORTH WITH TIME/...ALLOWING BOUNDARY TO PUSH TOWARDS THE
COAST OF NW LOWER. THIS SHOULD ALLOW TEMPS TO WORK TOWARDS
PREVIOUSLY FORECASTED HIGHS. CERTAINLY SOME TEMPERATURE BUST
POTENTIAL IN THE VICINITY OF WHERE THIS FRONT MIXES TO THIS
AFTERNOON /TVC-ACB-PLN/.
EARLY MORNING RAP SOUNDINGS HAVE A MUCH BETTER HANDLE ON MOISTURE
OVER ARRIVING AIRMASS FROM SOUTHEAST LOWER THAN THE NAM /12Z DTX
RAOB SHOWS 0C DEWPOINT AT H8...WITH 6C FROM THE NAM/. THE RESULT
OF THIS IS AN AFTERNOON CHARACTERIZED BY MORE MID 40S DEWPOINTS
THAN LOW 50S...REDUCING CONVECTIVE POTENTIAL. WILL THUS DELAY
POPS...BUT NOT PULL THEM AT THIS POINT...BUT AWAIT 12Z GUIDANCE
AND LATE MORNING OBSERVATIONAL TRENDS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 421 AM EDT THU MAY 2 2013
EARLY MORNING SURFACE ANALYSIS SHOWS A COLD/STATIONARY FRONT
EXTENDING FROM NORTHERN QUEBEC...SOUTHWEST ACROSS CENTRAL LOWER
MICHIGAN AND DOWN INTO NORTHWEST ILLINOIS/CENTRAL MISSOURI AND ON
INTO THE SOUTHERN PLAINS. THIS FRONT WAS ASSOCIATED WITH AN UPPER
LEVEL TROUGH ENCOMPASSING THE NATION`S MIDSECTION...AND ITS EASTWARD
PROGRESS WAS BEING IMPEDED BY A NARROW BUT HIGH AMPLITUDE BLOCKING
RIDGE OVER THE EASTERN THIRD OF THE NATION AND SUBSEQUENT TROUGHING
OVER THE WESTERN ATLANTIC. A 30-40 DEGREE TEMPERATURE CONTRAST
EXISTS ACROSS THE FRONT...WITH AN ELONGATED BAND OF POST-FRONTAL
RAIN AND SNOW FROM THE CENTRAL/SOUTHERN PLAINS NORTHWARD INTO THE
UPPER MISSISSIPPI VALLEY. CLOSER TO HOME...SCATTERED CONVECTION
DEVELOPED EARLIER ACROSS EASTERN UPPER MICHIGAN/NORTHERN LAKE
MICHIGAN...THE TAIL END OF A BAND OF SCATTERED SHOWERS AND
THUNDERSTORMS EXTENDING INTO NORTHEAST ONTARIO. OTHERWISE SKIES ARE
CLEAR/PARTLY CLOUDY ACROSS NORTHERN LOWER.
STURDY RIDGE TO THE EAST WILL KEEP THINGS IN A HOLDING PATTERN
TODAY...STATIONARY FRONT WILL LIKELY WAVER A BIT DUE TO MIXING AND
LAKE BREEZE EFFECTS...BUT IS GOING TO ESSENTIALLY BISECT LOWER
MICHIGAN FROM NORTH TO SOUTH THROUGH THE SHORT TERM PERIOD. THIS
PRODUCES A MYRIAD OF FORECAST ISSUES FOR TODAY AND TONIGHT WITH
REGARD TO PRECIP CHANCES...TEMPERATURES...AND WINDS.
PRECIP ISSUES TODAY ARE PROBABLY GOING TO BE SIMILAR TO THOSE OF
WEDNESDAY...THAT IS WILL THERE BE ENOUGH MOISTURE TO GENERATE
INSTABILITY ALONG THE FRONT. FIRST...EXPECT THE FRONT TO MIX BACK
TO THE WEST...PROBABLY BACK TOWARD GLR-GOV-CAD THOUGH NORTHERN END
OF THE FRONT WILL PROBABLY BE DEFORMED IN AN EAST-WEST DIRECTION AS
LAKE HURON BREEZE RAMPS UP. THERE ARE INDICATIONS IN THE FORECAST
SOUNDINGS...PARTICULARLY THE GFS...OF STRATUS DEVELOPING ON THE COOL
SIDE OF THE FRONT VERY SHORTLY. THERE AREN`T ANY INDICATIONS OF
SUCH AS YET...SO WILL START OUT BY DOWNPLAYING THIS IDEA INITIALLY.
CAN SEE THE POSSIBILITY OF LOW CLOUDS DEVELOPING LATER THIS MORNING
AS THERMAL CONTRAST TIGHTENS...SUCH A SCENARIO IS MORE LIKELY OVER
THE COLD WATERS OF LAKE MICHIGAN AND PERHAPS SPILLING INTO ADJACENT
LAKESHORE AREAS OF NORTHWEST LOWER. SO WITH THE FRONT BACKING
TOWARD NORTHWEST LOWER...WILL PROBABLY TAKE DEW POINTS REMAINING IN
THE LOWER 50S TO GENERATE AROUND 500J/KG MLCAPE. TOOK ALL AFTERNOON
YESTERDAY TO GENERATE ONE SHOWER DURING THE EARLY EVENING...WONDER
IF WE`LL BE FACING THE SAME ISSUE TODAY. CURRENT THINKING IS THAT
IT IS CLOSE ENOUGH TO JUSTIFY CHANCE AFTERNOON POPS ACROSS MUCH OF
INTERIOR NORTHERN LOWER. ANOTHER POSSIBILITY FOR NORTHWEST LOWER IS
THAT UNSTABLE WARM SECTOR PARCELS ARE PULLED UP THE FRONTAL ZONE AND
CONVECT ON THE COOL SIDE OF THE BOUNDARY (ALONG/WEST OF US-131
CORRIDOR). SO SEVERAL POSSIBILITIES HERE. AS FOR TEMPERATURES
TODAY...AGAIN WILL VARY WIDELY DEPENDING ON LOCATION RELATIVE TO THE
FRONT AND LAKE BREEZE ACTIVITY. DON`T SEE WHY TEMPERATURES ON THE
WARM SIDE OF THE BOUNDARY WON`T MAKE ANOTHER RUN AT 80+ TODAY AS
CLOUD COVER SHOULD NOT BE MUCH OF AN ISSUE. RECORD HIGHS ARE A BIT
WARMER THAN YESTERDAY (APN 86/2001...HTL 88/1959...GLR 85/1959)...
AND WILL TAKE SOME TIME TO MIX THROUGH THE FRONTAL INVERSION SO
SHOULD BE A LITTLE SLOWER TEMPERATURE CLIMB THIS MORNING.
FOR TONIGHT...WILL BE DEALING BOTH WITH DEEPER MOISTURE NUDGING INTO
WESTERN PORTIONS OF THE FORECAST AREA AS WELL AS ELEVATED
INSTABILITY AND CONTINUE WARM ADVECTION. MUCH OF THE MOISTURE WILL
BE ACROSS THE WESTERN HALF OF THE FORECAST AREA AND THUS HIGHER
POPS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 421 AM EDT THU MAY 2 2013
SPRING LOOKS LIKE IT`S HERE TO STAY FOR THE FORESEEABLE FUTURE...
WITH ACTUALLY VERY FEW FORECAST ISSUES NOTED THROUGH THE WEEKEND AND
MAJORITY OF NEXT WORK WEEK. OVERALL UPPER PATTERN IS PROGGED BY ALL
AVAILABLE MEDIUM RANGE GUIDANCE TO REMAIN HEAVILY BLOCKED UP AS
CLOSED LOW DEVELOPMENT TAKES PLACE OVER THE MID MISSISSIPPI
VALLEY...WHILE ANOTHER CLOSED LOW MEANDER OVER THE WESTERN
ATLANTIC...EFFECTIVELY PINNING A RATHER EXPANSIVE OMEGA-TYPE RIDGE
IN PLACE FROM FLORIDA RIGHT ON UP THROUGH THE GREAT LAKES AND MUCH
OF EASTERN CANADA. THAT RIDGE SHOULD INCREASINGLY BECOME CUT OFF
OVER THE NORTHERN TIER FOR THE FIRST PART OF NEXT WEEK...AS THE
CLOSED LOW WANDERS RATHER AIMLESSLY SOMEWHERE TO OUR SOUTH (EXACT
POSITION STILL TO BE DETERMINED). AS THAT OCCURS...PREVAILING SOUTH
TO SOUTHEASTERLY LOW LEVEL FLOW WILL CONTINUE TO TRANSPORT SOME
RATHER MILD AIR NORTHWARD AS A PERSISTENT THERMAL RIDGE FEATURE
HOLDS INTACT ACROSS THE GREAT LAKES...FAVORING SOME MORE MUCH NEEDED
(AND LET`S FACE IT...MUCH DESERVED) WARM SPRINGTIME WEATHER FOR THE
NORTH WOODS.
LOOKING AT SOME SPECIFICS...STALLED FRONTAL BOUNDARY/INVERTED
TROUGH AXIS REMAINS PROGGED TO RESIDE ACROSS THE AREA THROUGH
FRIDAY...EFFECTIVELY SPLITTING THE STATE IN HALF. GIVEN YESTERDAY`S
HISTORY WITH THIS BOUNDARY COUPLED WITH AN INCREASINGLY DRIER
BOUNDARY LAYER LIKELY TO BE SHUNTED INTO THE REGION ON SLOWLY
BACKING SOUTHEAST FLOW REGIME...HAVE SOME DIFFICULTY BELIEVING WE
WILL BE ABLE TO MUSTER MUCH IN THE WAY OF ANY AFTERNOON CONVECTION.
WITH THAT SAID...THE CHANCE IS NOT COMPLETELY ZERO WITH A LIGHT
WIND/LAKE BREEZE REGIME FAVORING ENHANCED CONVERGENCE INTO THE
SLUGGISH SYNOPTIC BOUNDARY...AND AT LEAST DECENT HEATING ACROSS
NORTHEAST LOWER AND THE HIGHER TERRAIN.
THEREAFTER...JUST CANNOT JUSTIFY HAVING ANY POPS IN THE FORECAST
BEYOND FRIDAY EVENING...AS THE ENTIRE PATTERN SLOWLY RETROGRADES AND
THE BEST MOISTURE AXIS SLIPS WELL TO OUR WEST...ALL WHILE AN
INCREASINGLY DRY BOUNDARY LAYER MAKES AN APPEARANCE THROUGH THE
WEEKEND. LOOKING INTO NEXT WEEK...DEEPER MOISTURE AXIS SHOULD REMAIN
WELL TO OUR SOUTH AS THE UPPER LOW PINWHEELS THROUGH THE TENNESSEE
VALLEY (OR SOMEWHERE NEAR THERE)...WITH DRY EASTERLY FLOW PREVAILING
UP THIS WAY AND SUBSIDENCE ON THE NORTHERN FRINGE OF CLOSED LOW
FEATURE FAVORING LOTS OF SUNSHINE. HIGHS SHOULD RESPOND NICELY INTO
THE 60S TO MIDDLE 70S EACH AFTERNOON...COOLER NEAR THE LAKESHORES OF
COURSE WHERE LAKE BREEZE DEVELOPMENT IS LIKELY EACH DAY GIVEN A VERY
WEAK GRADIENT IN PLACE. OVERNIGHT LOWS ARE A BIT MORE TRICKY IN THIS
LIGHT GRADIENT SETUP...AS DAILY MIXING OF DEW POINTS INTO THE 40S
AND MAYBE 30S AND CLEAR SKIES SHOULD EASILY ALLOW READINGS TO DIP
QUICKLY AFTER SUNSET. SIMPLY PUT...THE WEATHER THROUGH NEXT WEEK
LOOKS DOWNRIGHT SPECTACULAR FOR ALL OF NORTHERN MICHIGAN...WITH WARM
SUNNY DAYS AND COOL COMFORTABLE NIGHTS. ENJOY!
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1250 AM EDT THU MAY 2 2013
VFR. -SHRA POSSIBLE TO LIKELY THURSDAY AFTERNOON/EVENING MBL/TVC/PLN.
STALLING FRONT A BIT SE OF APN/HTL TONIGHT. SOME MID CLOUDS HAVE
DEVELOPED BEHIND THE FRONT (CIGS 6-10K FT). THIS DECK WILL BE
SOMEWHAT SPORADIC UNTIL THU AFTERNOON...WHEN CLOUDS WILL THICKEN
(ESPECIALLY IN NW LOWER AND THE STRAITS REGION). SOME -SHRA WILL
DEVELOP FROM THIS DECK IN THE AFTERNOON AND EVENING. MBL/TVC/PLN ALL
HAVE SOME MIX OF -SHRA AND/OR VCSH IN THE TAF IN THE AFTERNOON/
EVENING. WILL KEEP CONDITIONS VFR FOR NOW...THOUGH ANY PLACE THAT
GETS DECENTLY WET LATE THURSDAY WILL BE AT AN ENHANCED RISK TO SEE
FOG/STRATUS FORM THURSDAY NIGHT.
NORTHERLY BREEZES WILL CONTINUE AT MBL/TVC/PLN...WITH AN EAST WIND
FOR MOST OF THE FORECAST AT APN.
&&
.MARINE...
ISSUED AT 421 AM EDT THU MAY 2 2013
STATIONARY FRONT BISECTING LOWER MICHIGAN FROM NORTH TO SOUTH WILL
PRODUCE VERY DIFFERENT WIND CONDITIONS BETWEEN WHITEFISH BAY/LAKE
MICHIGAN AND LAKE HURON NEARSHORE ZONES...EVEN ON LAKE HURON
CONDITIONS WILL VARY QUITE A BIT. WESTERN ZONES WILL BE DEALING
WITH A STRONGER NORTHERLY GRADIENT ON THE COOLER SIDE OF THE
BOUNDARY...MAY PUSH SMALL CRAFT CONDITIONS WITHIN NORTHWEST LOWER
NEARSHORE ZONES. ON LAKE HURON...WINDS WILL VARY FROM A NORTHERLY
COMPONENT NORTH OF THUNDER BAY...AND A SOUTHERLY COMPONENT SOUTH
THOUGH BOTH AREAS WILL BE IMPACTED LOCALLY BY LAKE BREEZE COMPONENTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LMZ323-
344>346.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...DL
SHORT TERM...JPB
LONG TERM...DL
AVIATION...JZ
MARINE...JPB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1206 AM CDT THU MAY 2 2013
.UPDATE...
ISSUED AT 1011 PM CDT WED MAY 1 2013
THE POTENT COLD FRONT IS MAKING GOOD PROGRESS INTO THE NWRN
PORTION OF THE CWA AND AT 03Z WAS BI-SECTING LEWIS AND SHELBY
COUNTIES...THEN TRAILED PASS MOBERLY AND INTO WESTERN COOPER
COUNTY. THE PUSH/PROGRESS WAS QUITE A BIT AHEAD OF THE PREVIOUS
FORECAST AND A QUICK LOOK AT THE NEW NAM AND RECENT RUC SUGGEST IT
WILL CONTINUE ITS S/SEWD MARCH. THIS NECESSITATED QUITE A FEW
CHANGES IN THE TONIGHT AND THURSDAY GRIDS TO SPEED THINGS UP DUE
TO THE PREVIOUSLY SLOW FRONTAL PROGRESS. OTHERWISE...THE MAIN
AREA OF RAIN WILL REMAIN WEST OF THE CWA TONIGHT...DEEP INTO THE
COLD AIR. HOWEVER SCATTERED SHOWERS AND EVEN SOME THUNDERSTORMS
WILL BE POSSIBLE IN A CORRIDOR AHEAD OF THE COLD FRONT AND IN THE
WAKE OF THE COLD FRONT IN RESPONSE TO LOW LEVEL WAA/MOISTURE
CONVERGENCE VIA SELY LOW LEVEL FLOW.
GLASS
&&
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 405 PM CDT WED MAY 1 2013
EWD PUSH OF STRONG COLD FRONT ACROSS AREA WILL CONTINUE TO BE AT A
SNAILS PACE OVERNIGHT. HAVE GONE WITH A CONSENSUS OF
LOCALWRF...NAM...AND SREF FOR ITS MOVEMENT...WHICH SUGGESTS FRONT
WILL BE CREEPING THROUGH UIN AND COU AREAS DURING THE PREDAWN HOURS.
OBVIOUSLY OVERNIGHT LOWS WILL BE DETERMINED BY THE EARLY MORNING
FRONTAL POSITION....BUT IN GENERAL HAVE LEANED TOWARDS THE WARMER
GUIDANCE DUE TO THE SLOW FRONTAL MOVEMENT.
SPOTTY AMS CONVECTION OVER E OZARKS/S IL SHOULD BE DISSIPATING OVER
THE NEXT FEW HOURS. WE THEN HAVE INTRODUCED SOME SLIGHT CHANCE POPS
OVER NW SECTIONS OF THE CWA LATER THIS EVENING AND OVERNIGHT AS NAM
FORECAST SOUNDINGS ARE INDICATING A WINDOW OF OPPORTUNITY FOR SOME
ELEVATED CONVECTION IN THE VICINITY OF THE FRONT...BUT IN GENEARL
THINK THAT MOST OF THE AREA WILL BE IN FOR A RATHER LONG WAIT UNTIL
THE MORE SIGNIFICANT PRECIPITATION MOVES IN.
TRUETT
.LONG TERM...(THURSDAY THROUGH NEXT WEDNESDAY)
ISSUED AT 400 PM CDT WED MAY 1 2013
UNUSUAL WX PATTERN FOR EARLY MAY AS THE UPPER LEVEL TROUGH OVER THE
NRN PLAINS DEEPENS...EVENTUALLY CUTTING OFF OVER THE PLAINS THU NGT
AND DEEPENS FRI AND FRI NGT. THE MODELS STILL DIFFER ON THE
POSITION AND TRACK OF THE UPPER LEVEL LOW WITH THE GFS FURTHER S
COMPARED TO THE NAM AND ECMWF MODELS. THE STRONG COLD FRONT WILL
MOVE SLOWLY SEWD THROUGH OUR FORECAST AREA ON THU AS THE UPPER LEVEL
TROUGH DEEPENS OVER THE PLAINS. IT APPEARS THAT MOST OF THE
PRECIPITATION WILL CONTINUE TO BE POST FRONTAL WITH THE CHANCE OF
RAIN GRADUALLY INCREASING FROM NW TO SE ON THU WITH THE PROGRESSION
OF THE FRONT. TEMPERATURES SHOULD FALL DURING THE AFTN ACROSS MOST
OF OUR AREA...EXCEPT SWRN IL AS COLDER AIR FILTERS SEWD INTO THE
REGION BEHIND THE FRONT ALONG WITH LOW LEVEL CLOUD COVER AND
FAIRLY WIDESPREAD PRECIPITATION. SHOULD HAVE WIDESPREAD AND
POSSIBLY HEAVY RAINS THU NGT AND FRI AS THE UPPER LEVEL LOW
DEVELOPS AND DEEPENS W OF OUR AREA AND CAUSES A SFC LOW TO DEVELOP
ALONG THE FRONT. WILL ISSUE A HDROLOGIC OUTLOOK FOR MAINLY THE
PERIOD FROM THU NGT THROUGH FRI NGT AS RAINFALL AMOUNTS OF 1 TO 2
INCHES ARE EXPECTED WITH LOCALLY HIGHER AMOUNTS WHICH COULD LEAD
TO SOME FLOOD POTENTIAL AND RIVERS AND CREEKS COMING UP TO
BANKFULL. THE NAM MODEL APPEARS A LITTLE TOO COLD ON TEMPERATURES
THU NGT THROUGH FRI NGT AND FOR NOW WILL GO WITH A BLEND OF NAM
AND GFS MOS GUIDANCE. EVEN SO WE WILL EXPERIENCE MUCH COOLER
TEMPERATURES FOR THU NGT THROUGH FRI NGT AND WELL BELOW NORMAL FOR
EARLY MAY. THE BETTER THREAT FOR PRECIPITATION SHOULD SHIFT EWD
INTO IL FRI NGT AS A DRY SLOT MOVES N-NEWD INTO PORTIONS OF CNTRL
AND SERN MO. THE PRECIPITATION WILL LIKELY BE MORE SCATTERED AND
POSSIBLY LIGHTER ON SAT AS THE UPPER LEVEL LOW AND ASSOCIATED
OCCLUDED SFC LOW MOVES SLOWLY THROUGH SWRN MO PER THE NAM AND
ECMWF FORECASTS...THE GFS MODEL APPEARS A LITTLE TOO FAR S WITH
TRACK OF UPPER LEVEL LOW. WITH HAVE LINGERING SHOWERS SAT NGT AND
SUN AS THE UPPER LEVEL LOW MOVES SLOWLY EWD THROUGH SERN MO AND
SRN IL WITH CONTINUED UNSEASONABLY COLD TEMPERATURES. WILL BEGIN
TO SEE A WARMING TREND FOR THE EARLY PORTION OF THE NEXT WORK WEEK
AS THE UPPER LEVEL LOW FINALLY MOVES WELL E OF OUR AREA.
GKS
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1150 PM CDT WED MAY 1 2013
LATEST SURFACE ANAYLSIS SHOWS COLD FRONT MOVING MUCH FASTER TO THE
SOUTHEAST FROM EARLIER FORECASTS. COLD FRONT HAS ALREADY MOVED
SOUTH OF UIN AND VERY NEAR COU. EXPECT FROMO COLD FRONT TO MOVE
ACROSS THE ST. LOUIS AREA BETWEEN 1100-1300 UTC. CIGS WILL BE
DROPPING FROM DAYBREAK THROUGH MID DAY. EXPECT RAIN AND FOG TO
DEVELOP OVER COU BEFORE DAYBRAK AND OVER STL-SUS-UIN AREA DURING
LATE MORNING AND CONTINUE TO AFTERNOON HOURS. WINDS WILL BE
NORTHERLY 10 TO 12 KTS WITH GUSTS TO 14KTS FROM THE NORTH.
SPECIFICS FOR KSTL..CIGS WILL BE DROPPINJG TO 5 KFT AFTER 0900 UTC
AND 3 KFT AFTER 1000 UTC. WINDS WILL BE FROM THE SOUTHEAST AT
AROUND 7 KTS THEN AFTER PASSAGE OF COLD FRONT AROUND 1100 UTC
WINDS WILL SHIFT TO THE NORTH WITH SPEEDS OF 10 KTS AND POSSIBLE
GUSTS TO 14 KTS. RAINSHOWERS AND FOG WILL SETTLE OVER AREA AFTER
1500 UTC. LOW CIGS BELOW 1 KFT WILL OCCUR FROM MID AFTERNOON
THROUGH EVENING HOURS.
PRZYBYLINSKI
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BUFFALO NY
959 AM EDT THU MAY 2 2013
.SYNOPSIS...
HIGH PRESSURE IN PLACE ACROSS THE EASTERN STATES WILL REMAIN IN
CONTROL OF OUR WEATHER FOR THE REST OF THE WEEK. THIS WILL
PROVIDE US WITH PLENTY OF SUNSHINE AND WELL ABOVE AVERAGE
TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE BOTH AT THE SURFACE AND ALOFT WILL REMAIN IN CONTROL
OF OUR WEATHER THROUGH TONIGHT. ANOTHER SUNNY DAY TODAY WITH WARM AFTERNOON
TEMPERATURES IN THE MID 70S TO ABOUT 80...ALTHOUGH LAKESHORE AREAS
WILL BACK OFF FROM THESE NUMBERS ONCE THE LAKE BREEZES KICK IN.
UPDATED FORECAST GRIDS THIS MORNING WITH LATEST HRRR MODEL TEMPS
AND WINDS TO ACCOUNT FOR THE SHIFTING WINDS AND COOLING TEMPS ALONG
THE LAKE SHORES ONCE THE LAKE BREEZE SETS UP. THE LAKE BREEZE LOOKS
TO WORK INLAND ACROSS MOST OF ALL LAKE BORDERING COUNTIES BY LATE
AFTERNOON.
MODEL SUGGESTION OF SOME MID LEVEL MOISTURE ASSOCIATED WITH A SLIGHT
COOL DOWN ALOFT WILL PUSH THROUGH THE REGION FROM THE NORTHEAST
TONIGHT. AIR MASS TOO DRY FOR ANYTHING MORE THAN A PERIOD OF MID AND
HIGH LEVEL CLOUDS WITH THIS FEATURE. MILD TEMPS EXPECTED AGAIN
TONIGHT ONLY FALLING INTO THE UPPER 40S TO LOW 50S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
SURFACE HIGH PRESSURE COVERING MUCH OF THE EASTERN U.S. WILL BE
OVERLAIN BY A DEVELOPING OMEGA BLOCK. AN UPPER RIDGE WILL BE
CENTERED BETWEEN A CUTOFF LOW OVER THE CENTRAL PLAINS AND ANOTHER
CUTOFF LOW ACROSS THE WESTERN ATLANTIC.
850MB TEMPERATURES ACROSS THE REGION WILL RANGE FROM AROUND +8C ON
FRIDAY TO +6C SATURDAY WITH UPPER 60S TO THE LOWER 70S...AND SOUTH
TO SOUTHEAST WINDS WILL HELP BOOST THE HIGH TEMPS TO THE MID 70S
ACROSS THE LAKE PLAINS AND VALLEYS.
LOW TEMPERATURES WILL ALSO BE MILD THROUGH THE PERIOD...WITH LOWS IN
THE LOWER 50S ON THE LAKE PLAINS OF WESTERN NY...WITH 40S ACROSS THE
HIGHER TERRAIN AND SOME SPOTS EAST OF LAKE ONTARIO.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE EXCEPTIONAL PERIOD OF DRY AND WARM WEATHER WILL LAST AT LEAST
THROUGH THE WEEKEND AS AN OMEGA BLOCK REMAINS IN PLACE ACROSS THE
EASTERN STATES WITH HIGH PRESSURE SURFACE AND ALOFT. 850MB TEMPS
REMAIN AROUND +8C OR BETTER INTO THE WEEKEND...SUPPORTING HIGHS IN
THE MID 70S ACROSS LOWER ELEVATIONS. THERE MAY BE A LITTLE CLOUD
COVER AT TIMES AS A FEW WEAK BACKDOOR FRONTS WASH OUT ON THE
NORTHERN PERIPHERY OF THE RIDGE...BUT STILL EXPECT A DECENT AMOUNT
OF SUN AS WELL.
THE FORECAST BECOMES MUCH MORE UNCERTAIN EARLY NEXT WEEK AS MODEL
GUIDANCE DIVERGES WITH THE HANDLING OF A MIDWEST CUTOFF LOW.
GUIDANCE HAS BEEN ALL OVER THE PLACE WITH THIS...AND IT IS NOT
UNUSUAL FOR GUIDANCE TO STRUGGLE WITH CUTOFF LOWS. BECAUSE OF THIS
SPREAD IN GUIDANCE...WILL AVOID FOCUSING ON ANY ONE MODEL OR RUN.
KEEPING THIS IN MIND...THE MAJORITY OF GUIDANCE KEEPS OUR AREA DRY
EARLY NEXT WEEK...WITH ONLY A MARGINAL CHANCE FOR SHOWERS AND COOLER
TEMPERATURES. CHANCES GRADUALLY INCREASE TOWARD MID-WEEK BUT STILL
ARE QUITE LOW. THE 00Z EUROPEAN SHOWED A SIGNIFICANT COLD FRONT
CROSSING ON WEDNESDAY...BUT THE MAJORITY OF OTHER GUIDANCE (06/12Z
GFS AND THE 12Z EURO) CONTINUE TO SHOW A BROAD RIDGE IN THE
EAST...WITH THE CUT-OFF LOW STILL LINGERING IN THE AREA.
TEMPERATURES SHOULD REMAIN ABOVE NORMAL THROUGH WEDNESDAY...AND THE
WARM WEATHER COULD EVEN LAST LONGER IF THE MAJORITY OF THE LONG
RANGE GUIDANCE IS CORRECT.
ENJOY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL CONTINUE TO BRING VFR CONDITIONS TO THE FORECAST
AREA THROUGH AT LEAST TONIGHT. MAINLY SKC CONDITIONS TODAY WILL
GIVE WAY TO SOME MID LEVEL CLOUDS TONIGHT...MAINLY IMPACTING THE
KART AND KROC TERMINALS. LIGHT SOUTHEASTERLY WINDS WILL GIVE WAY TO
THE USUAL LAKE BREEZES THIS AFTERNOON WITH ALL TAFS BUT KJHW SEEING
WINDS SHIFT FROM THE LAKE TODAY THEN RETURN BACK SO SOUTHEASTERLY
AFTER LATER THIS EVENING.
OUTLOOK...
FRIDAY THROUGH MONDAY...VFR.
&&
.MARINE...
HIGH PRESSURE DOMINATING THE NORTHEASTERN UNITED STATES WILL PERSIST
THROUGH THE WEEKEND WITH LIGHT SOUTHEASTERLY FLOW RESULTING IN
TRANQUIL CONDITIONS ON THE LAKES. LAKE BREEZES WILL SET UP IN THE
EACH AFTERNOON.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TMA
NEAR TERM...SMITH
SHORT TERM...WCH
LONG TERM...APFFEL
AVIATION...SMITH
MARINE...SMITH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
954 PM EDT FRI MAY 3 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN CENTERED ALONG THE NEW ENGLAND COAST
INTO THIS WEEKEND. A FRONTAL SYSTEM IN THE MISSISSIPPI VALLEY WILL
MOVE SLOWLY EAST...EVENTUALLY MOVING INTO THE CAROLINAS EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 950 PM FRIDAY...LATEST RAP MODEL CONTINUES TO SHOW LIGHT
PRECIPITATION REMAINING JUST OFFSHORE AS WEAKNESS IN PRESSURE
FIELD CONTINUES OFFSHORE. WILL CONTINUE A SLIGHT CHC POP TO
ACCOUNT FOR ANY SHOWERS TAKE MAY SNEAK ONSHORE OVERNIGHT. MAIN
CHANGE TO CURRENT FORECAST WILL BE TO LOWER MINIMUM TEMPERATURES A
COUPLE OF DEGREES BASED ON CURRENT FORECASTS AND FAIRLY LOW
DEWPOINT TEMPERATURES IN THE 40S. WITH BREEZY NORTHEAST WINDS...TEMPS
WILL FEEL EVEN COOLER OVERNIGHT...CERTAINLY NOT MAY-LIKE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
AS OF 3 PM FRI...NO SIGNIFICANT PATTERN CHANGE EXPECTED FOR SAT
WITH HIGH PRESSURE TO THE NORTH...LOW TO THE SOUTH...AND UPPER LOW
MOVING INTO THE SE STATES. BREEZY CONDITIONS EXPECTED AGAIN WITH
TIGHTENED GRADIENT. BASED ON LATEST GUIDANCE WILL CONTINUE POPS
FOR SAT...MAINLY E OF HWY 17 WITH CONTINUED ONSHORE FLOW AND WEAK
IMPULSE MOVING THROUGH AHEAD OF THE UPPER LOW. WILL CAP AT SLIGHT
CHANCE FOR NOW. SIMILAR HIGH TEMPS EXPECTED GENERALLY MID 60S TO
LOW 70S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
OMEGA BLOCK WILL HOLD THRU SAT NIGHT WITH AXIS OF UPPER RDG OVER
THE AREA. BLOCK BREAKS DOWN LATER SUNDAY THRU EARLY NEXT WEEK AS
UPR LOW TO THE W SLIDES E AND UNDERCUTS THE RDG. MUCH OF THE
SUPPORT FOR STEADIER RAIN WILL REMAIN W OF REGION THRU SUN BUT A
SLIGHT TO LOW CHANCE POP OVER SOUTHERN AREAS SAT NIGHT WITH LOW
CHC POPS SPREADING NORTH THRU THE DAY ON SUNDAY AS AN AXIS OF
DEEPER MOISTURE LIFTS NORTH ACRS EASTERN NC. RAIN CHC INCREASE
SUN NIGHT AND ESPCLY MON AS BETTER FORCING AND MOISTURE AHEAD OF
UPPER LOW MOVES INTO REGION. DECENT AGREEMENT AMONG THE LATEST
MODEL RUNS FOR THE UPR LOW DRIFTING THRU THE SE STATES EARLY IN
THE WEEK THEN LIFTING NE ACRS THE FORECAST AREA ON WEDNESDAY SO
EXPECT PROLONGED PERIOD OF UNSETTLED WEATHER THRU MIDWEEK. KEPT
MENTION OF TSRA MAINLY DURING PEAK DIURNAL HEATING CYCLE MON-WED
GIVEN THE COOL POOL ALOFT. BEST LOW LVL WINDS ACROSS REGION MON
HOWEVER INSTAB LOOK WEAK. LOW LVL WINDS BECOME RATHER LIGHT TUE
AND WED HOWEVER WITH COLD POOL ALOFT MAY SEE DECENT CONVECTION
ESPCLY IF GET SOME SUN. OVERALL SEVERE THREATS LOOKS LIMITED BUT
NOT ZERO FIRST PART OF NEXT WEEK. HAVE RAMPED UP POPS TO LIKELY
MOST AREAS ON MON AND MAY NEED TO CONTINUE THE HIGHER POP TREND
INTO TUE IF MODELS CONTINUE IN GOOD AGREEMENT. DRYING TREND WILL
TAKE HOLD LATER IN THE WEEK AS THE UPR LOW FINALLY MOVES WELL NE
OF THE AREA.
TEMPS WILL BE BELOW NORMAL EARLY IN THE WEEK WITH HIGHS MAINLY
UPR 60S TO LOWER 70S. WARMING TREND WILL HIGHLIGHT THE MID TO LATE
WEEK PERIOD WITH AN UPPER RIDGE AGAIN BUILDING OVER THE AREA.
HIGHS MAY REACH NEAR 80 INLAND BY FRIDAY.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH SATURDAY/...
AS OF 705 PM FRI...MODERATE CONFIDENCE THAT SOME MVFR AND PERHAPS
IFR CEILINGS WILL OCCUR TOWARD MORNING PER LATEST NUMERICAL
GUIDANCE AND PERSISTENCE FROM THE LAST FEW DAYS WITH LITTLE CHANGE
IN THE AIRMASS. BY MORNING...CONDITIONS WILL LIFT TO VFR AFTER
SUNRISE.
LONG TERM /SAT NIGHT THROUGH WEDNESDAY/...
GENERALLY VFR CONDITIONS SHOULD PREVAIL EARLY IN THE PERIOD BUT
FLYING CONDITIONS WILL DETERIORATE AS SHOWERS BECOME MORE
NUMEROUS LATE IN THE WEEKEND AND ESPECIALLY EARLY NEXT WEEK AHEAD
OF APPROACHING UPPER LOW.
&&
.MARINE...
SHORT TERM /THROUGH SATURDAY/...
AS OF 950 PM FRIDAY...GUSTY NORTHEAST WINDS CONTINUE ON AREA
WATERS WITH 1030+ MB HIGH HOLDING FIRM OVER CENTRAL NEW ENGLAND.
WINDS ARE GUSTING AS HIGH AS 32 KNOTS AT CAPE LOOKOUT WITH SEAS AS
HIGH AS 9 FEET AT THE BUOY 10 MILES NE OF DUCK. HAVE MADE JUST
MINOR TWEAKS TO THE MARINE FORECAST BASED ON CURRENT OBSERVATIONS
AS THE GUSTY WINDS AND ROUGH SEAS WILL CONTINUE THROUGH THE SHORT-
TERM PERIOD.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
POOR BOATING CONDITIONS MOST OF THE PERIOD. GUSTY NE WINDS CONT
SAT NIGHT WITH STRONG HIGH PRES TO THE N AND LOW PRES WELL TO THE
S. THE SFC LOW WILL GRAD LIFT N INTO MON AS UPR LOW APPROACHES
FROM THE W. WINDS WILL GRAD BECOME MORE E SUN TO SE MON WITH
SPEEDS INCREASING INTO THE 15 TO 20 KT RANGE. THE SFC LOW WILL
DRIFT OVER THE AREA BY TUE WITH WINDS BECOMING S/SW LESS THAN 15
KTS. THE LONG DURATION OF ONSHORE FLOW WILL KEEP SEAS ELEVATED
ABOVE SMALL CRAFT ADVISORY THRESHOLDS THRU AT LEAST TUESDAY.
&&
.TIDES/COASTAL FLOODING...
NE WINDS 20-30 MPH HAVE YIELDED REPORTS OF WATER LEVEL RISES OF
UP TO 3.5 FT ABV NORMAL ALONG CLUBFOOT CREEK, BACK CREEK AND AT
THE CHERRY BRANCH FERRY ON THE NEUSE RIVER EARLIER THIS
AFTERNOON. A REPORT FROM BACK CREEK TONIGHT SHOWS LEVEL HOLDING
STEADY AT 2.5 FEET ABOVE NORMAL. COASTAL FLOOD ADVISORY IS IN
EFFECT FOR CRAVEN AND CARTERET COUNTIES INTO EARLY SATURDAY
MORNING. WINDS WILL DECREASE SOMEWHAT TOWARD MORNING AND THAT
SHOULD ALLOW WATER LEVELS TO RECEDE ON SATURDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...BEACH HAZARDS STATEMENT THROUGH SATURDAY EVENING FOR NCZ095-
103-104.
COASTAL FLOOD ADVISORY UNTIL 2 AM EDT SATURDAY FOR NCZ093-095.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT SATURDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT SATURDAY FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL NOON EDT TUESDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...CQD
NEAR TERM...CTC
SHORT TERM...CQD
LONG TERM...BTC/RF
AVIATION...CTC/BTC/BM
MARINE...CTC/RF/CQD
TIDES/COASTAL FLOODING...BTC/CTC
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
712 PM EDT FRI MAY 3 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN CENTERED ALONG THE NEW ENGLAND COAST
INTO THIS WEEKEND. A FRONTAL SYSTEM IN THE MISSISSIPPI VALLEY WILL
MOVE SLOWLY EAST...EVENTUALLY MOVING INTO THE CAROLINAS EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 705 PM FRIDAY...NO MAJOR CHANGES TO CURRENT FORECAST. WEAK
TROUGH WILL LINGER OFFSHORE AND PER LATEST RAP AND 4KM
WRF...CANNOT RULE OUT AN ISOLATED SHOWER OR TWO ALONG THE COAST
AND HAVE KEPT SLIGHT CHANCE POP IN THAT AREA. WITH MODERATE TO
STRONG NE BREEZE...IT WILL BE A RATHER CHILLY NIGHT FOR MAY AS LOW
TEMPS DROP INTO THE 50S WITH PERHAPS A FEW UPPER 40S IN NORMALLY
COOLER SPOTS INLAND TOWARD MORNING.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
AS OF 3 PM FRI...NO SIGNIFICANT PATTERN CHANGE EXPECTED FOR SAT
WITH HIGH PRESSURE TO THE NORTH...LOW TO THE SOUTH...AND UPPER LOW
MOVING INTO THE SE STATES. BREEZY CONDITIONS EXPECTED AGAIN WITH
TIGHTENED GRADIENT. BASED ON LATEST GUIDANCE WILL CONTINUE POPS
FOR SAT...MAINLY E OF HWY 17 WITH CONTINUED ONSHORE FLOW AND WEAK
IMPULSE MOVING THROUGH AHEAD OF THE UPPER LOW. WILL CAP AT SLIGHT
CHANCE FOR NOW. SIMILAR HIGH TEMPS EXPECTED GENERALLY MID 60S TO
LOW 70S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
OMEGA BLOCK WILL HOLD THRU SAT NIGHT WITH AXIS OF UPPER RDG OVER
THE AREA. BLOCK BREAKS DOWN LATER SUNDAY THRU EARLY NEXT WEEK AS
UPR LOW TO THE W SLIDES E AND UNDERCUTS THE RDG. MUCH OF THE
SUPPORT FOR STEADIER RAIN WILL REMAIN W OF REGION THRU SUN BUT A
SLIGHT TO LOW CHANCE POP OVER SOUTHERN AREAS SAT NIGHT WITH LOW
CHC POPS SPREADING NORTH THRU THE DAY ON SUNDAY AS AN AXIS OF
DEEPER MOISTURE LIFTS NORTH ACRS EASTERN NC. RAIN CHC INCREASE
SUN NIGHT AND ESPCLY MON AS BETTER FORCING AND MOISTURE AHEAD OF
UPPER LOW MOVES INTO REGION. DECENT AGREEMENT AMONG THE LATEST
MODEL RUNS FOR THE UPR LOW DRIFTING THRU THE SE STATES EARLY IN
THE WEEK THEN LIFTING NE ACRS THE FORECAST AREA ON WEDNESDAY SO
EXPECT PROLONGED PERIOD OF UNSETTLED WEATHER THRU MIDWEEK. KEPT
MENTION OF TSRA MAINLY DURING PEAK DIURNAL HEATING CYCLE MON-WED
GIVEN THE COOL POOL ALOFT. BEST LOW LVL WINDS ACROSS REGION MON
HOWEVER INSTAB LOOK WEAK. LOW LVL WINDS BECOME RATHER LIGHT TUE
AND WED HOWEVER WITH COLD POOL ALOFT MAY SEE DECENT CONVECTION
ESPCLY IF GET SOME SUN. OVERALL SEVERE THREATS LOOKS LIMITED BUT
NOT ZERO FIRST PART OF NEXT WEEK. HAVE RAMPED UP POPS TO LIKELY
MOST AREAS ON MON AND MAY NEED TO CONTINUE THE HIGHER POP TREND
INTO TUE IF MODELS CONTINUE IN GOOD AGREEMENT. DRYING TREND WILL
TAKE HOLD LATER IN THE WEEK AS THE UPR LOW FINALLY MOVES WELL NE
OF THE AREA.
TEMPS WILL BE BELOW NORMAL EARLY IN THE WEEK WITH HIGHS MAINLY
UPR 60S TO LOWER 70S. WARMING TREND WILL HIGHLIGHT THE MID TO LATE
WEEK PERIOD WITH AN UPPER RIDGE AGAIN BUILDING OVER THE AREA.
HIGHS MAY REACH NEAR 80 INLAND BY FRIDAY.
&&
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH SATURDAY/...
AS OF 705 PM FRI...MODERATE CONFIDENCE THAT SOME MVFR AND PERHAPS
IFR CEILINGS WILL OCCUR TOWARD MORNING PER LATEST NUMERICAL
GUIDANCE AND PERSISTENCE FROM THE LAST FEW DAYS WITH LITTLE CHANGE
IN THE AIRMASS. BY MORNING...CONDITIONS WILL LIFT TO VFR AFTER
SUNRISE.
LONG TERM /SAT NIGHT THROUGH WEDNESDAY/...
GENERALLY VFR CONDITIONS SHOULD PREVAIL EARLY IN THE PERIOD BUT
FLYING CONDITIONS WILL DETERIORATE AS SHOWERS BECOME MORE
NUMEROUS LATE IN THE WEEKEND AND ESPECIALLY EARLY NEXT WEEK AHEAD
OF APPROACHING UPPER LOW.
&&
.MARINE...
SHORT TERM /THROUGH SATURDAY/...
AS OF 710 PM FRI...NO BIG CHANGES TO CURRENT MARINE FORECAST.
WINDS GUSTING WELL INTO THE 20S AT A FEW OF THE BUOY SITES WITH
SEAS AS HIGH AS 8 FEET AT THE BUOY 10 FEET NE OF DUCK AND 13 MILES
EAST OF OREGON INLET. SMALL CRAFT CONTINUES ON THE SOUNDS INTO
SATURDAY AND OVER THE COASTAL WATERS IN EARLY NEXT WEEK.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
POOR BOATING CONDITIONS MOST OF THE PERIOD. GUSTY NE WINDS CONT
SAT NIGHT WITH STRONG HIGH PRES TO THE N AND LOW PRES WELL TO THE
S. THE SFC LOW WILL GRAD LIFT N INTO MON AS UPR LOW APPROACHES
FROM THE W. WINDS WILL GRAD BECOME MORE E SUN TO SE MON WITH
SPEEDS INCREASING INTO THE 15 TO 20 KT RANGE. THE SFC LOW WILL
DRIFT OVER THE AREA BY TUE WITH WINDS BECOMING S/SW LESS THAN 15
KTS. THE LONG DURATION OF ONSHORE FLOW WILL KEEP SEAS ELEVATED
ABOVE SMALL CRAFT ADVISORY THRESHOLDS THRU AT LEAST TUESDAY.
&&
.TIDES/COASTAL FLOODING...
NE WINDS 20-30 MPH HAVE YIELDED REPORTS OF WATER LEVEL RISES OF
UP TO 3.5 FT ABV NORMAL ALONG CLUBFOOT CREEK, BACK CREEK AND AT
THE CHERRY BRANCH FERRY ON THE NEUSE RIVER THIS AFTERNOON. WILL
ISSUE A COASTAL FLOOD ADVISORY FOR CRAVEN AND CARTERET COUNTIES
INTO EARLY SATURDAY MORNING. WINDS WILL DECREASE SOMEWHAT TONIGHT
AND ALLOW WATER LEVELS TO RECEDE ON SATURDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...BEACH HAZARDS STATEMENT THROUGH SATURDAY EVENING FOR NCZ095-
103-104.
COASTAL FLOOD ADVISORY UNTIL 2 AM EDT SATURDAY FOR NCZ093-095.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT SATURDAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT SATURDAY FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL NOON EDT TUESDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...CQD
NEAR TERM...CTC
SHORT TERM...CQD
LONG TERM...BTC/RF
AVIATION...CTC/BTC/BM
MARINE...CTC/RF/CQD
TIDES/COASTAL FLOODING...BTC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
630 PM EDT THU MAY 2 2013
.SYNOPSIS...
INTERVALS OF LIGHT RAIN AND DRIZZLE WILL CONTINUE TO MOVE ONSHORE
FROM TIME TO TIME THROUGH SATURDAY. A MORE SIGNIFICANT STORM
SYSTEM WILL AFFECT THE REGION NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 615 PM THURSDAY...THIS UPDATE MAINLY CONCERNED WITH PCPN
COVERAGE THIS EVENING AND OVERNIGHT. BASED ON LATEST KLTX AND
SURROUNDING 88DS...AND THE LATEST HRRR OUTPUT...PCPN IN THE FORM
OF STRATIFORM R- AND L- TO MOVE FROM ENE TO WSW ACROSS THE FA
EARLY INTO THE MID-EVENING HOURS. WILL BASICALLY DROP POPS BELOW
15 PERCENT ACROSS INLAND LOCATIONS OVERNIGHT...BUT KEEP SLIGHT
CHANCE ALONG THE IMMEDIATE COAST FOR ANY ONSHORE MOVEMENT. NO
CHANGES TO OVERNIGHT TEMPS AT THIS POINT.
PREVIOUS DISCUSSION.............................................
AS OF 230 PM THURSDAY...MOIST NORTHEASTERLY FLOW WILL CONTINUE
THROUGH THE NEAR TERM AS HIGH PRESSURE PRESSES DOWN FROM THE
NORTH. LOW LEVEL CONVERGENCE ALONG THE COAST ALLOWING PATCHES OF
LIGHT RAIN AND DRIZZLE TO FORM AND MOVE INLAND. THIS PATTERN WILL
CONTINUE FOR THE REMAINDER OF THE AFTERNOON. NOT MUCH CHANGES FOR
TONIGHT OTHER THAN SOME ADDITIONAL DRYING AT THE MID LEVELS.
HOWEVER...AS PRESENT PRECIPITATION REGIME IS PRIMARILY A STRATUS
EVENT...WILL BE KEEPING IN THE CHANCE FOR ADDITIONAL LIGHT RAIN
AND DRIZZLE INTO THE NIGHT-TIME HOURS...WITH THE BEST CHANCES
ALONG THE COAST. A CONSENSUS OF GUIDANCE GIVES US OVERNIGHT
TEMPERATURES NOT FAR FROM CLIMO...MID 50S INLAND AND UPPER 50S
CLOSER TO THE COAST.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...MAIN FORECAST CHALLENGE IS THE POSSIBILITY
OF THE INTERVALS OF NUISANCE RAIN/DRIZZLE CONTINUING FOR THE NEXT
COUPLE OF DAYS. ALTHOUGH THERMAL PROFILES CONTINUE TO DRY
OUT...THE FACT THAT THE NATURE OF THE SHOWERS HAS BEEN AND IS VERY
SHALLOW. THIS ALMOST GOES WITHOUT SAYING WITH DRIZZLE. THE
GFS...NAM AS WELL AS SREF PLUME DIAGRAMS SHOW SMALL AREAS OF QPF
INDICATIVE OF THIS ACTIVITY CONTINUING THROUGH
SATURDAY...THEREFORE...I HAVE ADDED THIS TO THE FORECAST. TIMING
IS DIFFICULT BUT LEANED TOWARD THE NAM TO SHOW AN INCREMENTAL
DIFFERENCE WITH A SLIGHT INCREASE BOTH FRIDAY AND SATURDAY
MORNINGS. ONLY SMALL CHANGES TO TEMPERATURE FORECAST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...CLIMATOLOGICALLY UNUSUAL SETUP THROUGH MOST OF
THE PERIOD MAKING FOR SOME INTERESTING AND CHALLENGING FORECASTS.
DEEP CUTOFF UPPER LOW WILL APPROACH AND EVENTUALLY TRAVERSE THE
CAROLINAS...WHICH IS MUCH MORE TYPICAL OF WINTER OR MUCH EARLIER IN
THE SPRING. IT IS MORE THE ISOLATION FROM THE FLOW OF THIS FEATURE
RATHER THAN ITS UNUSUAL TIMING THAT MAKES THE FORECAST CHALLENGING
SINCE SUCH FEATURES ARE USUALLY POORLY HANDLED BY MODEL GUIDANCE.
THAT SAID THE MODELS HAVE COME INTO PRETTY GOOD AGREEMENT WITH THE
EVOLUTION OF THE PATTERN. THERE WILL STILL BE SOME FUTURE
REFINEMENTS IN THE TIMING POSSIBLE AND THE WEATHER ITSELF WILL BE
QUITE COMPLEX AS WE SHOULD GO THROUGH SOME DISTINCT REGIME CHANGES
THROUGH THE PERIOD. SUNDAY APPEARS TO BE THE LAST DAY IN THE
PRE FRONTAL FLOW AHEAD OF THE UPPER LOW. MOISTURE WILL BE RAPIDLY ON
THE RISE ESP ACCORDING TO THE RELATIVELY FASTER GFS. BEST FORCING IN
THE FORM OF MID LEVEL JETTING AND HEIGHT FALLS COME EITHER LATE
SUNDAY OR SUNDAY NIGHT INTO MONDAY AGAIN DEPENDING ON MODEL SOLN.
RAINFALL CHANCES AND QPF POTENTIAL ARE STARTING TO LOOK PRETTY GOOD
WITH SUCH STRONG FORCING AND DEEP ATLANTIC MOISTURE EXPECTED. THEN
THE SYNOPTIC SCALE DRY SLOT WILL MOVE ACROSS THE AREA SHUTTING OFF
THE RAINFALL FOR ABOUT A PERIOD. WE WILL THEN MOVE INTO A VERY
CONVECTIVE REGIME AS THE COLD POOL ALOFT CRAWLS ACROSS THE REGION.
RIGHT NOW BEST ESTIMATE IS THIS IS TUESDAY...WHICH COULD BE A BUSY
DAY WITH A RADAR SCOPE FULL OF SMALL HAIL PRODUCING SHALLOW TSTMS.
RAIN CHANCES WILL BE SMALLER FOR THE REMAINDER OF THE PERIOD AS THE
SLOW MOVING SYSTEM COULD STILL PLAGUE THE COASTAL CAROLINAS WITH
WRAP-AROUND MOISTURE.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...MVFR WITH AREAS OF VFR WILL CONTINUE THROUGH THE
EVENING HOURS DUE TO LOWERED CIGS. INTO THE OVERNIGHT
HOURS...MVFR RETURNS WITH POSSIBLE IFR DUE TO LOWERED CIGS ONCE
AGAIN.
ISOLATED SHOWERS CONTINUE TO MOVE ONSHORE THIS AFTERNOON WITH
WIDESPREAD MVFR...AND AREAS OF VFR...AND EAST-NORTHEAST WINDS AOB
15 KTS. INTO THE LATER AFTERNOON HOURS COULD SEE SOME MORE AREAS
IMPROVE TO VFR...INITIALLY AT THE COAST AND THEN WESTWARD TO THE
INLAND SITES AS DRIER AIR USHERS INTO THE AREA. FCST SOUNDINGS AND
TIME-HEIGHT ANALYSIS ARE IN DECENT AGREEMENT FOR THE RETURN OF
LOWERED CIGS LATE OVERNIGHT INTO THE MORNING HOURS. ANTICIPATE
MVFR...BUT CANNOT RULE OUT IFR. CONDITIONS WILL GRADUALLY IMPROVE
TO VFR AGAIN TOWARDS THE END OF THE VALID PERIOD.
AS FOR WINDS...EXPECT EAST-NORTHEAST WINDS 12-15 KTS TO
CONTINUE...WITH GUSTS UP TO 25 KTS POSSIBLE THIS AFTERNOON. GUSTS
WILL SUBSIDE INTO THE EVENING HOURS...BUT ANTICIPATE EAST WINDS TO
CONTINUE AOB 12 KTS THROUGH THE REMAINDER OF THE VALID PERIOD.
EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS THURSDAY WITH BREEZY
CONDITIONS THROUGH FRIDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 615 PM THURSDAY...PERSISTENCE THE WORD HERE...CURRENT WIND
AND SEA CONDITIONS REMAIN WITHIN THE CONSTRAINTS OF THE CURRENT
FORECAST. SEE NO CHANGES NEEDED AT THIS TIME. THE NEXT UPDATE MAY
WARRANT THE EXTENSION OF THE SCA OUT FURTHER IN TIME...IF MODEL
CONSENSUS REMAINS UNCHANGED.
PREVIOUS DISCUSSION.............................................
AS OF 230 PM THURSDAY...HIGH PRESSURE PRESSING DOWN FROM THE NORTH
WILL KEEP UP A STEADY NORTHEASTERLY FLOW IN THE PRESENT 15 TO 20
KT RANGE. SEAS WILL WILL NOT STRAY FROM PRESENT 4 TO 7 FT
RANGE...SO EXPECT TO KEEP SMALL CRAFT ADVISORY IN EFFECT THROUGH
THE NEAR TERM.
ADVISORY FLAGS REMAIN FLAPPING ACROSS ALL MARINE ZONES FOR 25 KT
GUSTS AND 4-7 FOOT SEAS. STRONG HIGH PRESSURE NORTH OF THE WATERS
WILL CONTINUE TO PRESS SOUTHWARD. LOWER PRESSURE ACROSS FLORIDA
INTERACTING WITH THE HIGH WILL KEEP THE MSLP GRADIENT TIGHT WITH
BLUSTERY NE-E WINDS EXPECTED THROUGH TONIGHT. E WAVES OF 4-7 FEET
WILL RUN IN WAVE INTERVALS OF 6-8 SECONDS RESULTING IN STEEP-FACED
AND TREACHEROUS WAVES. ISOLATED SHOWERS WILL TRACK FROM EAST TO
WEST AND ONSHORE TODAY BUT NO TSTMS OR WIDESPREAD RESTRICTIONS TO
VISIBILITY ARE ANTICIPATED.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...PERSISTENT NORTHEAST FLOW CONTINUES THROUGH
THE PERIOD. THERE MAY BE A LITTLE VEERING VERY LATE IN THE PERIOD
TO MORE OF A EASTERLY FLOW BUT OVERALL...THE NE FLOW WILL BE THE
STORY. STRONGEST WINDS WILL OCCUR FRIDAY WITH A FEW AREAS ACROSS
THE OUTER WATERS POSSIBLY EXCEEDING 25 KNOTS. FOR NOW THINK THESE
SPEEDS WILL BE LIMITED IN DURATION TO KEEP GALE CONSIDERATION IN
CHECK. SEAS WILL REMAIN RUGGED THROUGH THE PERIOD AND WILL ALMOST
CERTAINLY SEE THE SMALL CRAFT ADVISORY CONTINUE.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...FAIRLY COMPLEX AND ACTIVE WEATHER EXPECTED FOR
MOST OF THE PERIOD ESPECIALLY EARLY ON. A DEEPLY CUTOFF UPPER SYSTEM
WILL APPROACH FROM THE WEST ON SUNDAY WITH A COLD FRONT ALONG ITS
LEADING EDGE. ONSHORE/EASTERLY FLOW WILL GET PINCHED BY THIS
APPROACHING BOUNDARY AS HIGH PRESSURE NOSED INTO THE CAROLINAS TRIES
TO HOLD ITS GROUND. AT SOME POINT THERE SHOULD BE SOME PRETTY SHARP
VEERING AS THE HIGH LOSES GROUND TO THE APPROACHING FRONT...AND THIS
IS PROBABLY THE MOST UNCERTAIN PART OF THE FORECAST. SOUTHERLY FLOW
SHOULD OVERSPREAD BY MONDAY WITH ADDITIONAL VEERING DUE TO THE
CYCLONIC CURVATURE OF THE ISOBARS COMING ACROSS THE CAROLINAS MONDAY
NIGHT INTO TUESDAY. ALL OF THE CHANGING OF THE WIND DIRECTION
THROUGH THE PERIOD SHOULD KEEP WAVE FACES RATHER STEEP AND PERIODS
SHORT MAKING FOR CHOPPY CONDITIONS. WHETHER OR NOT ANY CAUTIONARY
HEADLINES OR EVEN ADVISORIES ARE NEEDED TO TO WAVE HEIGHTS IS VERY
UNCERTAIN BUT WIND SPEEDS WILL REMAIN SHY OF EITHER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH/REK
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
629 PM EDT THU MAY 2 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER NEW ENGLAND THROUGH THE WEEKEND THEN
WEAKEN SOME EARLY NEXT WEEK. LOW PRESSURE EXTENDING UP THE
MISSISSIPPI VALLEY TO LAKE MICHIGAN WILL STAY STATIONARY INTO
SATURDAY THEN SLOWLY MOVE EAST THROUGH THE LOWER TENNESSEE VALLEY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LITTLE CHANGE TO CURRENT FORECAST AT THIS TIME. LATEST HRRR MODEL
INDICATES A BIT OF CONVECTION DEVELOPING LATER TONIGHT OVER THE
EXTREME WEST. HOWEVER...WITH AIR MASS OVER THE REGION BEING SO
DRY...WE MAY JUST ESCAPE WITH A FEW SPRINKLES. OTHERWISE...THE
REST OF THE FORECAST AREA WILL REMAIN DRY AND QUITE PLEASANT TONIGHT.
LAKE BREEZE DROPPED TEMPERATURES INTO THE UPPER 50S ALONG THE
IMMEDIATE LAKESHORE AND LOWER TO MIDDLE 60S A BIT FURTHER INLAND.
EXPECTING LAND BREEZE TO DEVELOP AND BRING AND END TO THE COOLER
TEMPERATURES. WE SHOULD SEE A RISE IN THE TEMPERATURES THIS
EVENING BEFORE FALLING OFF AGAIN. TEMPERATURES ACROSS THE REST OF
THE AREA WILL SEE A GRADUAL DECLINE AFTER SUNSET.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
UPPER LEVEL TROUGH CLOSES OFF OVER THE SOUTHERN PLAINS ON FRIDAY
THEN SLOWLY DRIFTS EASTWARD OVER THE WEEKEND. HIGH CLOUD WILL
CONTINUE TO SPREAD NORTH AROUND THE UPPER LOW AND EXPECT PERIODS OF
SUN AND CLOUD OVER THE NEXT COUPLE DAYS. LOW LEVEL FLOW MAINTAINS AN
EASTERLY WIND COMPONENT BETWEEN HIGH PRESSURE OVER NEW ENGLAND AND
THE LOW TO THE SOUTH. THIS WILL CAUSE LOW LEVELS TO ACTUALLY UNDERGO
SOME DRYING BY SATURDAY AND 12Z MODELS MAINTAIN A DRY FORECAST
THROUGH THE WEEKEND. MODELS HAVE STRUGGLED WITH THE TRACK OF THE LOW
OVER THE LAST COUPLE DAYS BUT HAVE COME INTO FAIRLY GOOD AGREEMENT.
TEMPERATURES ON FRIDAY WILL BE SIMILAR TO TODAY THEN SETTLE BACK
DOWN INTO THE LOWER 70S AS THE AIRMASS COOLS OVER THE WEEKEND.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
IT APPEARS THAT MOST IF NOT ALL OF THE LONG TERM PERIOD WILL BE
DRY. THERE COULD BE A FEW SHOWERS IN THE SOUTH MONDAY AND TUESDAY
AS THE UPPER LOW PASSES TO THE SOUTH OF THE REGION. CHANCES ARE
REALLY SMALL AND NO MORE THAN A HUNDREDTH OR TWO OF RAINFALL IS
EXPECTED EVEN IF SHOWERS DEVELOP. HIGH PRESSURE WILL RETURN
WEDNESDAY AND THURSDAY WITH DRY WEATHER EXPECTED. TEMPERATURES WILL
AVERAGE ABOUT 5 DEGREES ABOVE NORMAL DURING THE PERIOD WITH HIGHS
TUESDAY THROUGH THURSDAY REACHING THE 70S.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
QUIET WEATHER WILL CONTINUE. THERE COULD BE A BRIEF INCREASE IN
CLOUDS IN THE FAR WEST LATE TONIGHT. THE REST OF THE AREA WILL SEE
JUST A FEW HIGH CLOUDS. SE TO E FLOW WILL CONTINUE. A LAKE BREEZE
HAS ALREADY DEVELOPED AT KERI. DO NOT THINK A LAKE BREEZE WILL
REACH KCLE.
.OUTLOOK...NON-VFR CONDITIONS POSSIBLE BY MONDAY.
&&
.MARINE...
A FAIRLY PERSISTENT PATTERN WILL CONTINUE OVER LAKE ERIE INTO THE
WEEKEND. THE RIDGE WILL REMAIN OVER THE REGION AS AN UPPER LEVEL
LOW REMAINS TO THE WEST. A SOUTHEAST FLOW WILL REMAIN OVER THE LAKE
WITH AN ONSHORE FLOW DEVELOPING IN THE AFTERNOON. THE MODELS SHOW
THE UPPER LEVEL LOW DRIFTING SOUTH OF THE OHIO VALLEY FOR THE
BEGINNING OF NEXT WEEK. THIS WILL ALLOW THE WINDS TO SHIFT MORE
FROM THE NORTHEAST AND EVENTUALLY NORTHERLY BY LATE NEXT WEEK. THE
FLOW SHOULD REMAIN FAIRLY LIGHT AND REMAIN 15 KNOTS OR LESS THROUGH
MOST OF THE PERIOD.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...LOMBARDY
SHORT TERM...KEC
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...GARNET
AREA FORECAST DISCUSSION
NWS TULSA OK
1155 PM CDT WED MAY 1 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
VFR CONDITIONS WILL BE BRIEF ACROSS ERN OK TAF SITES...BUT PERSIST INTO
THE OVERNIGHT AT THE REMAINING SITES. ONCE THE STRONG COLD FRONT
SWEEPS ACROSS THE ENTIRE AREA...MVFR AND IFR CIGS ARE EXPECTED BEHIND THE
FRONT ALONG WITH SCATTERED SHOWERS...AND PERHAPS AN ISOLATED
THUNDERSTORM. GUSTY NW WINDS WILL PERSIST ONCE THE FRONT PASSES.
AREAL COVERAGE OF RAIN WILL INCREASE WITH TIME FROM WEST TO
EAST...HOWEVER,,,THE HIGHEST RAINFALL COVERAGE IS EXPECTED TO
REMAIN ACROSS ERN OK FOR MUCH OF THE TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 851 PM CDT WED MAY 1 2013/
DISCUSSION...
STORMS DEVELOPED WEST AND NORTH OF TULSA DURING PEAK HEATING IN AN
ENVIRONMENT THAT MORE CLOSELY RESEMBLES WHAT YOU WOULD SEE IN THE
SUMMER RATHER THAN THE FIRST OF MAY. THEY WERE PULSE IN
NATURE...AND WHAT IS LEFT OF THEM IS MOVING NORTH OVER OSAGE
COUNTY AT THE MOMENT. THE COLD FRONT HAS UNDERCUT THE STORMS...AND
MAY PROVIDE SOME TEMPORARY LIFT TO KEEP THEM GOING.
HOWEVER...SINCE THE MAIN ENERGY SOURCE HAS SET FOR THE NIGHT...I
THINK THESE STORMS WILL SEE THEIR DEMISE SOON. THE LATEST RUN OF
THE HRRR AND THE 18Z NAM BOTH SUGGEST IT WILL BE FAIRLY QUIET
ALONG THE SURGING FRONT TONIGHT. THE POTENT PV ANOMALY OVER
WESTERN CO IS STILL WELL WEST TONIGHT...AND LIFT FROM THIS SYSTEM
WILL NOT OVERSPREAD THE REGION TILL TOMORROW. THE HRRR SHOWS THE
POST-FRONTAL BAND OF PRECIP MOVING INTO NORTHEAST OK AFTER 12Z.
LACY
PREV DISCUSSION... /ISSUED 625 PM CDT WED MAY 1 2013/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
VFR CONDITIONS WILL PREVAIL FOR THE EARLY PORTION OF THE TAF
PERIOD. A STRONG COLD FRONT WILL SWEEP ACROSS THE AREA TONIGHT
WITH MVFR AND IFR CIGS BEHIND THE FRONT. SCATTERED SHOWERS AND
PERHAPS AN ISOLATED THUNDERSTORM WILL ALSO OCCUR BEHIND THE
FRONT...BUT THE CHANCE OF THUNDER IS TOO LOW TO INCLUDE AT THIS
TIME. GUSTY NW WINDS WILL PERSIST ONCE THE FRONT PASSES. AREAL
COVERAGE OF RAIN WILL INCREASE WITH TIME FROM WEST TO
EAST...HOWEVER,,,THE HIGHEST RAINFALL COVERAGE IS EXPECTED TO
REMAIN ACROSS ERN OK FOR MOST OF THE TAF PERIOD.
PREV DISCUSSION... /ISSUED 358 PM CDT WED MAY 1 2013/
DISCUSSION...
FOLKS...ENJOY THE REST OF TODAY BECAUSE ITS ABOUT TO GO SOUTH
IN A BIG HURRY. UNSEASONABLY STRONG COLD FRONT WHICH HAS BEEN
SHOWN IN LAST SEVERAL MODEL RUNS IS MOVING THROUGH WESTERN OK
THIS AFTERNOON WITH TEMPS FALLING IN LOW-MID 40S WITHIN SHORT TIME
OF FROPA. MOISTURE RETURN AHEAD OF THE FRONT HAS BEEN SUPPRESSED
FAIRLY WELL BY SUMMER LIKE LOW ALONG GULF COAST. THIS LOW HAS
MOVED FAR ENOUGH NORTH TO INFLUENCE WESTERN ARKANSAS WITH ISOLATED
AFTERNOON STORMS OVER HIGHER TERRAIN. NOT MUCH ALONG THE FRONT
YET BUT A FEW STORMS HAVE DEVELOPED OVER SW OK.
CAPPED ATMOSPHERE AND UPPER AIR SUPPORT LAGGING WELL BEHIND THE
FRONT WILL KEEP CHANCE OF SEVERE STORMS ALONG THE FRONT MINIMAL
THROUGH THE EVENING...PLUS ANY STORM THAT CAN GET GOING IN THE
WARM AIR WILL BE UNDERCUT QUICK. THE MAIN MESSAGE WITH THIS SYSTEM
IS THE MUCH COLDER TEMPERATURES...AND THE ALMOST UNTHINKABLE
CHANCE OF WINTER PRECIP BY THURSDAY NIGHT AND EARLY FRIDAY OVER
NORTHERN AREAS. MODELS REMAIN DIVERGENT WITH THE STRENGTH AND
TRACK OF UPPER LEVEL LOW...GFS FARTHER SOUTH AND OVERALL SCARIEST
IN TERMS OF SNOW POTENTIAL...NAM COLDEST BUT FASTER. UK/ECMWF ARE
THE MOST REASONABLE LOOKING AT THIS POINT AND HAVE BEEN FOLLOWED...
WITH A NOD TO THE LOCAL WRF FOR TEMP TRENDS ALONG AND WEST OF THE
FRONT TONIGHT.
PRECIP SHOULD BEGIN TO INCREASE LATER THURSDAY AND THU NIGHT AS
THE UPPER SYSTEM MOVES CLOSER...AND THIS AFFORDS US OUR SHOT AT
SNOW. GIVEN THE TIME OF YEAR...IT WILL TAKE A BURST OF HEAVY
SNOWFALL OVER A LONG ENOUGH PERIOD TO ACCUMULATE SNOW AS SFC TEMPS
LIKELY TO REMAIN JUST ABOVE FREEZING. STILL...IT WILL ONLY TAKE A
SMALL AMOUNT TO CAUSE SERIOUS ISSUES IN TERMS OF ACCUMULATING ON
TREES WITH LEAVES. CONFIDENCE NOT HIGH ENOUGH FOR ADVISORY AS A
DEGREE OR TWO WILL MAKE ALL THE DIFFERENCE...BUT A STRONGLY WORDED
SPS WILL BE ISSUED DUE MAINLY TO THE UNPRECEDENTED NATURE OF THIS
EVENT.
OVERALL TREND WILL BE FOR PRECIP TO DIMINISH DURING THE DAY FRIDAY
WITH RECORD LOW MAXES LIKELY AS TEMPS STRUGGLE TO REACH 50 DEGREES
IN AREAS WHERE PRECIP LINGERS LONG ENOUGH. COULD SEE A BIT OF WRAP
AROUND PRECIP MIX WITH SNOW OVER NW ARKANSAS FRIDAY NIGHT.
FREEZING TEMPS POSSIBLE THU NIGHT IN NE OK AND NW AR FRI NIGHT...
FREEZE WATCH ISSUED FOR NE OK THU NIGHT AND ONE MAY END UP BEING
NEEDED FOR NW ARKANSAS FRI NIGHT.
BEYOND THAT A RETURN TO MORE NORMAL SPRING WEATHER SHOULD OCCUR
WITH TEMPS CLOSER TO NORMAL BY EARLY NEXT WEEK. ANOTHER SYSTEM
COULD BRING SHOWERS AND THUNDERSTORMS TUE/WED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 42 43 34 49 / 60 70 90 40
FSM 62 64 38 50 / 20 70 90 40
MLC 47 48 35 51 / 30 60 90 20
BVO 40 41 33 49 / 70 80 90 50
FYV 53 53 35 46 / 20 70 100 50
BYV 54 55 37 44 / 20 70 100 60
MKO 47 48 35 50 / 40 60 100 40
MIO 44 45 34 47 / 60 80 100 60
F10 44 44 34 51 / 40 70 90 30
HHW 54 56 37 54 / 20 50 60 20
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...FREEZE WATCH FROM 1 AM FRIDAY TO 10 AM FRIDAY FOR OKZ054-OKZ055-
OKZ056-OKZ057-OKZ059-OKZ060-OKZ061-OKZ064-OKZ065-OKZ066.
AR...NONE.
&&
$$
AVIATION...23
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
956 AM EDT THU MAY 2 2013
.DISCUSSION...
12Z RAOBS ACROSS THE REGION LOOK QUITE STABLE...AND FORECAST
SOUNDINGS FROM THE RUC INDICATE THAT STABLE CONDITIONS WILL
CONTINUE THROUGH THE DAY. A FEW ISOLATED SHOWERS COULD PRODUCE SOME
TRACE AMOUNTS IN SOUTHERN AREAS WHERE MOISTURE DEPTH IS
GREATEST...BUT WITH A LACK OF LIFT...THERE IS NO COMPELLING REASON
TO CHANGE THE CURRENT DRY FORECAST. TEMPS APPEAR TO BE ON
TRACK...SO NO UPDATE IS PLANNED.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1211 AM CDT THU MAY 2 2013
.DISCUSSION...
LOOK FOR CHALLENGING FLIGHT WEATHER CONDITIONS TO CONTINUE ACROSS
WEST CENTRAL TEXAS FOR THE REMAINDER OF TONIGHT AND MUCH OF
TOMORROW. PLEASE SEE AVIATION BELOW FOR DETAILS.
&&
.AVIATION...
MODELS THIS FORECAST CYCLE CONTINUE TO PRESENT A PICTURE FOR WEST
CENTRAL TEXAS WHICH INCLUDES MVFR CEILINGS AND VERY GUSTY NORTH
SURFACE WINDS FOR MUCH OF THE NEXT 24 HOURS. THE LATEST RUC AND
NAM CONTINUE THUNDERSTORMS ACROSS OUR HEARTLAND AND NORTHWEST
HILL COUNTRY COUNTIES FOR A FEW MORE HOURS. THEN...DRIZZLE OR
LIGHT SHOWERS WILL BE THE PRECIPITATION PRODUCERS OVER WEST
CENTRAL TEXAS UNTIL TOMORROW EVENING. THE UPPER-LEVEL THROUGH WILL
CONTINUE TO SLIDE OVER TEXAS INTO TOMORROW. AT THE SURFACE...COLD
AIR WILL CONTINUE TO MOVE INTO WEST CENTRAL TEXAS BEHIND THE
FRONT. SO...GUSTY NORTH SURFACE WINDS TOMORROW...ESPECIALLY DURING
THE AFTERNOON HOURS...CONTINUE TO LOOK LIKELY. WITH SOME
DISAGREEMENT AMONG THE MODELS...MY CONFIDENCE REGRADING WHEN VFR
CONDITIONS WILL RETURN TO WEST CENTRAL TEXAS IS NOT VERY HIGH.
THUS...I DECIDED TO CONTINUE MVFR CEILINGS AT ALL FIVE TERMINALS
UNTIL 18Z...WITH ONLY A PROB30 GROUP FROM 18Z UNTIL 00Z.
HUBER
&&
.PREV DISCUSSION... /ISSUED 1114 PM CDT WED MAY 1 2013/
UPDATE...
LATEST RADAR DATA INDICATE SHOWERS AND THUNDERSTORMS ARE SLOWLY
CLEARING OUR COUNTIES...AS THEY MOVE FARTHER SOUTHEAST. AFTER
COORDINATION WITH SPC...I HAVE CANCELED SEVERE THUNDERSTORM WATCH
146 FOR A FEW MORE OF OUR COUNTIES. I WILL ALLOW THE REMAINING
COUNTIES TO CONTINUE IN THIS WATCH UNTIL IT EXPIRES AT MIDNIGHT.
ALSO...I REMOVED THUNDERSTORMS FROM THE FORECAST FOR THE REMAINDER
OF TONIGHT FOR THOSE COUNTIES I REMOVED FROM THIS WATCH. RECENT
TEXT PRODUCTS REFLECT MY GRID UPDATES.
HUBER
PREV DISCUSSION... /ISSUED 1022 PM CDT WED MAY 1 2013/
UPDATE...
AFTER COORDINATION WITH SPC...I CLEARED SOME OF OUR NORTHWESTERN
COUNTIES FROM SEVERE THUNDERSTORM WATCH 146. THUNDERSTORMS ARE
CONTINUING TO MOVE SLOWLY SOUTHEAST WITH THE LEADING EDGE OF THE
COLD FRONT. TEMPERATURES AROUND 55 HAVE ALREADY MOVED INTO OUR
NORTHERN BIG COUNTRY COUNTIES...WHERE NORTH SURFACE WINDS AROUND
20 MPH DOMINATE. ALSO...I REMOVED THUNDERSTORMS FROM THOSE
COUNTIES I CLEARED FROM THE WATCH. RECENT TEXT PRODUCTS REFLECT
THESE GRID CHANGES.
HUBER
PREV DISCUSSION... /ISSUED 640 PM CDT WED MAY 1 2013/
DISCUSSION...
LOOK FOR VERY CHALLENGING FLIGHT WEATHER CONDITIONS ACROSS WEST
CENTRAL TEXAS FOR THE NEXT 24 HOURS. AVIATION BELOW HAS DETAILS.
AVIATION...
A STRONG COLD FRONT WILL PUSH SOUTH ACROSS WEST CENTRAL TEXAS
TONIGHT AND PRODUCE THUNDERSTORMS...ALONG WITH MVFR
CEILINGS...REDUCED VISIBILITY...A GUSTY NORTH WINDS. THE LATEST
RUC INDICATES THE LEADING EDGE OF THIS COLD FRONT WILL PUSH SOUTH
OF OUR INTERSTATE 10 CORRIDOR AROUND 08Z TONIGHT.
MEANWHILE...THUNDERSTORMS HAVE DEVELOPED...AND ARE
DEVELOPING...ALONG THE LEADING EDGE OF THIS FRONTAL BOUNDARY. SOME
OF THE THUNDERSTORMS MAY PRODUCE DAMAGING WINDS AND LARGE HAIL.
BEHIND THE FRONT...I EXPECT OVERCAST MVFR CEILINGS AND LIGHT RAIN
TO DOMINATE WEST CENTRAL TEXAS FOR THE REMAINDER OF THIS FORECAST
PERIOD. ALSO...WATCH FOR VERY STRONG WINDS TOMORROW...ESPECIALLY
DURING THE AFTERNOON...AS COLD AIR MOVES INTO TEXAS FROM THE NORTH.
HUBER
PREV DISCUSSION... /ISSUED 513 PM CDT WED MAY 1 2013/
UPDATE...
AFTER COORDINATION WITH THE STORM PREDICTION CENTER...WE HAVE
ISSUED SEVERE THUNDERSTORM WATCH 146 WHICH WILL REMAIN IN EFFECT
UNTIL MIDNIGHT TONIGHT. I HAVE SENT A ZONE UPDATE TO INCLUDE THE
WATCH HEADLINE. AT THIS TIME...WE ARE THINKING THE MAIN THREAT
WILL BE DAMAGING WINDS.
HUBER
PREV DISCUSSION... /ISSUED 342 PM CDT WED MAY 1 2013/
SHORT TERM...
THE COLD FRONT...WHICH IS MORE OF A WIND SHIFT IN SOUTHERN
AREAS...HAS MADE IT INTO THE LOWER TRANS PECOS AREA...AND INTO OUR
EXTREME WESTERN COUNTIES. A WEAK SFC MESOLOW OR HEAT LOW CAN BE SEEN
IN RADAR DATA IN THE NORTHERN CONCHO VALLEY. TEMPERATURES HAVE
SOARED INTO THE UPPER 90S ACROSS THE CONCHO VALLEY WITH UPPER 80S TO
LOWER 90S ACROSS THE REST OF THE FORECAST AREA.
THERE IS STILL THE POSSIBILITY OF SOME ISOLATED STORMS DEVELOPING
THIS EVENING ACROSS THE SOUTHERN CONCHO VALLEY/NORTHERN EDWARDS
PLATEAU. WHILE SHEAR ISN/T THAT STRONG ACROSS THE AREA...WITH CAPE
VALUES JUST EAST OF THESE AREAS NOW EXCEEDING 3000 J/KG AT THE
SURFACE...ANY STORMS THAT DO DEVELOP WOULD QUICKLY BECOME STRONG TO
SEVERE WITH LARGE HAIL AND DAMAGING WINDS BEING THE MAIN HAZARDS.
THE MAIN CAVEATS WITH THUNDERSTORMS IN OUR AREA IS THE LACK OF
STRONG UPPER LEVEL SUPPORT OR A WELL DEFINED SFC FOCUS.
OVERNIGHT...THE COLD FRONT WILL SURGE SOUTHWARD...AND ADDITIONAL
ELEVATED CONVECTION BEHIND THE FRONT IS POSSIBLE. WITH INSTABILITY
DECREASING OVERNIGHT...EXPECT LESS OF A CHANCE FOR SEVERE
THUNDERSTORMS...BUT THERE COULD STILL BE THUNDERSTORMS THAT PRODUCE
SOME SMALL HAIL AND GUSTY WINDS.
MUCH COLDER AIR WILL MOVE INTO THE AREA BEHIND THE COLD FRONT FOR
TOMORROW...AND WINDS WILL ALSO BE QUITE STRONG...LIKELY 20 TO 35 MPH
THROUGHOUT THE AREA WITH GUSTS APPROACHING 45 MPH AT TIMES. THIS
WILL BE DUE TO STRONG PRESSURE RISES ASSOCIATED WITH A 1040+ MB
SURFACE HIGH MOVING INTO THE AREA. THURSDAY WILL BE A COLD...
CLOUDY...WINDY DAY WITH SOME SCATTERED SHOWERS AT TIMES. A WIND
ADVISORY WILL BE IN EFFECT FROM EARLY TOMORROW MORNING THROUGH
TOMORROW EVENING.
LONG TERM...
THURSDAY NIGHT THROUGH FRIDAY NIGHT...COLD TEMPERATURES ARE EXPECTED
THURSDAY NIGHT AS STRONG SURFACE HIGH SETTLES IN ALONG WITH GOOD LOW
LEVEL COLD AIR ADVECTION. LOWS BY FRIDAY MORNING WILL BE IN THE 30S.
A FEW UPPER 20S ARE POSSIBLE IF WINDS CAN DECOUPLE...THAT MAY BE A
PROBLEM DUE TO THE WINDS STAYING UP. THE NAM MOS GUIDANCE HAS A LOW
OF 23 AT JUNCTION FRIDAY MORNING WHICH IS PRETTY AMAZING FOR MAY
3. WILL GO WITH A FREEZE WATCH FOR LATE THURSDAY NIGHT AND FRIDAY
MORNING ACROSS ALL OF WEST CENTRAL TEXAS. TEMPERATURES WILL
MODERATE SOME FRIDAY WITH HIGHS IN THE 60S. ANOTHER COLD NIGHT FOR
FRIDAY NIGHT WITH LOWS MAINLY IN THE 30S. FREEZING TEMPERATURES
ARE POSSIBLE SATURDAY MORNING MAINLY ACROSS THE HEARTLAND AND
NORTHWEST HILL COUNTRY AS WINDS WILL HAVE A BETTER CHANCE TO
DECOUPLE SETTING UP IDEAL RADIATIONAL COOLING. SEE CLIMATE
INFORMATION BELOW FOR SPECIFICS.
SATURDAY THROUGH WEDNESDAY...EXPECT A WARMING TREND THROUGH THE
PERIOD...WITH HIGHS IN THE 80S MONDAY THROUGH WEDNESDAY. THE GFS
MODEL IS INDICATING AN UPPER LEVEL TROF UNDERCUTTING A RIDGE OVER
THE PACIFIC NORTHWEST. SOME OF THIS ENERGY MAY MOVE INTO THE
SOUTHERN PLAINS AS A DRYLINE DEVELOPS TO OUR WEST BY MIDDLE OF NEXT
WEEK. FORECAST CONFIDENCE IS LOW AT THIS TIME AND ALL OF WEST CENTRAL
TEXAS IS CURRENTLY IN SEVERE OR GREATER DROUGHT CONDITIONS. KEEPING
THE FORECAST DRY FOR NOW.
CLIMATE...
RECORD LOWS POSSIBLE FRIDAY AND SATURDAY...
ABILENE MAY 3 - FORECAST LOW 34 (RECORD LOW 37 IN 2011)
MAY 4 - FORECAST LOW 37 (RECORD LOW 33 IN 1907)
ALL TIME LOW TEMPERATURE FOR MAY - 33
SAN ANGELO MAY 3 - FORECAST LOW 32 (RECORD LOW 37 IN 2011)
MAY 4 - FORECAST LOW 36 (RECORD LOW 39 IN 1945)
ALL TIME RECORD LOW FOR MAY - 35
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 39 46 34 62 37 / 50 30 5 0 0
SAN ANGELO 45 48 32 66 36 / 50 30 5 0 0
JUNCTION 51 53 30 68 33 / 50 40 5 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY MORNING FOR
THE FOLLOWING ZONES: BROWN...CALLAHAN...COKE...COLEMAN...
CONCHO...CROCKETT...FISHER...HASKELL...IRION...JONES...KIMBLE...
MASON...MCCULLOCH...MENARD...NOLAN...RUNNELS...SAN SABA...
SCHLEICHER...SHACKELFORD...STERLING...SUTTON...TAYLOR...
THROCKMORTON...TOM GREEN.
WIND ADVISORY FROM 4 AM TO 7 PM CDT THURSDAY FOR THE FOLLOWING
ZONES: BROWN...CALLAHAN...COKE...COLEMAN...CONCHO...CROCKETT...
FISHER...HASKELL...IRION...JONES...KIMBLE...MASON...MCCULLOCH...
MENARD...NOLAN...RUNNELS...SAN SABA...SCHLEICHER...SHACKELFORD...
STERLING...SUTTON...TAYLOR...THROCKMORTON...TOM GREEN.
&&
$$
HUBER
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1207 AM CDT THU MAY 2 2013
.AVIATION...
BKN-OVC MVFR CLOUD DECKS HAVE DEVELOPED ACROSS KLBB AND KCDS
TONIGHT...IN ADDITION TO MVFR FOG HAVE DEVELOPED AT KCDS. COMPUTER
MODELS CONTINUE TO HINT AT LIGHT -RA DEVELOPING INITIALLY AT KCDS
/WHICH IT HAS/...WITH PRECIP EXPANDING SOUTH AND WEST TO KLBB
THROUGHOUT THE NIGHT. FURTHERMORE...AS TEMPS COOL ALOFT AND AT THE
SFC...THE CHANCE FOR WINTRY PRECIP WILL BE POSSIBLE...ESPECIALLY
AS A BROAD UA TROUGH SWINGS ACROSS THE HIGH AND CENTRAL
PLAINS...WITH ITS SOUTHERN PERIPHERY HAVING THE POTENTIAL TO BRUSH
ACROSS THE SOUTHERN PLAINS. THUS...HAVE ADDED A TEMPO GROUP FOR -RAPL
AND -RASNPL AT KCDS AND KLBB RESPECTIVELY. RATHER BREEZY NORTH
WINDS WILL PERSIST TONIGHT WITH THE POTENTIAL FOR AWW CRITERIA
OCCURRING AT KLBB...ALTHOUGH CONFIDENCE IS NOT HIGH ENOUGH FOR AN
AWW ISSUANCE ATTM /WILL NEED TO KEEP A CLOSE EYE ON THE WIND
SPEEDS/. THEREAFTER...CLEARING SKIES FROM WEST TO EAST WILL OCCUR
BY MID-MORNING TOMORROW...WITH WIND SPEEDS EXPECTED TO DECLINE.
&&
.PREV DISCUSSION... /ISSUED 1024 PM CDT WED MAY 1 2013/
UPDATE...
STRONGER SURFACE PRESSURE GRADIENT GRADUALLY DEVELOPING AND WE ARE
SEEING MORE SITES REACHING WELL INTO WIND ADVISORY LEVELS VIA THE
WEST TEXAS MESONET. STRONGER WINDS ALSO DEVELOPING OVER CASTRO
COUNTY JUST SHY OF HIGH WIND WARNING LEVELS. WE OPTED TO EXPAND
THE HIGH WIND WARNING INTO CASTRO COUNTY AND THE WIND ADVISORY
ACROSS THE ROLLING PLAINS. THE LATEST WRF/NAM AND HRRR RUNS ARE
CONSISTENT BREAKING LIGHT PRECIPITATION OUT ACROSS MAINLY NORTHERN
ROLLING PLAINS BEFORE MIDNIGHT...THEN EXPANDING BACK OVER MUCH OF
OUR AREA EARLY THURSDAY UNTIL ABOUT MID THURSDAY MORNING WITH
COMBINATION OF ISENTROPIC UPGLIDE...SLOPED FRONTOGENETIC FORCING...
AND DEEPER SYNOPTIC FORCING WITH UPPER TROUGH SWINGING OVERHEAD.
MOISTURE REMAINS LIMITED MOSTLY AROUND 650-700 MB OR LOWER SO
PRECIPITATION TOTALS EXPECTED TO BE LIGHT...TRACE TO 10 HUNDREDTHS
OF AN INCH FOR THE MOST PART. WE INCREASED PRECIPITATION CHANCES
OVER MOST OF THE AREA LATER TONIGHT AND EARLY THURSDAY. PHASE
CONTINUES TO FAVOR A SLEET/LIQUID MIX BECOMING A SLEET/FROZEN/LIQUID
MIX ON THE CAP-ROCK EARLY THURSDAY. MOST AREAS OVER THE ROLLING
PLAINS SHOULD REMAIN LIQUID...WITH EXCEPTION OF NORTHERN ROLLING
PLAINS WHICH ALSO MAY SEE SLEET MIXING IN EARLY THURSDAY. WITH THE
LIGHT AMOUNTS WE HAVE OPTED FOR NO WINTER WEATHER HIGH-LITES...
ALTHOUGH A BAND OR TWO OF MODERATE INTENSITY PRECIPITATION WITH
TEMPERATURES HOVERING NEAR FREEZING EARLY THURSDAY HAS SOME
POTENTIAL FOR LIGHT ACCUMULATIONS OVER THE NORTH-CENTRAL TO
NORTHEAST PART OF OUR AREA. UPDATE HAS BEEN ISSUED. RMCQUEEN
PREV DISCUSSION... /ISSUED 332 PM CDT WED MAY 1 2013/
SHORT TERM...
A VERY DYNAMIC LATE SPRING STORM TO BRING STRONG NORTH WINDS AND
CHANCE FOR GENERALLY LIGHT RAIN AND EVEN POSSIBILITY OF LIGHT WINTRY
PRECIPITATION TO THE AREA. THE PARENT UPPER LOW/TROUGH CONTINUES TO
STRENGTHEN OVER THE INTER-MOUNTAIN WEST WHILE AT THE SFC THE STRONG
COLD FRONT HAS ALREADY CLEARED THE FCST AREA. MAIN THREAT LOOKING TO
BE WINDS AS VERY STRONG PRESSURE RISES ARE EXPECTED TO MOVE SWD DOWN
THE SRN HIGH PLAINS WITH A BARRIER JET LIKELY DEVELOPING JUST ON THE
LEE OF THE MOUNTAINS OF CNTL NM. COMBINATION WILL MEAN AT LEAST WIND
ADVISORY LEVEL WINDS FOR ALL OF THE AREA ON THE CAPROCK WITH GOOD
POTENTIAL FOR WARNING CRITERIA TO BE MET ACROSS THE NW /SPECIFICALLY
PARMER AND BAILEY COUNTIES/.
AS FOR PRECIP...HAVE BEEN CONCERNED WITH RECENT MODEL BIASES TOWARD
BEING TOO WET IN THE POST-FRONTAL AIR MASS AS THEY HAVE BEEN WITH
THE LAST SEVERAL OF THESE EVENTS. IN ESSENCE...IT APPEARS THAT THE
NAM IN PARTICULAR CONVERTS TOO MUCH OF THE LIFT FROM FRONTOGENETICAL
AND ISENTROPIC MECHANISMS TO PRECIPITATION POSSIBLY FROM TOO
AGGRESSIVELY MOISTENING THE DEEPENING COLD LAYER. INSTEAD RESULT HAS
TOO OFTEN BEEN ONLY LOW CLOUDS HIGHER THAN PROGGED AS STRONG COLD
AND DRY ADVECTION WORKS IN IN THE NEAR-SFC LAYER. IT APPEARS THAT
THIS EVENT MAY WORK SIMILARLY. EXCEPTION TODAY MAY BE THE STRENGTH
OF SRN EXTENT OF THE UPPER TROUGH TO THE WEST. Q-VECTOR PROGS
SUGGEST THE TAIL END OF THE LARGE SCALE ASCENT MAY BE FAR ENOUGH
SOUTH TO BRING AN ADDITIONAL PRECIPITATION GENERATION MECHANISM INTO
PLAY LATE TONIGHT THEN BLEEDING OVER PAST 12Z THURSDAY. IT DOES NOT
LOOK LIKE THE FORMER MECHANISMS WILL TEMPORALLY OVERLAP THE LATTER
ONE...BUT IT DOES OFFER AN ADDITIONAL MEANS BY WHICH SOME LIGHT
PRECIP MAY BE GENERATED. OVERALL...GIVEN SKEPTICISM IN RELATION TO
NAM BIASES IN PARTICULAR...WILL FAVOR THE LOWER POPS OF MAVMOS. THAT
MEANS A SMALL REDUCTION IN FCST POPS FOR TONIGHT INTO THURSDAY
MORNING. PROBLEMS PERSIST REGARDING PRECIP PHASE AS WELL. MODEL
SOUNDINGS SHOW POTENTIAL PRECIP GENERATION ZONE ALOFT BEING IN AN
AREA OF RELATIVE WARMTH WITH POTENTIAL FOR SUPERCOOLED DROPS TO FALL
THROUGH THE COLD AIR MASS AT AND JUST ABOVE THE SFC. THIS WOULD TEND
TO FAVOR DRIZZLE IF DRY SUB-CLOUD AIR DOES NOT WIN OUT. SITUATION
COULD CHANGE WITH LARGER SCALE ASCENT FROM THE UPPER TROUGH AND
POTENTIAL FOR IT TO COOL TEMPS ALOFT. THAT COULD LEAD TO SOME SNOW
MAKING INTO WHAT MAY OR MAY NOT BE A MID LEVEL WARM ZONE AT THAT
TIME. SFC TEMPS WOULD FAVOR SNOW OR SLEET IN THIS REGIME MOST LIKELY
ONLY ACROSS THE NWRN AND NCNTL ZONES LATE TONIGHT AND EARLY
THURSDAY. THUS...HAVE PULLED BACK THE WINTRY PRECIP MENTION A BIT
FROM PREVIOUS FCSTS.
FINAL ISSUE FOR TONIGHT IS POTENTIAL FOR A LIGHT FREEZE. THAT SEEMS
MOST LIKELY IN THOSE NWRN AND NCNTL ZONES JUST MENTIONED...AND
WILL ISSUE A FREEZE WARNING FOR THOSE AREAS...ALTHOUGH BETTER
CHANCE FOR A FREEZE OR EVEN HARD FREEZE COMES 24 HOURS LATER.
TEMPS TO BE SLOW TO RISE THURSDAY UNTIL SOME CLEARING CAN BEGIN
TO WORK IN FROM THE WEST DURING THE AFTN. FCST TEMPS WILL BE JUST
BELOW MOS NUMBERS FOR MUCH OF THE AREA.
LONG TERM...
ONE MORE LATE SEASON FREEZE LOOKS TO OCCUR FOR THE SOUTH
PLAINS...ROLLING PLAINS...AND EXTREME SOUTHERN TEXAS PANHANDLE
THURSDAY NIGHT INTO FRIDAY MORNING. AN UNSEASONABLY COLD AIRMASS
WILL BE LOCKED IN ACROSS THE AREA AS SURFACE RIDGING...LIGHT
WINDS...AND CLEAR SKIES PROMOTE STRONG RADIATIONAL COOLING.
FORECASTING BOTH LUBBOCK AND CHILDRESS TO SET DAILY RECORD LOW
TEMPERATURES OF 29 AND 31 RESPECTIVELY (RECORDS ARE 30 AND 34). WILL
KEEP PREVIOUSLY ISSUED FREEZE WATCH IN EFFECT FOR THE ENTIRE
FORECAST AREA.
TEMPERATURES WILL BEGIN WARMING FRIDAY AS WARM AIR PUMPS INTO THE
REGION ALOFT ALONG WITH DOWNSLOPING WINDS. READINGS WILL REBOUND
BACK INTO THE 60S FRIDAY...FOLLOWED BY 60S AND 70S FOR THE
WEEKEND...STILL BELOW NORMAL VALUES OF AROUND 80 FOR THIS TIME OF
YEAR. OVERNIGHT LOWS WILL REMAIN ABOVE FREEZING BEGINNING FRIDAY
NIGHT THROUGH THE REMAINDER OF THE EXTENDED...WITH THE ONE EXCEPTION
PERHAPS BEING FRIDAY NIGHT ACROSS THE EXTREME SOUTHWEST PANHANDLE
AND ADJACENT PORTIONS OF THE SOUTH PLAINS. UPPER LEVEL RIDGING WILL
BUILD IN THROUGHOUT THE WEEKEND RAISING HEIGHTS AND AIDING IN THIS
WARMING TREND...BUT A DISTURBANCE LOOKS TO ATTEMPT TO BREAK DOWN
THIS FEATURE BY LATE WEEKEND OR EARLY NEXT WEEK. MOISTURE WILL TRY
TO MAKE A RETURN...BUT NOWHERE NEAR ENOUGH TO WARRANT POPS AT THIS
TIME.
WILL HAVE TO CONTINUE MONITORING THE EVOLUTION OF AN UPPER LOW
ENTERING THE WESTERN COAST OF THE COUNTRY HEADING INTO THE TUESDAY
TIME-FRAME AND BEYOND. THE CURRENT RUN OF THE ECMWF HAS A PROGRESSIVE
SYSTEM MOVING TOWARD THE PLAINS AND DRAWING UP SOME MOISTURE FROM
THE SOUTH...WHILE THE LATEST GFS ESTABLISHES AN OMEGA BLOCKING
PATTERN NEAR THE HEART OF THE COUNTRY...THUS KEEPING THIS SYSTEM
CONFINED WEST OF THE ROCKIES. MUCH REFINEMENT TO COME IN SUBSEQUENT
FORECASTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 30 45 24 62 32 / 20 20 0 0 0
TULIA 31 44 26 61 34 / 50 40 0 0 0
PLAINVIEW 33 45 26 62 35 / 50 40 0 0 0
LEVELLAND 34 47 26 66 36 / 40 30 0 0 0
LUBBOCK 35 46 29 66 36 / 50 40 0 0 0
DENVER CITY 35 50 29 65 38 / 30 30 0 0 0
BROWNFIELD 35 48 29 66 38 / 40 30 0 0 0
CHILDRESS 37 47 31 62 38 / 60 60 0 0 0
SPUR 37 47 30 65 37 / 60 60 0 0 0
ASPERMONT 40 46 31 65 39 / 60 60 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
THE FOLLOWING ZONES: TXZ021>044.
WIND ADVISORY UNTIL 6 AM CDT THURSDAY FOR THE FOLLOWING ZONES:
TXZ023>026-028>044.
FREEZE WARNING FROM 4 AM TO 9 AM CDT THURSDAY FOR THE FOLLOWING
ZONES: TXZ021>023-027-028.
HIGH WIND WARNING UNTIL 6 AM CDT THURSDAY FOR THE FOLLOWING
ZONES: TXZ021-022-027.
&&
$$
29
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1142 PM CDT WED MAY 1 2013
.AVIATION...
PROBLEMATIC TAF FORECAST OVER THE NEXT 24-30 HOURS WITH TIMING AND
CATEGORY OF LOW CLOUDS AND THE TIMING OF THE FRONT AND PRECIP
CHANCES. ALL CONVECTION HAS STAYED WEST OF TAF SITES AND DO NOT
ANTICIPATE ANY IMPACTS FROM PRECIPITATION IN THE SHORT-TERM. COLD
FRONT HAS REACHED BOWIE...GRAHAM AND BRECKENRIDGE AND LATEST
TIMING BRINGS THE FRONT THROUGH THE METRO AROUND 9-11Z. WINDS ARE
CURRENTLY EAST AND SHOULD BACK A LITTLE TO THE NORTHEAST AND THEN
NORTHWEST WITH THE PASSAGE OF THE COLD FRONT. THIS IS EXPECTED TO
OCCUR AT WACO AN HOUR OR TWO LATER THAN DFW. LAMP AND MET
GUIDANCE ARE PESSIMISTIC WITH THE CIGS BEHIND THE FRONT AND QUICKLY
DROP CIGS INTO LOW MVFR OR IFR AFTER FROPA. CURRENT SURFACE OBS AND
HIGH-RES GUIDANCE FROM THE RAP AND WRF...INDICATE THIS IS NOT
ONGOING AND WILL STEER AWAY FROM THIS SOLUTION. WILL SHOW CIGS
GOING TO BKN025 AFTER FROPA AND THEN OVC010 AT 11Z. KEPT THE
FORECAST MVFR AND NOT IFR AS FORECAST SOUNDINGS FROM BOTH THE
RAP...WRF...AND NAM INDICATE THIS. THE RAW OUTPUT FROM THE NAM
HAS CLOUD BASES AT 1000-1200 FEET ALTHOUGH THE MOS IS FORECASTING
IFR. ANOTHER FACTOR AGAINST IFR WILL BE WIND SPEEDS. SPEEDS AROUND
DAYBREAK ARE EXPECTED TO INCREASE TO 19 KNOTS AND THEN CONTINUE TO
INCREASE TO 24 KNOTS WITH 34+ KNOT GUSTS. PREVIOUS TAF HAD VCSH
FROM FROPA THROUGH 00Z...BUT DO NOT THINK SHOWERS COVERAGE WILL BE
HIGH ENOUGH INITIALLY FOR A MENTION. THINK COVERAGE SHOULD
INCREASE TOMORROW AFTERNOON ONCE THE UPPER SUPPORT WILL ARRIVE AND
HAVE VCSH FROM 16Z UNTIL 00Z. WIND SPEEDS ARE EXPECTED TO SLOWLY
DECREASE TOMORROW NIGHT BUT WILL STILL REMAIN ABOVE 10 KNOTS WITH
CLEARING SKIES OVERNIGHT. THIS FORECAST WILL LIKELY CALL FOR
AMENDMENTS AND UPDATES WITH LATER TAF ISSUANCES.
HAMPSHIRE
&&
.UPDATE...
FINAL UPDATE REGARDING OUR WATCH FOR OUR FAR SOUTHWEST COUNTIES.
THE ATMOSPHERE IS CONTINUING TO STABILIZE EAST OF THE STORM
CLUSTER WEST OF GOLDTHWAITE. CANNOT RULE OUT A STRONG STORM MAKING
IT INTO LAMPASAS OR MILLS COUNTIES BUT SEVERE STORMS ARE NOT
EXPECTED ANYMORE. HAMILTON...MILLS...AND LAMPASAS COUNTIES HAVE
ALL BEEN REMOVED FROM THE WATCH WITH NO COUNTIES IN OUR CWA
REMAINING IN THE WATCH.
OVERNIGHT...AFOREMENTIONED STABILIZATION FROM THE UPPER LOW CLOSE
BY TO THE EAST SHOULD KEEP THE COLD FRONTAL PASSAGE RELATIVELY
INACTIVE AS IT MOVES THRU NORTH AND CENTRAL TEXAS BETWEEN MIDNIGHT
AND NOON THURSDAY. HAVE LEFT SLIGHT CHANCES FOR A FEW SHOWERS AND
MAYBE A THUNDERSTORM ACROSS BELL AND LAMPASAS COUNTIES. WIND
ADVISORY THURSDAY AND THE FREEZE WARNING ACROSS THE NORTHWEST
COUNTIES THURSDAY NIGHT STILL LOOK GOOD.
05/
&&
.PREV DISCUSSION... /ISSUED 310 PM CDT WED MAY 1 2013/
THE COLD FRONT HAS MOVED THROUGH TEXAS PANHANDLE AS I WRITE
THIS...AND IT CONTINUES TO MOVE SOUTHEAST. WINDS WILL LIKELY
SWITCH NORTHEAST AHEAD OF THE COLD FRONT AS THE LOW LEVEL FLOW
RESPONDS TO THE VERTICALLY STACKED SURFACE/UPPER LOW CURRENTLY ON
THE MS/LA BORDER. IT WILL BE HARD TO MISS THE FRONT THOUGH...WITH
A RAPID INCREASE IN WIND SPEED AND DROP IN TEMPERATURE AS THE
FRONT PASSES.
SUBSIDENCE HAS CREATED A STRONG CAP OVER MUCH OF NORTH
TEXAS...BUT IT IS WEAKER IN THE WESTERN COUNTIES. AS THE FRONT
MOVES SOUTHEAST...CONVECTION IS EXPECTED TO INITIATE SOMEWHERE
NEAR THE WICHITA FALLS AREA AND MOVE SOUTHWARD AS A MULTI-
CELLULAR COMPLEX. HAIL AND DAMAGING WINDS REMAIN THE MAIN SEVERE
THREATS IN THE WESTERN ZONES TONIGHT THROUGH THE EARLY MORNING
HOURS THURSDAY.
THE REST OF NORTH TEXAS WILL CERTAINLY SEE THE EFFECTS OF THE
REMARKABLY COLD AIR...BUT RAINFALL AMOUNTS WILL BE LOW. THIS IS
DUE TO THE LOUISIANA SYSTEM BLOCKING GULF MOISTURE FROM SURGING
INTO NORTH TEXAS AHEAD OF THE SYSTEM...AND THE LACK OF INSTABILITY
OVER MUCH OF THE AREA. EXCEPT IN WESTERN ZONES...PRECIP SHOULD BE
PREDOMINANTLY SHOWERS INSTEAD OF THUNDERSTORMS ALTHOUGH ISOLATED
THUNDER MAY BE HEARD THROUGH THURSDAY MORNING. PRECIP SHOULD BE IN
THE FORM OF ELEVATED SHOWERS FROM SUNRISE THURSDAY THROUGH FRIDAY
MORNING WHEN THE SYSTEM SHOULD EXIT THE AREA TO THE EAST.
WE HAVE ISSUED A WIND ADVISORY FOR ALL OF NORTH TEXAS...EXPECTING
NORTHWEST WINDS 25 TO 30 MPH WITH GUSTS OCCASIONALLY AS HIGH AS 40
MPH THURSDAY AFTERNOON. WINDS WILL MODERATE OVERNIGHT AND SHOULD
BE FAIRLY LIGHT BY FRIDAY MORNING. GIVEN THE COLD AIR...WIND
CHILLS WILL DROP INTO THE 20S IN SOME AREAS...AND WIDESPREAD
CHILLS INTO THE LOW 30S ARE EXPECTED. CLOUDS WILL ALSO BE THINNING
FROM WEST TO EAST EARLY FRIDAY AND WE HAVE ALSO ISSUED A FREEZE WATCH
FOR FRIDAY MORNING ALONG AND NORTHWEST OF A LINE FROM EASTLAND TO
GAINESVILLE...EXPECTING LOW TEMPERATURES TO DIP INTO THE LOW 30S
IN THOSE AREAS.
DRY COOL AIR AND CLEAR SKIES PLUS LIGHT WINDS WILL CREATE THE
OPPORTUNITY FOR COLD MORNINGS THROUGH SUNDAY...AND BOTH DFW AND
WACO WILL FLIRT WITH RECORD LOWS THROUGH THE WEEKEND. THE WEEKEND
IS STILL EXPECTED TO BE QUITE PLEASANT...WITH HIGHS NEAR 70 BOTH
DAYS. 84
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 50 50 37 62 43 / 20 40 20 5 0
WACO, TX 53 56 37 64 40 / 20 40 20 5 0
PARIS, TX 57 59 38 60 39 / 20 40 20 5 0
DENTON, TX 47 52 34 61 39 / 20 40 20 5 0
MCKINNEY, TX 51 54 35 62 39 / 20 40 20 5 0
DALLAS, TX 52 55 37 64 43 / 20 40 20 5 0
TERRELL, TX 59 59 37 63 38 / 20 40 20 5 0
CORSICANA, TX 59 59 38 63 40 / 20 40 20 5 0
TEMPLE, TX 53 57 37 64 41 / 30 40 20 5 0
MINERAL WELLS, TX 43 49 33 63 38 / 20 40 20 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 1 PM TO 9 PM CDT THURSDAY FOR TXZ091>095-
100>107-115>123-129>135-141>148-156>162-174-175.
FREEZE WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY MORNING FOR
TXZ091-092-100>102-115>117-129.
&&
$$
85/85
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
943 PM EDT FRI MAY 3 2013
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL PERSIST OFF THE MID-ATLANTIC COAST
INTO THE WEEKEND...KEEPING A COOL...MARITIME...EAST FLOW ACROSS
THE REGION. A DEEP UPPER LOW WILL MOVE VERY SLOWLY FROM THE
TENNESSEE VALLEY LATE IN THE WEEKEND TO ALONG THE NORTH
CAROLINA OR SOUTHEAST VIRGINIA COAST BY THE MID OR LATE PART OF
NEXT WEEK. AN EXTENDED PERIOD OF LIGHT TO MODERATE
RAIN...OCCASIONALLY HEAVY...CAN BE EXPECTED ALONG WITH A
CONTINUATION OF COOL TEMPERATURES ACROSS THE REGION AS A RESULT.
&&
.NEAR TERM /THROUGH SATURDAY/...
.AS OF 930PM...
SURGE OF SC MOVED ACROSS THE AREA FROM THE EAST...AND LIKE THE
WAY THE LATEST RUC HAS CAPTURED THAT FEATURE SO WILL LEAN ON THAT
MODEL FOR THE NEAR TERM SKY CONDITION. WITH THAT IN MIND...EXPECTING
THE INITIAL SC TO MOVE WEST WITH ANOTHER SURGE OF MOISTURE OVERNIGHT
COMBINING WITH DIURNAL EFFECTS AND UPSLOPE FROM SELY WINDS. THIS
SHOULD LEAD TO A BLOOMING LOW CLOUD DECK AS THE NIGHT GOES ON.
WILL TIE THIS INTO LATTER PERIODS OF THE FORECAST WHICH CONTINUE
TO LOOK GOOD.
.PREVIOUS AFD...
HIGH PRESSURE OFF THE CANADIAN MARITIMES WILL CONTINUE TO WEDGE
DOWN THE EAST COAST. MEANWHILE...UPPER LOW CONTINUES TO ROTATE OFF
THE MID-ATLANTIC COAST. A WEAK SHORTWAVE WILL ROTATE ACROSS THE
REGION THIS AFTERNOON INTO TONIGHT. HIGH LEVEL CIRRUS IS SPREADING
ACROSS OUR REGION FROM AN APPROACHING UPPER LEVEL TROUGH AND
FLORIDA LOW PRESSURE CENTER. EASTERLY FLOW WILL CONTINUE TO PUSH
LOW LEVEL MOISTURE INTO OUR REGION TONIGHT INTO SATURDAY. USED A
BLEND OF THE GFS AND CANADIAN FOR CLOUD COVER TONIGHT. WENT WITH
LOWS CLOSE TO THE ADJMET WITH VALUES FROM LOWER 40S IN THE
NORTHWEST MOUNTAINS TO THE UPPER 40S IN THE SOUTHEAST. LOWS WILL
DEPEND PRIMARILY ON CLOUD COVER...AND ADVECTION AS A MODIFIED
MARITIME AIRMASS PROGRESSES INTO OUR REGION. ALLOWED FOR A LIGHT
POP ALONG THE SOUTHERN BLUE RIDGE WHERE CLOUD COVER WILL BE
RICHEST. WITH THE DEEP UPPER LOW TO OUR WEST REACHING THE
TENNESSEE VALLEY AND ENHANCED EASTERLY FLOW...KEPT SATURDAY COOL
WITH INCREASING CLOUDS. MODEL BLENDED THE ECMWF AND NAM FOR HIGH
SATURDAY WITH READINGS FROM LOWER 50S IN THE MOUNTAINS TO THE
UPPER 60S IN THE EAST. CONTINUED THE LIGHT POPS ACROSS THE
SOUTHWEST PORTIONS OF CWA ON SATURDAY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...
A CLOSED UPPER LEVEL LOW WILL MEANDER EASTWARD FROM THE LOWER
MISSISSIPPI RIVER VALLEY TOWARD THE SOUTHERN APPALACHIAN MOUNTAINS
DURING SATURDAY NIGHT INTO SUNDAY. POPS WERE BUMPED UPWARD TO
CATEGORICAL GIVEN THE GOOD AGREEMENT IN SPACE AND TIME BETWEEN THE
GFS AND THE ECMWF MODELS. IT WOULD NOT BE SURPRISING TO SEE A COUPLE
INCHES OF RAIN BETWEEN SATURDAY NIGHT AND MONDAY NIGHT ALONG THE
FAVORED UPSLOPE AREAS OF THE SOUTHERN BLUE RIDGE DUE TO DECENT
SOUTHEAST FLOW FROM A MOIST LOW LEVEL JET. WINDS COULD BECOME A
LITTLE GUSTY ALONG THE RIDGES DUE TO THIS JET.
THIS PROLONGED SPELL OF RAIN WILL MOST LIKELY COME IN OCCASIONAL
BANDS SPIRALING AROUND THE LOW. SOME OF THE HEAVIER BURSTS OF
RAINFALL COULD PRESENT A FLOODING ISSUE FOR SMALL RIVERS AND STREAMS
IN NORTHWEST NORTH CAROLINA AND SOUTHWEST VIRGINIA. FOG...LOW
CLOUDS...AND DRIZZLE SHOULD ACCOMPANY THE REMAINING PERIODS BETWEEN
BANDS. TEMPERATURES WERE HELD TO A SMALLER DIURNAL RANGE THAN
INDICATED IN THE MOS GUIDANCE...WITH HIGHS KEPT SEVERAL DEGREES
COOLER DUE TO THE PERSISTENT EASTERLY FLOW AT THE SURFACE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
BY TUESDAY...THE CUT OFF UPPER LEVEL LOW WILL WOBBLE EASTWARD OVER
THE CAROLINAS...AND APPROACH THE OUTER BANKS ON TUESDAY NIGHT. BOTH
THE 12Z GFS AND THE 00Z ECMWF ARE IN FAIRLY GOOD AGREEMENT WITH THE
TRACK AND RAINFALL COVERAGE OVER THE CWA...SO POPS WERE BUMPED
UPWARD TO LIKELY FOR TUESDAY BEFORE TAPERING TO CHANCE POPS ON
WEDNESDAY. THE UPPER LEVEL LOW WILL EVENTUALLY MERGE WITH THE
NORTHERN STREAM TO END THIS PROLONGED BLOCKING PATTERN AROUND
THURSDAY...BUT THE TIMING MAY BE A LITTLE OPTIMISTIC GIVEN HOW
SLOWLY THESE FEATURES TEND TO MOVE.
TEMPERATURES SHOULD INCREASE LATE IN THE WEEK WITH MORE SUNSHINE AND
A SOUTHWEST FLOW. HOWEVER...CHANCES OF SHOWERS WILL NOT SUBSIDE
COMPLETELY...DUE TO AN UPPER LEVEL TROUGH APPROACHING FROM THE WEST
BY FRIDAY. INSTABILITY APPEARS LOW IN THE MODEL SOUNDINGS DESPITE
THE INCREASING TEMPERATURES AND DEWPOINTS...SO THUNDER WAS HELD OUT
OF THE FORECAST FOR NOW...BUT THOSE CHANCES WILL BE MONITORED IN
FUTURE UPDATES. OVERALL...TEMPERATURES WERE KEPT TOWARD THE COOLER
SIDE OF GUIDANCE DUE TO THE ABUNDANT CLOUDINESS AND MOISTURE THAT
WILL BE EXPERIENCED IN THIS EXTENDED PERIOD.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
AS OF 730 PM EDT FRIDAY...
SC HAS PUSHED INTO THE AREA FROM THE EAST THIS EVENING...THOUGH
NOT QUITE MAKING IT TO KLWB AND KBLF. IT WAS ALSO STILL VFR SO NOT
A SIGNIFICANT IMPEDIMENT TO AVIATION INTERESTS. GFS 1000MB-850MB
LAYER RH SEEMS TO HAVE CAPTURED THIS FEATURE WELL AND INDICATES
A NOCTURNAL BLOOM OF SC POSSIBLE TONIGHT. MOS GUIDANCE ALSO SHOWS
THIS AND WILL INDICATE SOME MVFR CIGS EVERYWHERE EXCEPT KLWB AND
KBLF AS THEY LOOK TO BE ON THE FRINGES AND EXPECT THEM TO STAY
VFR. AS HAS BEEN THE CASE THE PAST TWO DAYS...THE TREND IS FOR
DIURNAL EFFECTS TO SCATTER OUT THE CLOUDS BEFORE THEY REDEVELOP
DURING THE AFTERNOON AND BELIEVE THIS WILL AGAIN BE THE CASE FOR
SATURDAY.
LOW LEVEL WINDS APPEAR TO SLACKEN BRIEFLY TOMORROW MORNING BEFORE
SURGING HIGHER LATE IN THE PERIOD. BELIEVE WE WILL SEE ANOTHER
BREEZY DAY WITH SELY FLOW.
EXTENDED AVIATION DISCUSSION...MAIN ATTENTION WILL BE APPROACHING
CLOSED LOW FROM THE MIDWEST/TN VALLEY REGION LATE IN THE
WEEKEND/EARLY NEXT WEEK. MODELS CONTINUE TO SUGGEST THAT LOWER CIGS
WILL ARRIVE BY SUNDAY AFTERNOON WITH AN EXTENDED PERIODS OF RAIN AND
WIDESPREAD IFR OR WORSE CIGS/VSBYS...ALONG WITH GUSTY E-SE WINDS
PERSISTING INTO TUESDAY AT THIS POINT. CONDITIONS SHOULD GRADUALLY
IMPROVE TO MVFR TOWARD MID AND LATE WEEK...WITH RAINFALL BECOMING
MORE SHOWERY IN NATURE WITH POSSIBLY ISOLD AFTERNOON TSRA TO ADD TO
THE PICTURE AT THAT TIME AS WELL.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/MBS
SHORT TERM...PW
LONG TERM...PW
AVIATION...CF/MBS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1106 PM CDT FRI MAY 3 2013
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 255 PM CDT FRI MAY 3 2013
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES AND POSSIBLE
THUNDERSTORMS THROUGH PERIOD.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWS UPPER LEVEL LOW CUTTING
OFF OVER THE CENTRAL PLAINS AND INDICATING GOOD FETCH OF MOISTURE
LIFTING NORTHWARD INTO THE UPPER MIDWEST AND GREAT LAKES REGION.
LATEST MOSAIC RADAR SHOWS RAIN ACROSS PORTIONS OF SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN INTO EASTERN IOWA AND NORTHERN
ILLINOIS. THIS IS IN RESPONSE TO DECENT MOISTURE TRANSPORT AND
CONVERGENCE IN THE 925-850MB LAYER PER 03.15Z RAP.
THE 03.12Z GFS/NAM ARE IN GOOD AGREEMENT IN MOVING UPPER LEVEL CUTOFF
LOW OVER THE SOUTHERN PLAINS AND SOUTHEAST UNITED STATES THROUGH
SATURDAY NIGHT. THE DETERMINISTIC MODELS CONTINUE TO SHOW A SERIES OF
SHORTWAVE TROUGHS WRAPPING AROUND UPPER LEVEL LOW INTO THE UPPER
MIDWEST. THE 03.12Z GFS/NAM AND 03.15Z RAP INDICATE THE AREA IS ON
THE NOSE OF DECENT MOISTURE TRANSPORT AND CONVERGENCE AT 925-850MB
LAYER TONIGHT INTO SATURDAY MORNING. THIS WILL CONTINUE TO SPREAD
RAIN/RAIN SHOWERS INTO THE FORECAST AREA THROUGH SATURDAY. ALONG
WITH THE SURGE OF MOISTURE...THE 03.12Z GFS/NAM ADVECT WARMER AIR
ALOFT INTO THE FORECAST AREA THIS EVENING AND INTO TONIGHT...WITH
925MB TEMPERATURES RISING TO PLUS 5 TO PLUS 13 DEGREES CELSIUS BY
12Z SATURDAY. ALL PRECIPITATION SHOULD REMAIN AS RAIN ACROSS THE
FORECAST AREA.
THE 03.12Z GFS/NAM INCREASE 0-6KM MOST UNSTABLE CAPE OF 300-500 J/KG
ACROSS SOUTHERN HALF OF FORECAST AREA AFTER 15Z SATURDAY. CANNOT
RULE OUT AN ISOLATED THUNDERSTORM ACROSS THIS AREA FROM 15Z
SATURDAY TO 00Z SUNDAY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 255 PM CDT FRI MAY 3 2013
SUNDAY...EASTERLY TO NORTHEASTERLY FLOW ALOFT DEVELOPS OVER REGION
AFTER 06Z SUNDAY AND WILL ADVECT DRIER AIR INTO THE REGION. WITH
925MB TEMPERATURES AROUND PLUS 13 DEGREES CELSIUS AND PARTIAL
SUNSHINE OVER FORECAST AREA...EXPECT HIGH TEMPERATURES TO WARM INTO
THE 60S.
MONDAY NIGHT THROUGH FRIDAY...MAIN FORECAST CONCERNS ARE
PRECIPITATION CHANCES WEDNESDAY INTO FRIDAY. THE 03.00Z
GFS/ECMWF/GEM ARE IN AGREEMENT IN DEVELOPING SPLIT UPPER LEVEL FLOW
OVER THE CONTINENTAL UNITED STATES THROUGH PERIOD. THE MAIN
DIFFERENCE IS THE 03.00Z ECMWF PUSHES A WEAK UPPER LEVEL LOW INTO
THE UPPER MIDWEST WEDNESDAY INTO THURSDAY AND THE GEM/GFS CONTINUE
TO SHOW RIDGING OVER THE REGION. THE 03.00Z ECMWF INDICATE WEAK
MOISTURE CONVERGENCE AND LIFT IN ASSOCIATED WITH WEAK UPPER LEVEL
LOW AND PRODUCES PRECIPITATION OVER THE AREA. THE 03.00Z GEFS
INDICATE UPPER LEVEL RIDGING OVER THE UPPER MIDWEST AND GREAT LAKES
REGION AND NO HINT OF A WEAK UPPER LEVEL LOW OVER THE AREA.
CONFIDENCE IN PRECIPITATION CHANCES WEDNESDAY AND THURSDAY IS
DECREASING AT THIS TIME. THE 03.00Z GEM/ECMWF/GFS ARE SUGGESTING
850MB TEMPERATURES PLUS 6 TO PLUS 10 DEGREES CELSIUS MONDAY NIGHT
THROUGH FRIDAY ACROSS THE AREA. EXPECT HIGH TEMPERATURES TO
CLIMBING TO AROUND 70 ACROSS FORECAST AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1106 PM CDT FRI MAY 3 2013
NUMEROUS SHOWERS CONTINUE TO STREAM NORTHWARD INTO THE TAF SITES...
THOUGH THEY ARE BECOMING MORE ISOLATED AROUND KLSE. THIS IS DUE TO
SOME DRIER AIR ALOFT TRYING TO WORK WESTWARD OUT OF LOWER
MICHIGAN. ALONG WITH THE DRIER AIR ALOFT IS WARMER AIR...WHICH IS
TRAPPING THE COOL...MOIST AIR AT THE SURFACE. AS A RESULT...LIFR
CEILINGS PERSIST AT KRST AND IFR/MVFR CEILINGS AT KLSE.
ANTICIPATING CEILINGS TO REMAIN STATUS QUO UNTIL LATE THIS MORNING
AND EARLY THIS AFTERNOON...WHICH IS WHEN THEY SHOULD BEGIN RISING
IN RESPONSE TO DAYTIME MIXING. THE BEST IMPROVEMENT IS EXPECTED AT
KLSE...CLOSER TO THE WARMER AND DRIER AIR COMING OUT OF LOWER
MICHIGAN. IN FACT...KLSE MAY EVEN GO VFR AT 23Z. HEADING INTO THE
EVENING HOURS...DIMINISHING WINDS AND NIGHTTIME COOLING RAISES
CONCERNS ABOUT FOG AND LOW STRATUS FORMATION...ESPECIALLY AT KRST
WITH MELTING SNOW. INCLUDED MVFR VISIBILITIES AT A MINIMUM FROM
BR...AND THESE COULD EASILY GO LOWER AFTER 06Z. WITH UNCERTAINTY
AT KRST OF THE LOW STRATUS NEVER BREAKING UP DURING THE
AFTERNOON...A GREATER CHANCE EXISTS THERE OF CEILINGS DROPPING
BACK DOWN TO IFR IN THE EVENING.
&&
.HYDROLOGY...
ISSUED AT 255 PM CDT FRI MAY 3 2013
PLAN ON RISES ALONG THE MISSISSIPPI RIVER AND ITS TRIBUTARIES
THROUGH THE WEEKEND...RESULTING FROM MELTING OF THE RECENT HEAVY
SNOW ALONG WITH RAINFALL AMOUNTS OF 0.75 TO 1 INCH EXPECTED OVER
THE REGION TONIGHT INTO SATURDAY NIGHT. A FEW SITES ALONG THE
MISSISSIPPI RIVER ARE EXPECTED TO RISE TO ABOVE AND TO NEAR FLOOD
STAGE. SOME TRIBUTARIES ARE FORECAST TO HAVE WITHIN BANK RISES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....DTJ
AVIATION...AJ
HYDROLOGY....DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
633 PM CDT FRI MAY 3 2013
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 255 PM CDT FRI MAY 3 2013
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES AND POSSIBLE
THUNDERSTORMS THROUGH PERIOD.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWS UPPER LEVEL LOW CUTTING
OFF OVER THE CENTRAL PLAINS AND INDICATING GOOD FETCH OF MOISTURE
LIFTING NORTHWARD INTO THE UPPER MIDWEST AND GREAT LAKES REGION.
LATEST MOSAIC RADAR SHOWS RAIN ACROSS PORTIONS OF SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN INTO EASTERN IOWA AND NORTHERN
ILLINOIS. THIS IS IN RESPONSE TO DECENT MOISTURE TRANSPORT AND
CONVERGENCE IN THE 925-850MB LAYER PER 03.15Z RAP.
THE 03.12Z GFS/NAM ARE IN GOOD AGREEMENT IN MOVING UPPER LEVEL CUTOFF
LOW OVER THE SOUTHERN PLAINS AND SOUTHEAST UNITED STATES THROUGH
SATURDAY NIGHT. THE DETERMINISTIC MODELS CONTINUE TO SHOW A SERIES OF
SHORTWAVE TROUGHS WRAPPING AROUND UPPER LEVEL LOW INTO THE UPPER
MIDWEST. THE 03.12Z GFS/NAM AND 03.15Z RAP INDICATE THE AREA IS ON
THE NOSE OF DECENT MOISTURE TRANSPORT AND CONVERGENCE AT 925-850MB
LAYER TONIGHT INTO SATURDAY MORNING. THIS WILL CONTINUE TO SPREAD
RAIN/RAIN SHOWERS INTO THE FORECAST AREA THROUGH SATURDAY. ALONG
WITH THE SURGE OF MOISTURE...THE 03.12Z GFS/NAM ADVECT WARMER AIR
ALOFT INTO THE FORECAST AREA THIS EVENING AND INTO TONIGHT...WITH
925MB TEMPERATURES RISING TO PLUS 5 TO PLUS 13 DEGREES CELSIUS BY
12Z SATURDAY. ALL PRECIPITATION SHOULD REMAIN AS RAIN ACROSS THE
FORECAST AREA.
THE 03.12Z GFS/NAM INCREASE 0-6KM MOST UNSTABLE CAPE OF 300-500 J/KG
ACROSS SOUTHERN HALF OF FORECAST AREA AFTER 15Z SATURDAY. CANNOT
RULE OUT AN ISOLATED THUNDERSTORM ACROSS THIS AREA FROM 15Z
SATURDAY TO 00Z SUNDAY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 255 PM CDT FRI MAY 3 2013
SUNDAY...EASTERLY TO NORTHEASTERLY FLOW ALOFT DEVELOPS OVER REGION
AFTER 06Z SUNDAY AND WILL ADVECT DRIER AIR INTO THE REGION. WITH
925MB TEMPERATURES AROUND PLUS 13 DEGREES CELSIUS AND PARTIAL
SUNSHINE OVER FORECAST AREA...EXPECT HIGH TEMPERATURES TO WARM INTO
THE 60S.
MONDAY NIGHT THROUGH FRIDAY...MAIN FORECAST CONCERNS ARE
PRECIPITATION CHANCES WEDNESDAY INTO FRIDAY. THE 03.00Z
GFS/ECMWF/GEM ARE IN AGREEMENT IN DEVELOPING SPLIT UPPER LEVEL FLOW
OVER THE CONTINENTAL UNITED STATES THROUGH PERIOD. THE MAIN
DIFFERENCE IS THE 03.00Z ECMWF PUSHES A WEAK UPPER LEVEL LOW INTO
THE UPPER MIDWEST WEDNESDAY INTO THURSDAY AND THE GEM/GFS CONTINUE
TO SHOW RIDGING OVER THE REGION. THE 03.00Z ECMWF INDICATE WEAK
MOISTURE CONVERGENCE AND LIFT IN ASSOCIATED WITH WEAK UPPER LEVEL
LOW AND PRODUCES PRECIPITATION OVER THE AREA. THE 03.00Z GEFS
INDICATE UPPER LEVEL RIDGING OVER THE UPPER MIDWEST AND GREAT LAKES
REGION AND NO HINT OF A WEAK UPPER LEVEL LOW OVER THE AREA.
CONFIDENCE IN PRECIPITATION CHANCES WEDNESDAY AND THURSDAY IS
DECREASING AT THIS TIME. THE 03.00Z GEM/ECMWF/GFS ARE SUGGESTING
850MB TEMPERATURES PLUS 6 TO PLUS 10 DEGREES CELSIUS MONDAY NIGHT
THROUGH FRIDAY ACROSS THE AREA. EXPECT HIGH TEMPERATURES TO
CLIMBING TO AROUND 70 ACROSS FORECAST AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 633 PM CDT FRI MAY 3 2013
RAIN SHOWERS CONTINUE TO STREAM NORTH INTO THE TAF SITES FROM LOW
PRESSURE IN THE MID-MISSISSIPPI RIVER VALLEY. MOISTURE FROM THIS
RAIN...AS WELL AS MELTING SNOW AT KRST...IS BECOMING TRAPPED BY
WARMER AIR FROM LOWER MICHIGAN PUSHING WESTWARD AROUND THIS LOW
ABOVE THE GROUND. AS A RESULT...CEILINGS HAVE BEEN SLOWLY LOWERING
LATE THIS AFTERNOON. EXPECT THIS LOWERING TO CONTINUE THROUGH THE
EVENING...BOTTOMING OUT AT IFR AT KLSE BEGINNING AT 02Z AND LIFR
AT KRST AROUND 06Z. THE MOISTURE FROM PERIODS OF RAIN THROUGH THE
NIGHT INTO SATURDAY MORNING SHOULD ALSO MAINTAIN MVFR VISIBILITIES
IN BR. LATE SATURDAY MORNING INTO THE AFTERNOON...EXPECT
IMPROVEMENT TO BOTH VISIBILITIES AND CEILINGS DUE TO DAYTIME
HEATING...AS WELL AS A PUSH OF WARMER AIR AT THE SURFACE FROM THE
EAST. KLSE...BEING CLOSER TO THE WARMER AIR...SHOULD CLIMB TO MVFR
WHILE KRST ONLY CLIMBS TO IFR. THE RAIN IS EXPECTED TO BECOME MORE
SCATTERED TOO AS DRIER AIR ALOFT ATTEMPTS TO PUSH WEST.
THEREFORE...HAVE SWITCHED TO A VCSH AT KLSE AT 19Z.
&&
.HYDROLOGY...
ISSUED AT 255 PM CDT FRI MAY 3 2013
PLAN ON RISES ALONG THE MISSISSIPPI RIVER AND ITS TRIBUTARIES
THROUGH THE WEEKEND...RESULTING FROM MELTING OF THE RECENT HEAVY
SNOW ALONG WITH RAINFALL AMOUNTS OF 0.75 TO 1 INCH EXPECTED OVER
THE REGION TONIGHT INTO SATURDAY NIGHT. A FEW SITES ALONG THE
MISSISSIPPI RIVER ARE EXPECTED TO RISE TO ABOVE AND TO NEAR FLOOD
STAGE. SOME TRIBUTARIES ARE FORECAST TO HAVE WITHIN BANK RISES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....DTJ
AVIATION...AJ
HYDROLOGY....DTJ
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1133 AM CDT THU MAY 2 2013
.UPDATE...
GUSTY NORTHEAST WINDS WILL CONTINUE THROUGH THE AFTERNOON. THEY ARE
IN RESPONSE TO TIGHT SURFACE PRESSURE GRADIENT WITH STRENGTHENING
LOW OVER CENTRAL IL AND ALSO SOUTHERN MI...AND HIGH PRESSURE
BUILDING INTO THE NORTHERN PLAINS. WINDS ARE NORTHERLY UP TO AROUND
2000 FEET AND SOUTHERLY JUST ABOVE THAT LEVEL.
SCATTERED THUNDERSTORMS FIRING UP OVER CENTRAL IL WHERE THERE IS
ONLY A SHALLOW CAP ARE MOVING NORTHWARD INTO SOUTHERN WI LATE THIS
MORNING. THEY ARE ELEVATED IN THE WARM LAYER AND TAPPING INTO SOME
ELEVATED CAPE UP TO 300 J/KG...SO EXPECT ISOLATED THUNDER AND BRIEF
MODERATE DOWNPOURS WITH THIS SCATTERED CONVECTION AS IT ROLLS
THROUGH AREAS OF SOUTHERN WI THIS AFTERNOON. SMALL HAIL IS NOT OUT
OF THE QUESTION WITH THIS ELEVATED CONVECTION.
RAIN CHANCES INCREASE ACROSS ALL OF SOUTHERN WI THIS EVENING AS A
500MB SHORTWAVE COINCIDES WITH WEAK WARM AIR ADVECTION.
&&
.AVIATION/18Z TAFS/...
MAIN UNCERTAINTY IS WHEN PRECIPITATION WILL ARRIVE AND WHEN WILL IFR
CEILINGS FINALLY DEVELOP.
GUSTY NORTHEAST WINDS WILL CONTINUE THROUGH THE AFTERNOON. THEY ARE
IN RESPONSE TO TIGHT SURFACE PRESSURE GRADIENT WITH STRENGTHENING
LOW OVER CENTRAL IL AND ALSO SOUTHERN MI...AND HIGH PRESSURE
BUILDING INTO THE NORTHERN PLAINS. WINDS ARE NORTHERLY UP TO AROUND
2000 FEET AND SOUTHERLY JUST ABOVE THAT LEVEL.
SCATTERED THUNDERSTORMS FIRING UP OVER CENTRAL IL WHERE THERE IS
ONLY A SHALLOW CAP ARE MOVING NORTHWARD INTO SOUTHERN WI LATE THIS
MORNING. THEY ARE ELEVATED IN THE WARM LAYER AND TAPPING INTO SOME
ELEVATED CAPE UP TO 300 J/KG...SO EXPECT ISOLATED THUNDER AND BRIEF
MODERATE DOWNPOURS WITH THIS SCATTERED CONVECTION AS IT ROLLS
THROUGH AREAS OF SOUTHERN WI THIS AFTERNOON. SMALL HAIL IS NOT
OUT OF THE QUESTION WITH THIS CONVECTION THIS AFTERNOON.
VFR CEILINGS SHOULD GRADUALLY LOWER AS CLOUDS INCREASE TODAY.
RAIN IS THEN SHOWN BY MODELS TO GROW IN COVERAGE DURING THE EVENING.
COMBINED WITH DIURNAL COOLING...STRATUS FORMATION SHOULD COMMENCE
WITH IFR TO PERHAPS LIFR CEILINGS.
&&
.PREV DISCUSSION... /ISSUED 336 AM CDT THU MAY 2 2013/
TODAY...FORECAST CONFIDENCE...MEDIUM
MAIN ISSUE IS WHEN TO RAMP UP THE POPS. AS BOTTOM OF TROUGH CREATES
100 METER 500 MB 12 HOUR HEIGHT FALLS IN KS...MAIN BAROCLINIC ZONE
ONLY DRIFTS EAST DURING THE DAY.
CURRENT BAND OF PRECIPITATION IS SITUATED IN WARM ADVECTION AND
FRONTOGENESIS IN 700-600 MB LAYER. NOT MUCH PRECIPITATION FALLING
OUTSIDE OF THAT ZONE...WITH EXCEPTION OF A COUPLE OF SHOWERS AND
THUNDERSTORMS IN MISSOURI. SOME OF THE MODEL GUIDANCE WAY OVERDONE
ON QPF OVERNIGHT FROM MISSOURI INTO MICHIGAN. GFS IS WORST
OFFENDER.
PRECIPITATION CHANCES TODAY ARE MAINLY TIED TO CONVECTION FORMING IN
WEAK WARM ADVECTION ZONE TO EAST OF MAIN POST FRONTAL PRECIPITATION
SHIELD. IT WOULD FORM IN WARM SECTOR OVER ILLINOIS AND THEN BECOME
ELEVATED OVER SHALLOW LOW LEVEL COLD AIR IN SOUTHERN WISCONSIN.
MOST OF THE GUIDANCE PRODUCES CONVECTION INCLUDING THE 4KM NMM AND
ARW CORES. HOWEVER...THE COVERAGE MAY NOT BE SUFFICIENT TO WARRANT
CATEGORICAL POPS. LATEST HRRR MODEL HAS NOTHING HAPPENING THROUGH
20Z...BUT THERE ARE A FEW SHOWERS FROM 15-18Z ON LOCAL WSWRF 4KM ARW
CORE. WILL TRY AND KEEP POPS HIGH THIS AFTERNOON FOR NOW...BUT MAY
HAVE TO CONSIDER CHOPPING THEM DOWN A BIT AT 12Z SHORT TERM UPDATE
BEFORE HEADING HOME.
CLOUDS AND NORTHEAST WINDS WILL MAKE IT FEEL MUCH DIFFERENT TODAY
THAN PAST COUPLE OF DAYS. 40S MUCH OF THE DAY NEAR THE
LAKE...BASICALLY CUTTING THE TEMPERATURE IN HALF FROM PAST COUPLE OF
DAYS.
TONIGHT...FORECAST CONFIDENCE...MEDIUM
CLOSED LOW BECOMES ESTABLISHED OVER KANSAS WITH FLOW GOING FROM
SOUTHWEST TO SOUTHERLY ALOFT OVER WISCONSIN. GRADUAL 40 METER
HEIGHT FALLS OVERNIGHT. MOST OF THE MODELS HAVE LIGHT PRECIPITATION
DURING THE NIGHT IN WEAK WARM ADVECTION REGIME. STRONGEST FORCING
SHOWN TO STAY CLOSER TO UPPER LOW FROM IOWA INTO MISSOURI.
BOTH NAM AND GFS SHOW SURFACE TEMPERATURES FALLING CLOSE TO FREEZING
IN FAR NORTHWEST AT SURFACE...BUT THAT AIR IS PRETTY SHALLOW. THERE
IS A NON-ZERO PROBABILITY OF FREEZING RAIN OUT WEST...BUT SREF
PROBABILITIES OF 60 TO 80% SEEM WAY TOO HIGH. LOOKS LIKE
TEMPERATURES GET DOWN TO 33 TO 35F WITH RAIN AND DEW POINTS AROUND
FREEZING...SO LITTLE HELP FROM WET BULB COOLING. FOR NOW WILL LEAVE
IT OUT.
FRIDAY THROUGH SUNDAY...FORECAST CONFIDENCE...MEDIUM
WILL BE EVEN COOLER FRIDAY...WITH SHOWERS EXPECTED ACROSS THE
FORECAST AREA AS LOW PRESSURE TO THE SOUTHWEST DRIFTS EASTWARD.
EAST WINDS WILL LIKELY KEEP TEMPS IN THE 40S NEAR THE LAKE...WITH
HIGHS STRUGGLING TO AROUND 50 ELSEWHERE.
SHOWER CHANCES WILL CONTINUE SATURDAY AS THE LOW REMAINS IN THE
REGION...THE BEST CHANCE IN THE SOUTHWEST. LOOKS LIKE SOME MILDER
TEMPS MAY SNEAK BACK INTO THE AREA...WITH HIGHS EXPECTED TO
RECOVER TO AROUND NORMAL MOST PLACES. WILL LIKELY SEE COOLER TEMPS
NEAR THE LAKE UNDER ONSHORE WINDS.
SHOULD BE MAINLY DRY SUNDAY...BUT KEPT SOME LOW POPS IN AS THE LOW
CONTINUES TO SLOWLY PULL AWAY. NEAR AVERAGE TEMPS SHOULD CONTINUE.
MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...MEDIUM
UPPER LOW WILL FINALLY BE OUT OF THE AREA BY MONDAY...WITH MODELS
TRENDING DRIER FOR EARLY NEXT WEEK. THERE IS INCREASING AGREEMENT
THAT HIGH PRESSURE MAY BRING PLEASANT WEATHER THROUGH AT LEAST
TUESDAY...SO LOWERED POPS ACCORDINGLY. MAY BE ABLE TO GET RID OF
THE POPS ALTOGETHER SOON IF THIS TREND CONTINUES. SHOULD SEE
WARMING TEMPS...POSSIBLY HITTING THE 70 DEGREE MARK BY TUESDAY.
AVIATION/12Z TAFS/...
MAIN UNCERTAINTY IS WHEN PRECIPITATION WILL ARRIVE AND WHEN WILL IFR
CEILINGS FINALLY DEVELOP.
VFR CEILINGS SHOULD GRADUALLY LOWER AS CLOUDS INCREASE TODAY. MANY
OF THE MODELS DEVELOP CONVECTIVE SHOWERS OVER ILLINOIS IN THE WARM
SECTOR AND THEN MOVE THEM NORTH INTO WISCONSIN DURING THE
AFTERNOON. RAIN IS THEN SHOWN TO GROW IN COVERAGE DURING THE
EVENING. COMBINED WITH DIURNAL COOLING...STRATUS FORMATION SHOULD
COMMENCE WITH IFR TO PERHAPS LIFR CEILINGS.
CURRENT GUSTY NORTHEAST SHOULD RELAX A BIT BUT STILL DECENT CHANCE
OF 20-25 KNOT GUSTS TODAY AND TONIGHT.
MARINE...
WINDS GUSTED TO NEAR GALE FORCE FOR A TIME BUT SHOULD SETTLE INTO
STEADY SMALL CRAFT ADVISORY LEVELS FROM NNE AND CONTINUE THROUGH
FRIDAY. FAVORABLE FETCH AND SLOW PROCESS OF SUBSIDING WAVES MAY
REQUIRE SCA TO BE EXTENDED INTO FRIDAY EVENING BUT PLENTY OF TIME TO
EVALUATE THAT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT FRIDAY FOR LMZ643>646.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...CRAVEN
FRIDAY THROUGH WEDNESDAY...DDV
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
336 AM CDT THU MAY 2 2013
.TODAY...FORECAST CONFIDENCE...MEDIUM
MAIN ISSUE IS WHEN TO RAMP UP THE POPS. AS BOTTOM OF TROUGH CREATES
100 METER 500 MB 12 HOUR HEIGHT FALLS IN KS...MAIN BAROCLINIC ZONE
ONLY DRIFTS EAST DURING THE DAY.
CURRENT BAND OF PRECIPITATION IS SITUATED IN WARM ADVECTION AND
FRONTOGENESIS IN 700-600 MB LAYER. NOT MUCH PRECIPITATION FALLING
OUTSIDE OF THAT ZONE...WITH EXCEPTION OF A COUPLE OF SHOWERS AND
THUNDERSTORMS IN MISSOURI. SOME OF THE MODEL GUIDANCE WAY OVERDONE
ON QPF OVERNIGHT FROM MISSOURI INTO MICHIGAN. GFS IS WORST
OFFENDER.
PRECIPITATION CHANCES TODAY ARE MAINLY TIED TO CONVECTION FORMING IN
WEAK WARM ADVECTION ZONE TO EAST OF MAIN POST FRONTAL PRECIPITATION
SHIELD. IT WOULD FORM IN WARM SECTOR OVER ILLINOIS AND THEN BECOME
ELEVATED OVER SHALLOW LOW LEVEL COLD AIR IN SOUTHERN WISCONSIN.
MOST OF THE GUIDANCE PRODUCES CONVECTION INCLUDING THE 4KM NMM AND
ARW CORES. HOWEVER...THE COVERAGE MAY NOT BE SUFFICIENT TO WARRANT
CATEGORICAL POPS. LATEST HRRR MODEL HAS NOTHING HAPPENING THROUGH
20Z...BUT THERE ARE A FEW SHOWERS FROM 15-18Z ON LOCAL WSWRF 4KM ARW
CORE. WILL TRY AND KEEP POPS HIGH THIS AFTERNOON FOR NOW...BUT MAY
HAVE TO CONSIDER CHOPPING THEM DOWN A BIT AT 12Z SHORT TERM UPDATE
BEFORE HEADING HOME.
CLOUDS AND NORTHEAST WINDS WILL MAKE IT FEEL MUCH DIFFERENT TODAY
THAN PAST COUPLE OF DAYS. 40S MUCH OF THE DAY NEAR THE
LAKE...BASICALLY CUTTING THE TEMPERATURE IN HALF FROM PAST COUPLE OF
DAYS.
.TONIGHT...FORECAST CONFIDENCE...MEDIUM
CLOSED LOW BECOMES ESTABLISHED OVER KANSAS WITH FLOW GOING FROM
SOUTHWEST TO SOUTHERLY ALOFT OVER WISCONSIN. GRADUAL 40 METER
HEIGHT FALLS OVERNIGHT. MOST OF THE MODELS HAVE LIGHT PRECIPITATION
DURING THE NIGHT IN WEAK WARM ADVECTION REGIME. STRONGEST FORCING
SHOWN TO STAY CLOSER TO UPPER LOW FROM IOWA INTO MISSOURI.
BOTH NAM AND GFS SHOW SURFACE TEMPERATURES FALLING CLOSE TO FREEZING
IN FAR NORTHWEST AT SURFACE...BUT THAT AIR IS PRETTY SHALLOW. THERE
IS A NON-ZERO PROBABILITY OF FREEZING RAIN OUT WEST...BUT SREF
PROBABILITIES OF 60 TO 80% SEEM WAY TOO HIGH. LOOKS LIKE
TEMPERATURES GET DOWN TO 33 TO 35F WITH RAIN AND DEW POINTS AROUND
FREEZING...SO LITTLE HELP FROM WET BULB COOLING. FOR NOW WILL LEAVE
IT OUT.
.FRIDAY THROUGH SUNDAY...FORECAST CONFIDENCE...MEDIUM
WILL BE EVEN COOLER FRIDAY...WITH SHOWERS EXPECTED ACROSS THE
FORECAST AREA AS LOW PRESSURE TO THE SOUTHWEST DRIFTS EASTWARD.
EAST WINDS WILL LIKELY KEEP TEMPS IN THE 40S NEAR THE LAKE...WITH
HIGHS STRUGGLING TO AROUND 50 ELSEWHERE.
SHOWER CHANCES WILL CONTINUE SATURDAY AS THE LOW REMAINS IN THE
REGION...THE BEST CHANCE IN THE SOUTHWEST. LOOKS LIKE SOME MILDER
TEMPS MAY SNEAK BACK INTO THE AREA...WITH HIGHS EXPECTED TO
RECOVER TO AROUND NORMAL MOST PLACES. WILL LIKELY SEE COOLER TEMPS
NEAR THE LAKE UNDER ONSHORE WINDS.
SHOULD BE MAINLY DRY SUNDAY...BUT KEPT SOME LOW POPS IN AS THE LOW
CONTINUES TO SLOWLY PULL AWAY. NEAR AVERAGE TEMPS SHOULD CONTINUE.
.MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...MEDIUM
UPPER LOW WILL FINALLY BE OUT OF THE AREA BY MONDAY...WITH MODELS
TRENDING DRIER FOR EARLY NEXT WEEK. THERE IS INCREASING AGREEMENT
THAT HIGH PRESSURE MAY BRING PLEASANT WEATHER THROUGH AT LEAST
TUESDAY...SO LOWERED POPS ACCORDINGLY. MAY BE ABLE TO GET RID OF
THE POPS ALTOGETHER SOON IF THIS TREND CONTINUES. SHOULD SEE
WARMING TEMPS...POSSIBLY HITTING THE 70 DEGREE MARK BY TUESDAY.
&&
.AVIATION/12Z TAFS/...
MAIN UNCERTAINTY IS WHEN PRECIPITATION WILL ARRIVE AND WHEN WILL IFR
CEILINGS FINALLY DEVELOP.
VFR CEILINGS SHOULD GRADUALLY LOWER AS CLOUDS INCREASE TODAY. MANY
OF THE MODELS DEVELOP CONVECTIVE SHOWERS OVER ILLINOIS IN THE WARM
SECTOR AND THEN MOVE THEM NORTH INTO WISCONSIN DURING THE
AFTERNOON. RAIN IS THEN SHOWN TO GROW IN COVERAGE DURING THE
EVENING. COMBINED WITH DIURNAL COOLING...STRATUS FORMATION SHOULD
COMMENCE WITH IFR TO PERHAPS LIFR CEILINGS.
CURRENT GUSTY NORTHEAST SHOULD RELAX A BIT BUT STILL DECENT CHANCE
OF 20-25 KNOT GUSTS TODAY AND TONIGHT.
&&
.MARINE...
WINDS GUSTED TO NEAR GALE FORCE FOR A TIME BUT SHOULD SETTLE INTO
STEADY SMALL CRAFT ADVISORY LEVELS FROM NNE AND CONTINUE THROUGH
FRIDAY. FAVORABLE FETCH AND SLOW PROCESS OF SUBSIDING WAVES MAY
REQUIRE SCA TO BE EXTENDED INTO FRIDAY EVENING BUT PLENTY OF TIME TO
EVALUATE THAT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT FRIDAY FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...CRAVEN
FRIDAY THROUGH WEDNESDAY...DDV
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 AM EDT SAT MAY 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM EDT SAT MAY 4 2013
AFTER BEING IN AN UNSETTLED WEATHER PATTERN FOR THE LAST SEVERAL
DAYS...THE AREA WILL TREND TOWARDS A DRIER PERIOD. WITH THE CUTOFF
LOW IS WELL TO OUR SOUTH AND THE NORTHERN STREAM JET FOCUSING
WELL NORTH INTO CANADA...THE AREA IS UNDER INCREASING UPPER LEVEL
RIDGING FROM THE RIDGE THAT HAS BEEN OVER EASTERN NORTH AMERICA.
THIS RIDGING...ALONG WITH SURFACE HIGH PRESSURE BUILDING OVER THE
UPPER GREAT LAKES WILL LEAD TO A DRIER AND WARMING TREND FOR THIS
WEEKEND.
THE FINAL PUSH FOR CENTRAL UPPER MICHIGAN IS CURRENTLY MOVING NNW
THIS MORNING AS THE 925MB WARM AIR ADVECTION SLOWLY PUSHES WEST.
FARTHER TO THE EAST...DRY MID LEVEL AIR SHOWN ON RAP ANALYSIS HAS
LED TO CLEAR SKIES OVER FAR EASTERN UPPER MICHIGAN ALONG THE
STALLED WARM FRONT AND ONLY MID TO HIGH CLOUDS OVER LAKE MICHIGAN
AND SOUTH CENTRAL UPPER MICHIGAN. LIGHT RAIN AND FREEZING RAIN IS
OCCURRING OVER THE FAR WEST...ALTHOUGH OBS AND RADAR ARE INDICATING
IT TO BE FAIRLY PATCHY. THERE ARE SOME STRONGER SHOWERS IN
SOUTHWEST WISCONSIN AND NORTHEAST IOWA...ASSOCIATED WITH SHORTWAVE
ENERGY PUSHING NORTHWEST THROUGH SOUTHWEST WISCONSIN AND THIS COULD
END UP BRUSHING THE FAR WESTERN CWA DURING THE AFTERNOON.
OTHERWISE...THE LIGHT PRECIPITATION OVER THE WEST WILL SLOWLY PUSH
OVER WESTERN LAKE SUPERIOR THROUGH THE DAY AND FALL AS RAIN WITH
THE 900-875MB TEMPS AROUND 8-9C. WITH LIGHT RAIN STILL OVER THE FAR
WEST AND TEMPERATURES BELOW FREEZING...WILL KEEP THE WINTER WEATHER
ADVISORY GOING UNTIL 12Z. ALL OF THE MODELS HAVE TEMPERATURES SLOWLY
RISING TO FREEZING OVER THE FAR WEST AT THAT TIME AND THEN SLOWLY
RISING ABOVE THAT AFTER SUNRISE. OTHERWISE...WITH THE LOW
LEVEL...SUB 900MB...NORTHEAST FLOW OVER THE WEST WILL KEEP THE LOW
CLOUDS IN PLACE THROUGH THE DAY.
THE DRIER AIR ALOFT SHOULD LEAD TO A DRY DAY ACROSS THE REST OF THE
CWA AND THE MAIN INFLUENCE ON THE WEATHER WILL BE THE LOCATION AND
DISSIPATION OF THE LOW CLOUDS OVER CENTRAL UPPER MICHIGAN. LATEST
TRENDS IN THE MODELS SHOW THAT THE LOW CLOUDS SHOULD DIMINISH
AROUND NOON OVER THE NORTH CENTRAL CWA. WITH THE EXPECTED LIGHT
NORTHERLY FLOW IN THE LOW LEVELS...NOT COMPLETELY CONFIDENT ON THAT
TIMING...SO ONLY WENT WITH PARTLY CLOUDY SKIES TOWARDS AFTERNOON.
BUT THE DRIER LOW LEVEL AIR TO THE SOUTHEAST...WONDERING IF THE
MODELS HAVE A HANDLE ON THE CLEARING IDEA AND THE FORECAST IS TOO
PESSIMISTIC. OTHERWISE...WOULD EXPECT MID-HIGH CLOUDS STREAMING
NORTHEAST ACROSS THE CENTRAL/EASTERN CWA THROUGH MUCH OF THE DAY.
AS FOR TEMPERATURES...EXPECT VALUES TO STRUGGLE TO REACH 40 OVER
THE FAR WEST UNDER THE CLOUDS. WITH THE BREAKS IN THE CLOUDS
OVER THE SOUTH CENTRAL AND EAST AND THE EXPECTED WESTWARD PUSH OF
THE 925/850MB TROUGH EARLY THIS MORNING AND THROUGH THE DAY ALLOWING
SOUTH-SOUTHEASTERLY FLOW TO DEVELOP OVER THE AREA...WOULD EXPECT
TEMPERATURES UNDER THE MAY SUN TO QUICKLY WARM INTO THE 50S/60S AND
A FEW LOWER 70S TOWARDS NEWBERRY. AS AN EXAMPLE...YESTERDAY WHERE
THE BREAKS IN THE CLOUDS WERE OVER THE EASTERN CWA...TEMPERATURES
WERE IN THE 50S AND LOWER 60S /DELTA...SCHOOLCRAFT...LUCE
COUNTIES/...BUT JUST TO THE WEST IN MARQUETTE COUNTY TEMPERATURES
WERE INN THE 30S. THUS...PINNING DOWN THE LOCATION/DISSIPATION OF
THE LOW CLOUDS CREATES A HUGE BUST POTENTIAL FOR HIGHS OVER THE
NORTH CENTRAL. NEAR LAKE SUPERIOR IN MARQUETTE COUNTY...THE NEAR
SURFACE FLOW WILL BE LIGHT AND NORTHERLY...WHICH WILL TRY TO KEEP
THE TEMPERATURES LOWER DUE TO LAKE SUPERIOR.
TONIGHT...HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA...WHILE THE
925/850MB TROUGH DISSIPATES OVER EASTERN MINNESOTA AND FAR WESTERN
LAKE SUPERIOR. THIS SHOULD LEAD TO A DRY NIGHT ACROSS MUCH OF THE
AREA AND LIKE TODAY...THE CLOUDS WILL BE ONE OF THE MAIN FORECAST
CONCERNS. MODELS SHOWING THE LOW CLOUDS REMAINING OVER THE FAR WEST
WITH THE LINGERING NORTHEASTERLY FLOW THROUGH THE NIGHT. EXPECT THAT
TO BE THE CASE AND WILL KEEP CLOUDY SKIES THERE. IN
ADDITION...THERE MAY BE SOME LIGHT DRIZZLE/RAIN OVER THE FAR WEST
WITH THE LOW CLOUDS IN THE EVENING...BUT OVERALL MUCH OF THE
PRECIPITATION SHOULD HAVE DIMINISHED WITH THE WEAKENING FORCING OVER
THE WESTERN LAKE. THE SLIGHTLY UPSLOPE NORTHEAST FLOW OVER THE
WEST...HAVE ADDED A MENTION OF PATCHY FOG DUE TO THE LOW
CLOUDS INTERACTING WITH THE HIGHER TERRAIN.
OVER THE NORTH CENTRAL...MODELS ARE SHOWING THE LOWER CLOUDS
REDEVELOPING TONIGHT WITH THE LIGHT NORTHERLY FLOW AND LINGERING LOW
LEVEL MOISTURE. WILL GO WITH A PARTLY-MOSTLY CLOUDY SKY AND THEN
DIMINISH IT HEADING SOUTH TOWARDS IRON MOUNTAIN. ALSO ADDED A
MENTION OF FOG TO THE HIGHER TERRAIN LOCATIONS.
FARTHER EAST AND AWAY FROM LAKE SUPERIOR...EXPECT MOSTLY CLEAR
SKIES WITH A SLIM POTENTIAL FOR FOG DUE TO THE EXPECTED MIXING OUT
TODAY AND DRIER AIR IN PLACE. THE FOG POTENTIAL WILL LIKELY DEPEND
ON IF FOG DEVELOPS OVER EASTERN LAKE SUPERIOR TODAY. IF IT
DOES...THE LIGHT NORTHERLY WINDS WILL DRAG IT SOUTH INTO THE
EASTERN CWA. DON/T HAVE THE CONFIDENCE TO ADD AT THIS POINT AND IT
WILL BE SOMETHING FOR THE DAY SHIFT TO WATCH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 416 AM EDT SAT MAY 4 2013
SUN...SFC HI PRES SINKING SLOWLY S FM ONTARIO WL SHIFT OVER LK SUP
BY LATE IN THE DAY UNDER UPR RDG AXIS TO THE N OF CLOSED LO SHIFTING
INTO THE SE CONUS. WITH THE ARRIVAL OF MORE ACYC FLOW/FRONTOLYSIS OF
LINGERING STNRY FNT AS WELL AS DIRUNAL HEATING...EXPECT MRNG LO CLDS
OVER THE NCENTRAL AND W TO SLOWLY DSPT. THESE CLDS WL BE MOST
PERSISTENT OVER THE HIER TERRAIN OF THE W WHERE LLVL MSTR IS A BIT
GREATER AND HOLD DOWN MAX TEMP RECOVERY WITH LLVL N WIND OFF LK SUP.
WL TEND TOWARD THE LOWER END OF GUIDANCE FOR TEMPS OVER THE NCENTRAL
AND W. MORE SUNSHINE OVER THE SCENTRAL AND E WITH H85 TEMPS UP TO
8-9C SHOULD ALLOW A SHARP CONTRAST TO THIS COOLER WX. EXPECT MAX
TEMPS UP TO 70 PER MIXING TO H85 ON FCST SDNGS AWAY FM THE LK
BREEZES THAT WL FORM IN PRESENCE OF WEAK GRADIENT ASSOCIATED WITH
THE HI.
SUN NGT THRU TUE...EXPECT DRY WX TO PREVAIL WITH NEAR STNRY HI PRES
UNDER UPR RDG AXIS EXTENDING E-W ACRS THE UPR LKS. ALTHOUGH H85
TEMPS ARE FCST TO REMAIN NEAR 8C...EXPECT A SLOW WARMING TREND AS
THE LLVLS SLOWLY MODERATE WITH HI SOLAR ANGLE. BUT WEAK PRES
GRADIENT UNDER THE SFC HI WL ALLOW LK BREEZES TO DVLP AND KEEP LK
SHORE COMMUNITIES COOLER. SOME MODELS GENERATE LGT QPF DURING THE
AFTNS WITH THE DAYTIME HEATING/LK BREEZE BNDRYS/LINGERING LLVL
MSTR...BUT WL NOT INCLUDE POPS ATTM GIVEN LARGE SCALE ACYC FLOW.
SUSPECT THERE WL BE QUITE A BIT OF DIURNAL CU. ALTHOUGH LGT WINDS WL
ALLOW FOR EFFICIENT RADIATIONAL COOLING...FCST PWATS REMAIN FAIRLY
HI ESPECIALLY OVER THE NW HALF. THE SHARPEST DIURNAL TEMP FALLS AT
NGT SHOULD BE OVER THE SCENTRAL AND E CLOSER TO THE CORE OF DRIER
AIR. OPTED TO INCLUDE A MENTION OF PATCHY FOG OVER THE INTERIOR WITH
THE LGT WINDS/FAIRLY SUBSTANTIAL LLVL MSTR.
TUE NGT INTO THU...APRCH OF WEAK SHRTWV FM THE W THAT WEAKENS RDG
OVER THE UPR LKS AND APRCH OF COLD FNT DROPPING S THRU ONTARIO ON
THE SRN FLANK OF DEEPENING UPR TROF CENTERED OVER HUDSON BAY WL
ALLOW A RETURN OF SOME -SHRA. SUSPECT THE BEST CHC FOR THESE SHRA WL
BE DURING THE DAY ON WED...WHEN DIURNAL HEATING WL BE IN PHASE WITH
DYNAMICS AHEAD OF THE APRCHG SHRTWV.
LATER THU THRU FRI...EXPECT A COOLING/DRYING TREND WITH N-NE WIND ON
THE SRN FLANK OF HI PRES BLDG INTO/THRU ONTARIO AND FCST H85 TEMPS
NEAR 0C BY FRI UNDER SLOWLY DEEPENING UPR TROF ACRS THE E HALF OF
NAMERICA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 129 AM EDT SAT MAY 4 2013
ABUNDANT LOW-LEVEL MOISTURE WILL LIKELY LINGER THRU MUCH OF THIS
FCST PERIOD...ESPECIALLY OVER WRN UPPER MI. AS A RESULT...KIWD WILL
LIKELY REMAIN UNDER IFR CONDITIONS THRU THIS EVENING...THOUGH IT`S
POSSIBLE CIGS MAY RISE TO LOW MVFR THIS AFTN. EXPECT OCNL
-FZDZ/-FZRA AT KIWD OVERNIGHT TO CHANGE TO -SHRA THIS MORNING AS
TEMPS SLOWLY RISE. PCPN SHOULD THEN END BY AFTN. AT KCMX...IFR
CONDITIONS WILL LIKELY PREVAIL THRU THE MORNING. SHOULD SEE SOME
IMPROVEMENT TO LOW MVFR THIS AFTN...AND IT`S POSSIBLE LOW CLOUDS
COULD SCATTER OUT AS DRIER AIR TRIES TO WORK WESTWARD. LOW
CONFIDENCE AT THIS POINT...SO LEFT MVFR CIGS IN PLACE INTO THE
EVENING. EXPECT OCNL -FZDZ TO TRANSITION TO OCNL -DZ AT KCMX IN THE
NEXT FEW HRS AS TEMPS SLOWLY RISE. AT KSAW...UPSLOPE NORTHERLY WINDS
WILL PROBABLY WORK TO MAINTAIN LIFR CONDITIONS THRU THE NIGHT ALONG
WITH -DZ/-SHRA AT TIMES. DRIER AIR WILL LIKELY MAKE INROADS INTO THE
AREA THIS AFTN...AND THERE IS A STRONGER MODEL TREND SUGGESTING THAT
WILL OCCUR. THUS...OPTED TO TREND FCST OPTIMISTIC TO VFR AT KSAW
THIS AFTN WITH LOW CLOUDS SCATTERING OUT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 AM EDT SAT MAY 4 2013
EXPECT N WINDS UP TO 20 KTS EARLY THIS MORNING TO DIMINISH THRU
TODAY/TONIGHT WITH APPROACH OF HI PRES FROM NW ONTARIO. WINDS WILL
THEN REMAIN LIGHT THRU NEXT WED WITH HI PRES/WEAK PRES GRADIENT
DOMINATING THE UPPER GREAT LAKES.
&&
.HYDROLOGY...
ISSUED AT 416 AM EDT SAT MAY 4 2013
THE STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER
AROUND WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL
REMAIN CONCERNS INTO AT LEAST EARLY NEXT WEEK...AND IN THE CASE OF
THE MICHIGAMME RIVER PERHAPS WELL INTO THE COMING WEEK. BUT
OTHERWISE RIVER LEVELS CONTINUE TO COME DOWN DESPITE SOME RECENT
HEAVY PRECIP THAT IMPACTED MAINLY THE W HALF OF UPR MI. IN FACT...A
DECENT AMOUNT OF WATER EQUIVALENT HAS OCCURRED SINCE THU OVER THE
WESTERN CWA...VCNTY OF IRONWOOD TO ONTONAGON...WITH OVER 2 INCHES
OVER FAR WESTERN GOGEBIC COUNTY. WILL HAVE TO ASSESS WHAT AFFECT THE
PRECIP WILL HAVE WHEN COMBINED WITH FURTHER MELTING OF ANY SUSTAINED
SNOWPACK WHEN TEMPS WARM SUN INTO NEXT WEEK. SNOW WATER EQUIVALENT
OF 8.8 INCHES IN PAINESDALE IN HOUGHTON COUNTY ON THURSDAY WITH 24
INCHES OF SNOW DEPTH...SO THE OTTER RIVER STILL HAS PLENTY OF SNOW
IN THE HEADWATERS WHICH MAY CAUSE ADDITIONAL PROBELMS AT CLLM4 IN
THE COMING DAYS.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING
FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...ROLFSON
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
131 AM EDT SAT MAY 4 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 418 PM EDT FRI MAY 3 2013
UPPER TROUGH CONTINUES TO SPLIT APART NEXT 24 HRS WITH UPPER LOW
FOCUSING OVER CNTRL MISSISSIPPI RIVER VALLEY. REGIONAL RADAR SHOWS
SWATH OF MAINLY RAIN FROM ILLINOIS INTO WISCONISN AND INTO WESTERN
UPR MICHIGAN AND INTO MINNESOTA ARROWHEAD. THIS PRECIP IS SUPPORTED
BY PERSISTENT H85-H7 FRONTOGENESIS AND RIGHT ENTRANCE REGION FROM
UPPER JET OVER ONTARIO. BOTH FEATURES ARE FORECAST TO DIMINISH INTO
SATURDAY AS UPPER LOW TO THE SOUTH BECOMES DOMINANT UPPER LEVEL
FEATURE.
ANALYSIS FROM RUC AND NAM INDICATING WARM LAYER IS WELL ABOVE 0C
SUGGESTS PTYPE OVER WESTERN UPR MICHIGAN SHOULD BE RAIN BUT REPORTS
FROM GOGEBIC INTO SOUTHERN HOUGHTON COUNTY SHOW IT IS NOT WITH LGT
SNOW OCCURRING. THESE AREAS LINE UP WELL WITH SUB ZERO 950-900MB
TEMPS SO KEPT MENTION OF SLEET/SNOW OVER FAR WESTERN UPR MICHIGAN
THROUGH EARLY MORNING HOURS BEFORE SHALLOWER COLD TEMPS WARM ABOVE
0C. OTHERWISE...RAIN WILL BE DOMINANT PTYPE ACROSS REST OF
CWA...MORE SCATTERED IN THE EASTERN HALF OF CWA. KEPT A MENTION OF
FZRA OVER INLAND WESTERN THIRD OF CWA. SINCE MAJORITY OF PRECIP WILL
OCCUR OVER WESTERN CWA AND SINCE THERE IS GOING TO BE CONTINUING
FZRA/SLEET/SNOW...CHANGING TO RAIN/FREEZING RAIN...OPTED TO KEEP
WINTER WEATHER ADVY OUT FOR GOGEBIC AND ONTONAGON COUNTIES THROUGH
12Z SATURDAY. COULD SEE SIMILAR PYTPE THIS EVENING FARTHER EAST
ACROSS KEWEENAW...BUT BASED ON UPSTREAM RADAR TRENDS AND BLEND OF
SHORT TERM MODELS...THINK THESE AREAS WILL MISS OUT ON HEAVIER QPF
AND BETTER CHANCE OF SLEET/ICE ACCUMS.
IMPROVING WEATHER ON SATURDAY...HOPEFULLY. LINGERING DIVERGENCE
ALOFT MAY STILL BRING SOME LGT RAIN OVER WEST AND NORTHWEST CWA.
SHOULD STAY DRY OVER THE EAST HALF. SIMILAR TO LAST COUPLE DAYS
SHOULD BE A WIDE TEMPERATURE RANGE FROM WEST TO EAST. BASED ON FCST
H85 TEMPS AND CLEARER SKIES EXPECTED...THINKING EASTERN INTERIOR
CWA MAY REACH MID 60S TO LOWER 70S. COOLER NORTH FLOW KEEPS WEST AND
CNTRL COOLER...BUT STILL A BIT WARMER THAN RECENT TEMPERATURES.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 418 PM EDT FRI MAY 3 2013
NAM SHOWS A CLOSED 500 MB LOW OVER NORTHERN CA AND ANOTHER OVER
NORTHERN ARKANSAS WITH A 500 MB RIDGE OVER THE LOWER GREAT LAKES.
THE 500 MB PATTERN OVER THE EAST HALF OF THE U.S. IS AN OMEGA BLOCK
00Z SUN AND DOES NOT MOVE MUCH ON SUNDAY EXCEPT TO TRY TO FORM A REX
BLOCK WITH THE LOW MOVING SLOWLY EAST UNDERNEATH THE RIDGE. THE REX
BLOCK THEN GETS ESTABLISHED ON MON. THIS FORECAST PERIOD FEATURES
DEEPER MOISTURE OVER THE WEST HALF OF THE CWA GRADUALLY DECREASING.
WILL KEEP SLIGHT CHANCE POPS OVER THE FAR WESTERN CWA SAT NIGHT WITH
THIS MOVING FURTHER WEST WITH TIME ON SUN. PCPN SHOULD BE ALL RAIN
BY THAT TIME. TEMPERATURES CONTINUE THE SLOW WARMING TREND WITH TIME
AND DRY WEATHER COMES IN FOR SUN INTO MON. DID NOT MAKE TOO MANY
CHANGES TO THE GOING FORECAST FOR TEMPERATURES EXCEPT DID LOWER LOWS
A BIT WITH THE COLDER MOS GUIDANCE FOR SAT NIGHT AND SUN NIGHT.
IN THE EXTENDED...ECMWF AND GFS SHOW A CLOSED 500 MB LOW OVER THE
SOUTHEAST U.S. 12Z TUE. THINGS GET INTERESTING OVER THE NORTHERN
PLAINS. 12Z TUE...ECMWF HAS A CLOSED 500 MB LOW NEAR SISSETON SD AND
THE GFS HAS A 500 MB RIDGE THERE INSTEAD. THIS DIFFERENCE CARRIES
INTO 12Z WED WITH THE ECMWF CONTINUING ITS SOLUTION OF A TROUGH IN
THE UPPER MISSISSIPPI VALLEY WITH THE 06Z GFS HAVING A CLOSED 500 MB
LOW OVER MISSOURI WHILE THE 00Z GFS STILL MAINTAINING A RIDGE OVER
THE CORNBELT. THE ECMWF TAKES THE TROUGH INTO THE UPPER GREAT LAKES
12Z THU WITH THE GFS MAINTAINING A FLAT 500 MB RIDGE OVER THE AREA.
THE 500 MB RIDGE GETS FLATTENED BY 12Z FRI WITH A BROAD 500 MB
TROUGH AND THE WESTERLIES GETTING PUSHED SOUTH INTO THE AREA.
CONFIDENCE REMAINS LOW WITH THIS EXTENDED FORECAST DUE TO THE 2 VERY
DIFFERENT MODEL SOLUTIONS. LOOKS DRY THROUGH TUE NIGHT BEFORE A COLD
FRONT HEADS SOUTH OUT OF CANADA AND BRINGS WITH IT A SLIGHT CHANCE
TO LOW CHANCE FOR PCPN WED INTO FRI. TEMPERATURES CONTINUE TO SLOWLY
WARM AND GO TO NEAR NORMAL BY THE END OF THE PERIOD. THE COLD FRONT
MOVES THROUGH WED NIGHT AND SLOWLY PUSHES SOUTH OF THE AREA THEN FOR
THU INTO FRI.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 129 AM EDT SAT MAY 4 2013
ABUNDANT LOW-LEVEL MOISTURE WILL LIKELY LINGER THRU MUCH OF THIS
FCST PERIOD...ESPECIALLY OVER WRN UPPER MI. AS A RESULT...KIWD WILL
LIKELY REMAIN UNDER IFR CONDITIONS THRU THIS EVENING...THOUGH IT`S
POSSIBLE CIGS MAY RISE TO LOW MVFR THIS AFTN. EXPECT OCNL
-FZDZ/-FZRA AT KIWD OVERNIGHT TO CHANGE TO -SHRA THIS MORNING AS
TEMPS SLOWLY RISE. PCPN SHOULD THEN END BY AFTN. AT KCMX...IFR
CONDITIONS WILL LIKELY PREVAIL THRU THE MORNING. SHOULD SEE SOME
IMPROVEMENT TO LOW MVFR THIS AFTN...AND IT`S POSSIBLE LOW CLOUDS
COULD SCATTER OUT AS DRIER AIR TRIES TO WORK WESTWARD. LOW
CONFIDENCE AT THIS POINT...SO LEFT MVFR CIGS IN PLACE INTO THE
EVENING. EXPECT OCNL -FZDZ TO TRANSITION TO OCNL -DZ AT KCMX IN THE
NEXT FEW HRS AS TEMPS SLOWLY RISE. AT KSAW...UPSLOPE NORTHERLY WINDS
WILL PROBABLY WORK TO MAINTAIN LIFR CONDITIONS THRU THE NIGHT ALONG
WITH -DZ/-SHRA AT TIMES. DRIER AIR WILL LIKELY MAKE INROADS INTO THE
AREA THIS AFTN...AND THERE IS A STRONGER MODEL TREND SUGGESTING THAT
WILL OCCUR. THUS...OPTED TO TREND FCST OPTIMISTIC TO VFR AT KSAW
THIS AFTN WITH LOW CLOUDS SCATTERING OUT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 PM EDT FRI MAY 3 2013
NO GALES SEEN DURING THIS FORECAST PERIOD. THE STRONGEST WINDS IN
THE PERIOD ARE THIS AFTERNOON WITH NORTHEAST WINDS BELOW 25 KNOTS. A
HIGH PRESSURE RIDGE SETTLES IN AND KEEPS STRONG SYSTEMS AWAY FROM
THE AREA.
&&
.HYDROLOGY...
ISSUED AT 418 PM EDT FRI MAY 3 2013
STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER AROUND
WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL REMAIN
CONCERNS INTO AT LEAST EARLY NEXT WEEK...BUT OTHERWISE RIVER LEVELS
CONTINUE TO COME DOWN. ACTUALLY...MICHIGAMME MAY REMAIN A CONCERN
THROUGH MOST OF NEXT WEEK. DECENT AMOUNT OF WATER EQUIVALENT HAS
OCCURRED LAST TWO DAYS OVER WESTERN CWA...VCNTY OF IRONWOOD TO
ONTONAGON...OVER 2 INCHES OVER FAR WESTERN GOGEBIC COUNTY. WILL HAVE
TO ASSESS WHAT AFFECT THE PRECIP WILL HAVE WHEN COMBINED WITH
FURTHER MELTING OF ANY SUSTAINED SNOWPACK WHEN TEMPS WARM INTO THE
60-70S SUN INTO NEXT WEEK. SNOW WATER EQUIVALENT OF 8.8 INCHES IN
PAINESDALE ON THURSDAY WITH 24 INCHES OF SNOW DEPTH...SO THE OTTER
RIVER STILL HAS PLENTY OF SNOW IN THE HEADWATERS WHICH MAY CAUSE
ADDITIONAL PROBELMS AT CLLM4 IN THE COMING DAYS.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING
FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...ROLFSON
MARINE...07
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
102 AM EDT SAT MAY 4 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN CENTERED ALONG THE NEW ENGLAND COAST
INTO THIS WEEKEND. A FRONTAL SYSTEM IN THE MISSISSIPPI VALLEY WILL
MOVE SLOWLY EAST...EVENTUALLY MOVING INTO THE CAROLINAS EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 950 PM FRIDAY...LATEST RAP MODEL CONTINUES TO SHOW LIGHT
PRECIPITATION REMAINING JUST OFFSHORE AS WEAKNESS IN PRESSURE
FIELD CONTINUES OFFSHORE. WILL CONTINUE A SLIGHT CHC POP TO
ACCOUNT FOR ANY SHOWERS TAKE MAY SNEAK ONSHORE OVERNIGHT. MAIN
CHANGE TO CURRENT FORECAST WILL BE TO LOWER MINIMUM TEMPERATURES A
COUPLE OF DEGREES BASED ON CURRENT FORECASTS AND FAIRLY LOW
DEWPOINT TEMPERATURES IN THE 40S. WITH BREEZY NORTHEAST WINDS...TEMPS
WILL FEEL EVEN COOLER OVERNIGHT...CERTAINLY NOT MAY-LIKE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TODAY/...
AS OF 3 PM FRI...NO SIGNIFICANT PATTERN CHANGE EXPECTED FOR SAT
WITH HIGH PRESSURE TO THE NORTH...LOW TO THE SOUTH...AND UPPER LOW
MOVING INTO THE SE STATES. BREEZY CONDITIONS EXPECTED AGAIN WITH
TIGHTENED GRADIENT. BASED ON LATEST GUIDANCE WILL CONTINUE POPS
FOR SAT...MAINLY E OF HWY 17 WITH CONTINUED ONSHORE FLOW AND WEAK
IMPULSE MOVING THROUGH AHEAD OF THE UPPER LOW. WILL CAP AT SLIGHT
CHANCE FOR NOW. SIMILAR HIGH TEMPS EXPECTED GENERALLY MID 60S TO
LOW 70S.
&&
.LONG TERM /TONIGHT THROUGH FRIDAY/...
OMEGA BLOCK WILL HOLD THRU SAT NIGHT WITH AXIS OF UPPER RDG OVER
THE AREA. BLOCK BREAKS DOWN LATER SUNDAY THRU EARLY NEXT WEEK AS
UPR LOW TO THE W SLIDES E AND UNDERCUTS THE RDG. MUCH OF THE
SUPPORT FOR STEADIER RAIN WILL REMAIN W OF REGION THRU SUN BUT A
SLIGHT TO LOW CHANCE POP OVER SOUTHERN AREAS SAT NIGHT WITH LOW
CHC POPS SPREADING NORTH THRU THE DAY ON SUNDAY AS AN AXIS OF
DEEPER MOISTURE LIFTS NORTH ACRS EASTERN NC. RAIN CHC INCREASE
SUN NIGHT AND ESPCLY MON AS BETTER FORCING AND MOISTURE AHEAD OF
UPPER LOW MOVES INTO REGION. DECENT AGREEMENT AMONG THE LATEST
MODEL RUNS FOR THE UPR LOW DRIFTING THRU THE SE STATES EARLY IN
THE WEEK THEN LIFTING NE ACRS THE FORECAST AREA ON WEDNESDAY SO
EXPECT PROLONGED PERIOD OF UNSETTLED WEATHER THRU MIDWEEK. KEPT
MENTION OF TSRA MAINLY DURING PEAK DIURNAL HEATING CYCLE MON-WED
GIVEN THE COOL POOL ALOFT. BEST LOW LVL WINDS ACROSS REGION MON
HOWEVER INSTAB LOOK WEAK. LOW LVL WINDS BECOME RATHER LIGHT TUE
AND WED HOWEVER WITH COLD POOL ALOFT MAY SEE DECENT CONVECTION
ESPCLY IF GET SOME SUN. OVERALL SEVERE THREATS LOOKS LIMITED BUT
NOT ZERO FIRST PART OF NEXT WEEK. HAVE RAMPED UP POPS TO LIKELY
MOST AREAS ON MON AND MAY NEED TO CONTINUE THE HIGHER POP TREND
INTO TUE IF MODELS CONTINUE IN GOOD AGREEMENT. DRYING TREND WILL
TAKE HOLD LATER IN THE WEEK AS THE UPR LOW FINALLY MOVES WELL NE
OF THE AREA.
TEMPS WILL BE BELOW NORMAL EARLY IN THE WEEK WITH HIGHS MAINLY
UPR 60S TO LOWER 70S. WARMING TREND WILL HIGHLIGHT THE MID TO LATE
WEEK PERIOD WITH AN UPPER RIDGE AGAIN BUILDING OVER THE AREA.
HIGHS MAY REACH NEAR 80 INLAND BY FRIDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH SATURDAY/...
AS OF 705 PM FRI...MODERATE CONFIDENCE THAT SOME MVFR AND PERHAPS
IFR CEILINGS WILL OCCUR TOWARD MORNING PER LATEST NUMERICAL
GUIDANCE AND PERSISTENCE FROM THE LAST FEW DAYS WITH LITTLE CHANGE
IN THE AIRMASS. BY MORNING...CONDITIONS WILL LIFT TO VFR AFTER
SUNRISE.
LONG TERM /SAT NIGHT THROUGH WEDNESDAY/...
GENERALLY VFR CONDITIONS SHOULD PREVAIL EARLY IN THE PERIOD BUT
FLYING CONDITIONS WILL DETERIORATE AS SHOWERS BECOME MORE
NUMEROUS LATE IN THE WEEKEND AND ESPECIALLY EARLY NEXT WEEK AHEAD
OF APPROACHING UPPER LOW.
&&
.MARINE...
SHORT TERM /THROUGH SATURDAY/...
AS OF 950 PM FRIDAY...GUSTY NORTHEAST WINDS CONTINUE ON AREA
WATERS WITH 1030+ MB HIGH HOLDING FIRM OVER CENTRAL NEW ENGLAND.
WINDS ARE GUSTING AS HIGH AS 32 KNOTS AT CAPE LOOKOUT WITH SEAS AS
HIGH AS 9 FEET AT THE BUOY 10 MILES NE OF DUCK. HAVE MADE JUST
MINOR TWEAKS TO THE MARINE FORECAST BASED ON CURRENT OBSERVATIONS
AS THE GUSTY WINDS AND ROUGH SEAS WILL CONTINUE THROUGH THE SHORT-
TERM PERIOD.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
POOR BOATING CONDITIONS MOST OF THE PERIOD. GUSTY NE WINDS CONT
SAT NIGHT WITH STRONG HIGH PRES TO THE N AND LOW PRES WELL TO THE
S. THE SFC LOW WILL GRAD LIFT N INTO MON AS UPR LOW APPROACHES
FROM THE W. WINDS WILL GRAD BECOME MORE E SUN TO SE MON WITH
SPEEDS INCREASING INTO THE 15 TO 20 KT RANGE. THE SFC LOW WILL
DRIFT OVER THE AREA BY TUE WITH WINDS BECOMING S/SW LESS THAN 15
KTS. THE LONG DURATION OF ONSHORE FLOW WILL KEEP SEAS ELEVATED
ABOVE SMALL CRAFT ADVISORY THRESHOLDS THRU AT LEAST TUESDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 1 AM SAT...STRONG NORTHEAST WINDS CONTINUE OVER THE SOUNDS.
EVEN IF WINDS LEVEL OFF A BIT TOWARD MORNING LEVELS WILL LIKELY
REMAIN ELEVATED THROUGH THE DAY. THEREFORE WILL EXTEND COASTAL
FLOOD ADVISORY NOW IN EFFECT FOR CRAVEN AND CARTERET COUNTIES TO
8PM THIS EVENING.
BASED ON BUOY REPORTS...WAVES ARE LIKELY MEETING SURF CRITERIA
ALONG THE COAST NORTH OF CAPE LOOKOUT SO HAVE ISSUED HIGH SURF
ADVISORY THROUGH 8PM THIS EVENING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...HIGH SURF ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NCZ095-103-
104.
COASTAL FLOOD ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NCZ093-
095.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL NOON EDT TUESDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...CQD
NEAR TERM...CTC
SHORT TERM...CQD
LONG TERM...BTC/RF
AVIATION...CTC/BTC/BM
MARINE...CTC/RF/CQD
TIDES/COASTAL FLOODING...HSA
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
141 AM EDT SAT MAY 4 2013
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL PERSIST OFF THE MID-ATLANTIC COAST
INTO THE WEEKEND...KEEPING A COOL...MARITIME...EAST FLOW ACROSS
THE REGION. A DEEP UPPER LOW WILL MOVE VERY SLOWLY FROM THE
TENNESSEE VALLEY LATE IN THE WEEKEND TO ALONG THE NORTH
CAROLINA OR SOUTHEAST VIRGINIA COAST BY THE MID OR LATE PART OF
NEXT WEEK. AN EXTENDED PERIOD OF LIGHT TO MODERATE
RAIN...OCCASIONALLY HEAVY...CAN BE EXPECTED ALONG WITH A
CONTINUATION OF COOL TEMPERATURES ACROSS THE REGION AS A RESULT.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 930PM...
SURGE OF SC MOVED ACROSS THE AREA FROM THE
EAST...AND LIKE THE WAY THE LATEST RUC HAS CAPTURED THAT FEATURE
SO WILL LEAN ON THAT MODEL FOR THE NEAR TERM SKY CONDITION. WITH
THAT IN MIND...EXPECTING THE INITIAL SC TO MOVE WEST WITH ANOTHER
SURGE OF MOISTURE OVERNIGHT COMBINING WITH DIURNAL EFFECTS AND
UPSLOPE FROM SELY WINDS. THIS SHOULD LEAD TO A BLOOMING LOW CLOUD
DECK AS THE NIGHT GOES ON. WILL TIE THIS INTO LATTER PERIODS OF
THE FORECAST WHICH CONTINUE TO LOOK GOOD.
.PREVIOUS AFD...
HIGH PRESSURE OFF THE CANADIAN MARITIMES WILL CONTINUE TO WEDGE
DOWN THE EAST COAST. MEANWHILE...UPPER LOW CONTINUES TO ROTATE OFF
THE MID-ATLANTIC COAST. A WEAK SHORTWAVE WILL ROTATE ACROSS THE
REGION THIS AFTERNOON INTO TONIGHT. HIGH LEVEL CIRRUS IS SPREADING
ACROSS OUR REGION FROM AN APPROACHING UPPER LEVEL TROUGH AND
FLORIDA LOW PRESSURE CENTER. EASTERLY FLOW WILL CONTINUE TO PUSH
LOW LEVEL MOISTURE INTO OUR REGION TONIGHT INTO SATURDAY. USED A
BLEND OF THE GFS AND CANADIAN FOR CLOUD COVER TONIGHT. WENT WITH
LOWS CLOSE TO THE ADJMET WITH VALUES FROM LOWER 40S IN THE
NORTHWEST MOUNTAINS TO THE UPPER 40S IN THE SOUTHEAST. LOWS WILL
DEPEND PRIMARILY ON CLOUD COVER...AND ADVECTION AS A MODIFIED
MARITIME AIRMASS PROGRESSES INTO OUR REGION. ALLOWED FOR A LIGHT
POP ALONG THE SOUTHERN BLUE RIDGE WHERE CLOUD COVER WILL BE
RICHEST. WITH THE DEEP UPPER LOW TO OUR WEST REACHING THE
TENNESSEE VALLEY AND ENHANCED EASTERLY FLOW...KEPT SATURDAY COOL
WITH INCREASING CLOUDS. MODEL BLENDED THE ECMWF AND NAM FOR HIGH
SATURDAY WITH READINGS FROM LOWER 50S IN THE MOUNTAINS TO THE
UPPER 60S IN THE EAST. CONTINUED THE LIGHT POPS ACROSS THE
SOUTHWEST PORTIONS OF CWA ON SATURDAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...
A CLOSED UPPER LEVEL LOW WILL MEANDER EASTWARD FROM THE LOWER
MISSISSIPPI RIVER VALLEY TOWARD THE SOUTHERN APPALACHIAN MOUNTAINS
DURING SATURDAY NIGHT INTO SUNDAY. POPS WERE BUMPED UPWARD TO
CATEGORICAL GIVEN THE GOOD AGREEMENT IN SPACE AND TIME BETWEEN THE
GFS AND THE ECMWF MODELS. IT WOULD NOT BE SURPRISING TO SEE A COUPLE
INCHES OF RAIN BETWEEN SATURDAY NIGHT AND MONDAY NIGHT ALONG THE
FAVORED UPSLOPE AREAS OF THE SOUTHERN BLUE RIDGE DUE TO DECENT
SOUTHEAST FLOW FROM A MOIST LOW LEVEL JET. WINDS COULD BECOME A
LITTLE GUSTY ALONG THE RIDGES DUE TO THIS JET.
THIS PROLONGED SPELL OF RAIN WILL MOST LIKELY COME IN OCCASIONAL
BANDS SPIRALING AROUND THE LOW. SOME OF THE HEAVIER BURSTS OF
RAINFALL COULD PRESENT A FLOODING ISSUE FOR SMALL RIVERS AND STREAMS
IN NORTHWEST NORTH CAROLINA AND SOUTHWEST VIRGINIA. FOG...LOW
CLOUDS...AND DRIZZLE SHOULD ACCOMPANY THE REMAINING PERIODS BETWEEN
BANDS. TEMPERATURES WERE HELD TO A SMALLER DIURNAL RANGE THAN
INDICATED IN THE MOS GUIDANCE...WITH HIGHS KEPT SEVERAL DEGREES
COOLER DUE TO THE PERSISTENT EASTERLY FLOW AT THE SURFACE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
BY TUESDAY...THE CUT OFF UPPER LEVEL LOW WILL WOBBLE EASTWARD OVER
THE CAROLINAS...AND APPROACH THE OUTER BANKS ON TUESDAY NIGHT. BOTH
THE 12Z GFS AND THE 00Z ECMWF ARE IN FAIRLY GOOD AGREEMENT WITH THE
TRACK AND RAINFALL COVERAGE OVER THE CWA...SO POPS WERE BUMPED
UPWARD TO LIKELY FOR TUESDAY BEFORE TAPERING TO CHANCE POPS ON
WEDNESDAY. THE UPPER LEVEL LOW WILL EVENTUALLY MERGE WITH THE
NORTHERN STREAM TO END THIS PROLONGED BLOCKING PATTERN AROUND
THURSDAY...BUT THE TIMING MAY BE A LITTLE OPTIMISTIC GIVEN HOW
SLOWLY THESE FEATURES TEND TO MOVE.
TEMPERATURES SHOULD INCREASE LATE IN THE WEEK WITH MORE SUNSHINE AND
A SOUTHWEST FLOW. HOWEVER...CHANCES OF SHOWERS WILL NOT SUBSIDE
COMPLETELY...DUE TO AN UPPER LEVEL TROUGH APPROACHING FROM THE WEST
BY FRIDAY. INSTABILITY APPEARS LOW IN THE MODEL SOUNDINGS DESPITE
THE INCREASING TEMPERATURES AND DEWPOINTS...SO THUNDER WAS HELD OUT
OF THE FORECAST FOR NOW...BUT THOSE CHANCES WILL BE MONITORED IN
FUTURE UPDATES. OVERALL...TEMPERATURES WERE KEPT TOWARD THE COOLER
SIDE OF GUIDANCE DUE TO THE ABUNDANT CLOUDINESS AND MOISTURE THAT
WILL BE EXPERIENCED IN THIS EXTENDED PERIOD.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 130 AM EDT SATURDAY...
SE FLOW REMAINS STRONG EARLY THIS MORNING ALTHOUGH LOWER CLOUDS
REMAIN MORE SCATTERED THAN BKN EXCEPT AROUND HSP. WINDS WILL BE
GUSTY MOST OF THE THIS PERIOD AS GRADIENT REMAINS TIGHT BETWEEN
SFC HIGH OVER NEW ENGLAND AND THE LOW OVER THE MIDWEST. THINK A
SMALL PERIOD OF BKN MVFR CIGS ARE POSSIBLE THIS MORNING AT BCB/ROA
BUT OVERALL LOOKS LIKE VFR CIGS WILL BE THE RULE THIS PERIOD.
EXTENDED AVIATION DISCUSSION...MAIN ATTENTION WILL BE APPROACHING
CLOSED LOW FROM THE MIDWEST/TN VALLEY REGION LATE IN THE
WEEKEND/EARLY NEXT WEEK. MODELS CONTINUE TO SUGGEST THAT LOWER
CIGS WILL ARRIVE BY SUNDAY AFTERNOON WITH AN EXTENDED PERIODS OF
RAIN AND WIDESPREAD IFR OR WORSE CIGS/VSBYS...ALONG WITH GUSTY
E-SE WINDS PERSISTING INTO TUESDAY AT THIS POINT. CONDITIONS
SHOULD GRADUALLY IMPROVE TO MVFR TOWARD MID AND LATE WEEK...WITH
RAINFALL BECOMING MORE SHOWERY IN NATURE WITH POSSIBLY ISOLD
AFTERNOON TSRA TO ADD TO THE PICTURE AT THAT TIME AS WELL.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/MBS
SHORT TERM...PW
LONG TERM...PW
AVIATION...CF/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
256 AM CDT SAT MAY 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 256 AM CDT SAT MAY 4 2013
THE MAIN FOCUS FOR TODAY INTO TONIGHT IS WITH PRECIPITATION
CHANCES...THE POTENTIAL FOR DENSE FOG...AND HOW HIGH TEMPERATURES
WILL CLIMB TODAY.
A DEEPENING CUT OFF MID LEVEL LOW CONTINUES TO SLOWLY CHURN
EASTWARD ALONG THE MISSOURI/ARKANSAS BORDER AS A SURFACE LOW HAS
RETROGRADED TO THE WEST ACROSS CENTRAL ILLINOIS TOWARD THE
MISSOURI/IOWA BORDER. THIS HAS PULLED THE 925/850MB MOISTURE
TRANSPORT NORTHWEST INTO THE UPPER MISSISSIPPI VALLEY REGION WITH
SCATTERED CONVECTION DEVELOPING ALONG AND NORTH OF IT. AS THE
MID/LOW LEVEL LOW CONTINUES TO WRAP UP TODAY...THIS MOISTURE SURGE
SHOULD PUSH THE WEST WITH THE CONVECTION TRACKING THAT WAY AS
WELL EARLY THIS MORNING.
BEYOND THAT...AM NOT VERY CONFIDENT THAT THERE WILL BE MUCH IN THE
WAY OF CONVECTION ACROSS THE REGION WITH THE MAIN UPPER LEVEL
FORCING FROM THE LOW REMAINING TO THE SOUTH AND ANOTHER SHORT WAVE
STAYING WELL TO THE NORTH. THE MAIN FEATURE TO HELP TRIGGER ANY
SHOWERS/STORMS APPEARS TO BE WITH AN INVERTED SURFACE TROUGH THAT
IS CURRENTLY ALIGNED ALONG THE EASTERN SHORE OF LAKE MICHIGAN. THE
04.00Z NAM/GFS SHOW THIS FEATURE TRACKING WEST TODAY INTO
WISCONSIN AND SHOW SOME PRECIPITATION FORMING ALONG IT.
HOWEVER...THESE SAME MODELS BRING SURFACE DEW POINTS INTO THE LOW
60S AND DEVELOP A FEW HUNDRED J/KG OF SURFACE BASED CAPE IN AN
UNCAPPED ENVIRONMENT. MODIFYING THOSE SOUNDINGS TO HAVING DEW
POINTS IN THE LOW TO MID 50S YIELDS A CAPPED ENVIRONMENT WITH NO
SURFACE BASED CAPE. CURRENT DEW POINT ANALYSIS SHOWS THAT THE MAIN
SLUG OF HIGHER SURFACE DEW POINTS ARE CONFINED TO BEING JUST
EAST/NORTHEAST OF THE SURFACE LOW IN CENTRAL ILLINOIS WITH MID TO
UPPER 40S ELSEWHERE. WITH THIS SURFACE LOW DROPPING SOUTH
TODAY...EXPECT THAT THE BETTER CHANCES FOR CONVECTION WILL FOLLOW
IT AS WELL. SOME OF THE 04.00Z MESO-MODELS...SUCH AS THE NSSL
WRF...DO NOT CONVECT TODAY WHILE THE NMM AND THE 04.06Z HRRR DO
FORM SOME CONVECTION ALONG THE INSTABILITY AXIS WHERE THESE MODELS
FEATURE SURFACE DEW POINTS IN THE LOW 60S. BASED ON ALL
THIS...TRIED TO TREND PRECIPITATION CHANCES DOWN A BIT FOR TODAY.
TEMPERATURE-WISE FOR TODAY...FAIRLY HIGH BUST POTENTIAL BOTH WITH
POSSIBLY BEING TOO HIGH ON TEMPERATURES AND TOO LOW DEPENDING ON
THE LOCATION. LOW LEVEL EASTERLY WINDS WILL PULL A WARMER AIR
MASS INTO THE REGION TODAY...BUT HOW FAR WEST THIS AIR MAKES IT IS
THE MAIN QUESTION. HIGHS YESTERDAY IN LOWER MICHIGAN WERE IN THE
70S WHERE THIS AIR MASS WILL ORIGINATE FROM. HOW MUCH THE SNOW
PACK MELTS TODAY ACROSS SOUTHEAST MINNESOTA/NORTHEAST IOWA/NORTH
CENTRAL WISCONSIN WILL ALSO LIMIT TEMPERATURES A BIT THERE AS
WELL. DID NOT STRAY TOO FAR FROM GUIDANCE ON TEMPERATURES FOR
TODAY WITH HIGHER TEMPERATURES RANGING FROM THE UPPER 60S IN
EASTERN WISCONSIN TO THE UPPER 40S IN CENTRAL MINNESOTA.
WITH ALL OF THIS WARM AIR MOVING OVER A SNOW PACK AND OTHERWISE
MOIST SURFACES...EXPECT THAT THERE WILL BE FOG TONIGHT ACROSS MUCH
OF THE REGION. THE HIGHEST POTENTIAL FOR DENSE FOG WILL BE IN
THE AFOREMENTIONED SNOW PACK REGION WHERE A LOW LEVEL INVERSION
SHOULD TRAP MUCH OF THIS MOISTURE NEAR THE SURFACE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 256 AM CDT SAT MAY 4 2013
FOR SUNDAY INTO MONDAY...THE MAIN QUESTION WILL BE WHETHER ANY
CONVECTION WILL CONTINUE TO DEVELOP ALONG THE STALLED OUT INVERTED
SURFACE TROUGH WHICH APPEARS TO SET UP ALONG THE MISSISSIPPI
RIVER. THE 04.00Z NAM/GFS WANT TO DEVELOP MORE PRECIPITATION ALONG
THIS FEATURE BUT STILL HAVE WAY TOO HIGH OF SURFACE DEW POINTS
ALONG IT AND SHOW TOO HIGH OF INSTABILITY WITH NO CAPPING AS A
RESULT. KEPT THE FORECAST DRY OVER THIS PERIOD...BUT WILL HAVE TO
WATCH FOR ANY TRENDS THERE IN THE SURFACE DEW POINTS.
OTHERWISE...THE CORE OF THE UPPER LEVEL LOW PROPAGATES TO THE
SOUTHEAST INTO THE MIDDLE OF NEXT WEEK WITH ANOTHER CUT OFF LOW
MEANDERING THROUGH THE ROCKIES. CONDITIONS SHOULD MAINLY BE DRY
INTO MID WEEK BEFORE THE TROUGH PUSHES BACK TO THE EAST.
PRECIPITATION CHANCES MAY BE A BIT OVERDONE FROM WEDNESDAY THROUGH
FRIDAY...BUT BOTH THE 04.00Z GFS AND ECMWF DEVELOP SHOWERS
THROUGHOUT THE PERIOD WITH THE LOW MOVING IN ALONG WITH A COLD
FRONT DROPPING DOWN FROM CANADA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1106 PM CDT FRI MAY 3 2013
NUMEROUS SHOWERS CONTINUE TO STREAM NORTHWARD INTO THE TAF SITES...
THOUGH THEY ARE BECOMING MORE ISOLATED AROUND KLSE. THIS IS DUE TO
SOME DRIER AIR ALOFT TRYING TO WORK WESTWARD OUT OF LOWER
MICHIGAN. ALONG WITH THE DRIER AIR ALOFT IS WARMER AIR...WHICH IS
TRAPPING THE COOL...MOIST AIR AT THE SURFACE. AS A RESULT...LIFR
CEILINGS PERSIST AT KRST AND IFR/MVFR CEILINGS AT KLSE.
ANTICIPATING CEILINGS TO REMAIN STATUS QUO UNTIL LATE THIS MORNING
AND EARLY THIS AFTERNOON...WHICH IS WHEN THEY SHOULD BEGIN RISING
IN RESPONSE TO DAYTIME MIXING. THE BEST IMPROVEMENT IS EXPECTED AT
KLSE...CLOSER TO THE WARMER AND DRIER AIR COMING OUT OF LOWER
MICHIGAN. IN FACT...KLSE MAY EVEN GO VFR AT 23Z. HEADING INTO THE
EVENING HOURS...DIMINISHING WINDS AND NIGHTTIME COOLING RAISES
CONCERNS ABOUT FOG AND LOW STRATUS FORMATION...ESPECIALLY AT KRST
WITH MELTING SNOW. INCLUDED MVFR VISIBILITIES AT A MINIMUM FROM
BR...AND THESE COULD EASILY GO LOWER AFTER 06Z. WITH UNCERTAINTY
AT KRST OF THE LOW STRATUS NEVER BREAKING UP DURING THE
AFTERNOON...A GREATER CHANCE EXISTS THERE OF CEILINGS DROPPING
BACK DOWN TO IFR IN THE EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS POCATELLO ID
840 AM MDT SAT MAY 4 2013
.SHORT TERM...TODAY THROUGH TUESDAY. A QUICK UPDATE THIS MORNING TO
START THE LAKE WIND ADVISORY RIGHT AWAY THIS MORNING GIVEN THE
VERIFYING NE WINDS ALREADY BLOWING ACROSS THE AMERICAN FALLS
RESERVOIR. SEE PREVIOUS DISCUSSION BELOW. HUSTON
THUNDER WILL BE A CONCERN TODAY AS LAPSE RATES STEEPEN DURING THE
DAY. COLD AIR ALOFT ASSOCIATED WITH UPPER LOW WILL HELP DESTABILIZE
THE ATMOSPHERE AS WELL. IMPULSES OF ENERGY FROM THE UPPER LOW SHOULD
BE ENOUGH TO TRIGGER THE CONVECTION TODAY...AND IT IS PICKED UP
FAIRLY WELL BY THE HRRR AND WRF. EVEN MOS GUIDANCE IS ADVERTISING
FAIRLY HIGH THUNDER CHANCES. INFLUENCE OF THE UPPER LOW WILL ALSO BE
FELT TOMORROW AFTERNOON WITH THUNDER AGAIN IN THE FORECAST. MODELS
ARE ALSO HINTING AT A STRENGTHENING NORTHEASTERLY WIND THAT WILL
BRING AMERICAN FALLS RESERVOIR INTO LAKE WIND ADVISORY CRITERIA.
LOW-LEVEL LAPSE RATES AND BOUNDARY LAYER WINDS FAVOR THESE STRONGER
WINDS AS THE SURFACE GRADIENT TIGHTENS ACROSS THE AREA. MOS GUIDANCE
FOR KPIH SEEM A BIT ON THE LOW SIDE GIVEN THE CONDITIONS. HINSBERGER
.LONG TERM...TUESDAY THROUGH FRIDAY. THE CLOSED LOW THAT HAS
RETROGRADED TO THE CALIFORNIA COAST BEGINS TO REVERSE DIRECTION AND
MOVE INLAND. THE ECMWF TRACKS THE LOW TO SOUTH CENTRAL COLORADO BY
WEDNESDAY AFTERNOON WHILE THE GFS IS A LITTLE SLOWER AND MOVES THE
LOW MORE TOWARDS WEST CENTRAL COLORADO BY THE SAME TIME PERIOD. WRAP
AROUND MOISTURE EXTENDS ACROSS SOUTHEAST IDAHO BOTH TUESDAY AND
WEDNESDAY...THE GFS EXTENDS CONVECTION CLOSER TO THE MONTANA LINE.
MOISTURE HAS DEEPENED ENOUGH THAT CONVECTIVE SHOWERS COULD PRODUCE
.10 TO .20 INCH OF RAIN THAT WOULD BE MOSTLY NEEDED BUT PERHAPS
ACCELERATE SNOW RUN OFF FROM THE MOUNTAINS. AIR MASS IS UNSTABLE
ENOUGH FOR A SLIGHT CHANCE OF THUNDERSTORMS EACH DAY. THE LOW
CONTINUES TO MOVE EAST THURSDAY AND FRIDAY. THIS LEAVES SOUTHEAST
IDAHO UNDER NORTHWEST FLOW AND A HIGH PRESSURE RIDGE JUST OFF THE
WASHINGTON COAST. MOIST AIR LINGERS OVER THE FORECAST AREA WITH AND
MINOR DISTURBANCES PASSING TO THE NORTH THAT COULD CONTRIBUTE TO
ISOLATED SHOWERS IN THIS AREA. RS
&&
AVIATION...UPPER LOW THIS MORNING CENTERED ROUGHLY NEAR KSUN IN THE
PROCESS OF CLOSING OFF AND RETROGRADING TOWARDS THE CALIFORNIA COAST
THROUGH 05/06Z. SCATTERED RAIN SHOWERS FORMING IN BANDS AROUND THE
LOW AND WHERE TERRAIN FAVORED LIFT IS. SNOW LEVELS MAINLY NEAR 7200
FT MSL THIS MORNING INCREASING TO NEAR 7800 FT THIS AFTERNOON.
CEILINGS EXPECTED TO REMAIN VFR AT TAF SITES BUT WILL OBSCURE HIGHER
MOUNTAINS EVERYWHERE. CAN NOT RULE OUT AN ISOLATED THUNDERSTORM THIS
AFTERNOON. SOME STABILIZING OF SHOWERS TONIGHT AFTER 05/08Z...THEN
REDEVELOPING AFTER 05/18Z. RS
&&
.PIH WATCHES/WARNINGS/ADVISORIES...LAKE WIND ADVISORY UNTIL 9 PM MDT
THIS EVENING IDZ021.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
749 AM EDT SAT MAY 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM EDT SAT MAY 4 2013
AFTER BEING IN AN UNSETTLED WEATHER PATTERN FOR THE LAST SEVERAL
DAYS...THE AREA WILL TREND TOWARDS A DRIER PERIOD. WITH THE CUTOFF
LOW IS WELL TO OUR SOUTH AND THE NORTHERN STREAM JET FOCUSING
WELL NORTH INTO CANADA...THE AREA IS UNDER INCREASING UPPER LEVEL
RIDGING FROM THE RIDGE THAT HAS BEEN OVER EASTERN NORTH AMERICA.
THIS RIDGING...ALONG WITH SURFACE HIGH PRESSURE BUILDING OVER THE
UPPER GREAT LAKES WILL LEAD TO A DRIER AND WARMING TREND FOR THIS
WEEKEND.
THE FINAL PUSH FOR CENTRAL UPPER MICHIGAN IS CURRENTLY MOVING NNW
THIS MORNING AS THE 925MB WARM AIR ADVECTION SLOWLY PUSHES WEST.
FARTHER TO THE EAST...DRY MID LEVEL AIR SHOWN ON RAP ANALYSIS HAS
LED TO CLEAR SKIES OVER FAR EASTERN UPPER MICHIGAN ALONG THE
STALLED WARM FRONT AND ONLY MID TO HIGH CLOUDS OVER LAKE MICHIGAN
AND SOUTH CENTRAL UPPER MICHIGAN. LIGHT RAIN AND FREEZING RAIN IS
OCCURRING OVER THE FAR WEST...ALTHOUGH OBS AND RADAR ARE INDICATING
IT TO BE FAIRLY PATCHY. THERE ARE SOME STRONGER SHOWERS IN
SOUTHWEST WISCONSIN AND NORTHEAST IOWA...ASSOCIATED WITH SHORTWAVE
ENERGY PUSHING NORTHWEST THROUGH SOUTHWEST WISCONSIN AND THIS COULD
END UP BRUSHING THE FAR WESTERN CWA DURING THE AFTERNOON.
OTHERWISE...THE LIGHT PRECIPITATION OVER THE WEST WILL SLOWLY PUSH
OVER WESTERN LAKE SUPERIOR THROUGH THE DAY AND FALL AS RAIN WITH
THE 900-875MB TEMPS AROUND 8-9C. WITH LIGHT RAIN STILL OVER THE FAR
WEST AND TEMPERATURES BELOW FREEZING...WILL KEEP THE WINTER WEATHER
ADVISORY GOING UNTIL 12Z. ALL OF THE MODELS HAVE TEMPERATURES SLOWLY
RISING TO FREEZING OVER THE FAR WEST AT THAT TIME AND THEN SLOWLY
RISING ABOVE THAT AFTER SUNRISE. OTHERWISE...WITH THE LOW
LEVEL...SUB 900MB...NORTHEAST FLOW OVER THE WEST WILL KEEP THE LOW
CLOUDS IN PLACE THROUGH THE DAY.
THE DRIER AIR ALOFT SHOULD LEAD TO A DRY DAY ACROSS THE REST OF THE
CWA AND THE MAIN INFLUENCE ON THE WEATHER WILL BE THE LOCATION AND
DISSIPATION OF THE LOW CLOUDS OVER CENTRAL UPPER MICHIGAN. LATEST
TRENDS IN THE MODELS SHOW THAT THE LOW CLOUDS SHOULD DIMINISH
AROUND NOON OVER THE NORTH CENTRAL CWA. WITH THE EXPECTED LIGHT
NORTHERLY FLOW IN THE LOW LEVELS...NOT COMPLETELY CONFIDENT ON THAT
TIMING...SO ONLY WENT WITH PARTLY CLOUDY SKIES TOWARDS AFTERNOON.
BUT THE DRIER LOW LEVEL AIR TO THE SOUTHEAST...WONDERING IF THE
MODELS HAVE A HANDLE ON THE CLEARING IDEA AND THE FORECAST IS TOO
PESSIMISTIC. OTHERWISE...WOULD EXPECT MID-HIGH CLOUDS STREAMING
NORTHEAST ACROSS THE CENTRAL/EASTERN CWA THROUGH MUCH OF THE DAY.
AS FOR TEMPERATURES...EXPECT VALUES TO STRUGGLE TO REACH 40 OVER
THE FAR WEST UNDER THE CLOUDS. WITH THE BREAKS IN THE CLOUDS
OVER THE SOUTH CENTRAL AND EAST AND THE EXPECTED WESTWARD PUSH OF
THE 925/850MB TROUGH EARLY THIS MORNING AND THROUGH THE DAY ALLOWING
SOUTH-SOUTHEASTERLY FLOW TO DEVELOP OVER THE AREA...WOULD EXPECT
TEMPERATURES UNDER THE MAY SUN TO QUICKLY WARM INTO THE 50S/60S AND
A FEW LOWER 70S TOWARDS NEWBERRY. AS AN EXAMPLE...YESTERDAY WHERE
THE BREAKS IN THE CLOUDS WERE OVER THE EASTERN CWA...TEMPERATURES
WERE IN THE 50S AND LOWER 60S /DELTA...SCHOOLCRAFT...LUCE
COUNTIES/...BUT JUST TO THE WEST IN MARQUETTE COUNTY TEMPERATURES
WERE INN THE 30S. THUS...PINNING DOWN THE LOCATION/DISSIPATION OF
THE LOW CLOUDS CREATES A HUGE BUST POTENTIAL FOR HIGHS OVER THE
NORTH CENTRAL. NEAR LAKE SUPERIOR IN MARQUETTE COUNTY...THE NEAR
SURFACE FLOW WILL BE LIGHT AND NORTHERLY...WHICH WILL TRY TO KEEP
THE TEMPERATURES LOWER DUE TO LAKE SUPERIOR.
TONIGHT...HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA...WHILE THE
925/850MB TROUGH DISSIPATES OVER EASTERN MINNESOTA AND FAR WESTERN
LAKE SUPERIOR. THIS SHOULD LEAD TO A DRY NIGHT ACROSS MUCH OF THE
AREA AND LIKE TODAY...THE CLOUDS WILL BE ONE OF THE MAIN FORECAST
CONCERNS. MODELS SHOWING THE LOW CLOUDS REMAINING OVER THE FAR WEST
WITH THE LINGERING NORTHEASTERLY FLOW THROUGH THE NIGHT. EXPECT THAT
TO BE THE CASE AND WILL KEEP CLOUDY SKIES THERE. IN
ADDITION...THERE MAY BE SOME LIGHT DRIZZLE/RAIN OVER THE FAR WEST
WITH THE LOW CLOUDS IN THE EVENING...BUT OVERALL MUCH OF THE
PRECIPITATION SHOULD HAVE DIMINISHED WITH THE WEAKENING FORCING OVER
THE WESTERN LAKE. THE SLIGHTLY UPSLOPE NORTHEAST FLOW OVER THE
WEST...HAVE ADDED A MENTION OF PATCHY FOG DUE TO THE LOW
CLOUDS INTERACTING WITH THE HIGHER TERRAIN.
OVER THE NORTH CENTRAL...MODELS ARE SHOWING THE LOWER CLOUDS
REDEVELOPING TONIGHT WITH THE LIGHT NORTHERLY FLOW AND LINGERING LOW
LEVEL MOISTURE. WILL GO WITH A PARTLY-MOSTLY CLOUDY SKY AND THEN
DIMINISH IT HEADING SOUTH TOWARDS IRON MOUNTAIN. ALSO ADDED A
MENTION OF FOG TO THE HIGHER TERRAIN LOCATIONS.
FARTHER EAST AND AWAY FROM LAKE SUPERIOR...EXPECT MOSTLY CLEAR
SKIES WITH A SLIM POTENTIAL FOR FOG DUE TO THE EXPECTED MIXING OUT
TODAY AND DRIER AIR IN PLACE. THE FOG POTENTIAL WILL LIKELY DEPEND
ON IF FOG DEVELOPS OVER EASTERN LAKE SUPERIOR TODAY. IF IT
DOES...THE LIGHT NORTHERLY WINDS WILL DRAG IT SOUTH INTO THE
EASTERN CWA. DON/T HAVE THE CONFIDENCE TO ADD AT THIS POINT AND IT
WILL BE SOMETHING FOR THE DAY SHIFT TO WATCH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 416 AM EDT SAT MAY 4 2013
SUN...SFC HI PRES SINKING SLOWLY S FM ONTARIO WL SHIFT OVER LK SUP
BY LATE IN THE DAY UNDER UPR RDG AXIS TO THE N OF CLOSED LO SHIFTING
INTO THE SE CONUS. WITH THE ARRIVAL OF MORE ACYC FLOW/FRONTOLYSIS OF
LINGERING STNRY FNT AS WELL AS DIRUNAL HEATING...EXPECT MRNG LO CLDS
OVER THE NCENTRAL AND W TO SLOWLY DSPT. THESE CLDS WL BE MOST
PERSISTENT OVER THE HIER TERRAIN OF THE W WHERE LLVL MSTR IS A BIT
GREATER AND HOLD DOWN MAX TEMP RECOVERY WITH LLVL N WIND OFF LK SUP.
WL TEND TOWARD THE LOWER END OF GUIDANCE FOR TEMPS OVER THE NCENTRAL
AND W. MORE SUNSHINE OVER THE SCENTRAL AND E WITH H85 TEMPS UP TO
8-9C SHOULD ALLOW A SHARP CONTRAST TO THIS COOLER WX. EXPECT MAX
TEMPS UP TO 70 PER MIXING TO H85 ON FCST SDNGS AWAY FM THE LK
BREEZES THAT WL FORM IN PRESENCE OF WEAK GRADIENT ASSOCIATED WITH
THE HI.
SUN NGT THRU TUE...EXPECT DRY WX TO PREVAIL WITH NEAR STNRY HI PRES
UNDER UPR RDG AXIS EXTENDING E-W ACRS THE UPR LKS. ALTHOUGH H85
TEMPS ARE FCST TO REMAIN NEAR 8C...EXPECT A SLOW WARMING TREND AS
THE LLVLS SLOWLY MODERATE WITH HI SOLAR ANGLE. BUT WEAK PRES
GRADIENT UNDER THE SFC HI WL ALLOW LK BREEZES TO DVLP AND KEEP LK
SHORE COMMUNITIES COOLER. SOME MODELS GENERATE LGT QPF DURING THE
AFTNS WITH THE DAYTIME HEATING/LK BREEZE BNDRYS/LINGERING LLVL
MSTR...BUT WL NOT INCLUDE POPS ATTM GIVEN LARGE SCALE ACYC FLOW.
SUSPECT THERE WL BE QUITE A BIT OF DIURNAL CU. ALTHOUGH LGT WINDS WL
ALLOW FOR EFFICIENT RADIATIONAL COOLING...FCST PWATS REMAIN FAIRLY
HI ESPECIALLY OVER THE NW HALF. THE SHARPEST DIURNAL TEMP FALLS AT
NGT SHOULD BE OVER THE SCENTRAL AND E CLOSER TO THE CORE OF DRIER
AIR. OPTED TO INCLUDE A MENTION OF PATCHY FOG OVER THE INTERIOR WITH
THE LGT WINDS/FAIRLY SUBSTANTIAL LLVL MSTR.
TUE NGT INTO THU...APRCH OF WEAK SHRTWV FM THE W THAT WEAKENS RDG
OVER THE UPR LKS AND APRCH OF COLD FNT DROPPING S THRU ONTARIO ON
THE SRN FLANK OF DEEPENING UPR TROF CENTERED OVER HUDSON BAY WL
ALLOW A RETURN OF SOME -SHRA. SUSPECT THE BEST CHC FOR THESE SHRA WL
BE DURING THE DAY ON WED...WHEN DIURNAL HEATING WL BE IN PHASE WITH
DYNAMICS AHEAD OF THE APRCHG SHRTWV.
LATER THU THRU FRI...EXPECT A COOLING/DRYING TREND WITH N-NE WIND ON
THE SRN FLANK OF HI PRES BLDG INTO/THRU ONTARIO AND FCST H85 TEMPS
NEAR 0C BY FRI UNDER SLOWLY DEEPENING UPR TROF ACRS THE E HALF OF
NAMERICA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 747 AM EDT SAT MAY 4 2013
LOW CLOUDS...ALTERNATE LANDING MINS...WILL BE IN PLACE AT ALL THREE
SITES TO START TO PERIOD. BUT AS DRIER AIR MOVES WEST ACROSS UPPER
MICHIGAN...WOULD EXPECT CONDITIONS TO IMPROVE AT KSAW FIRST...WHERE
SKIES WILL LIKELY SCATTER OR CLEAR OUT THIS AFTERNOON. FARTHER
WEST...CONFIDENCE ON SCATTERING OUT AT THE OTHER TWO SITES IS
LIMITED...BUT THERE IS A DECENT CHANCE OF DIURNAL MIXING TO PUSH
KCMX TO MVFR CONDITIONS AND POSSIBLY EVEN KIWD. ALSO...THE FOG AT
KIWD THIS MORNING SHOULD COME TO AN END FAIRLY QUICKLY THIS MORNING
DUE TO DIURNAL MIXING.
ONCE DAYTIME HEATING IS LOST...IT APPEARS THAT THE LOW CLOUDS AND
FOG WILL TRY TO SETTLE BACK INTO THE TAF SITES WITH THE LIGHT
NORTHERLY FLOW OFF LAKE SUPERIOR. HIT LOW CLOUDS/FOG THE HARDEST AT
KIWD DUE TO THE FOG THIS MORNING AND WITH THEM BEING UNDER THE
DEEPEST LOW LEVEL MOISTURE. MOISTURE IS A LITTLE LESS CERTAIN AT
KCMX/KSAW...BUT STILL THINK THE CEILINGS AND MAYBE VISIBILITIES WILL
REACH IFR DURING THE OVERNIGHT HOURS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 AM EDT SAT MAY 4 2013
EXPECT N WINDS UP TO 20 KTS EARLY THIS MORNING TO DIMINISH THRU
TODAY/TONIGHT WITH APPROACH OF HI PRES FROM NW ONTARIO. WINDS WILL
THEN REMAIN LIGHT THRU NEXT WED WITH HI PRES/WEAK PRES GRADIENT
DOMINATING THE UPPER GREAT LAKES.
&&
.HYDROLOGY...
ISSUED AT 416 AM EDT SAT MAY 4 2013
THE STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER
AROUND WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL
REMAIN CONCERNS INTO AT LEAST EARLY NEXT WEEK...AND IN THE CASE OF
THE MICHIGAMME RIVER PERHAPS WELL INTO THE COMING WEEK. BUT
OTHERWISE RIVER LEVELS CONTINUE TO COME DOWN DESPITE SOME RECENT
HEAVY PRECIP THAT IMPACTED MAINLY THE W HALF OF UPR MI. IN FACT...A
DECENT AMOUNT OF WATER EQUIVALENT HAS OCCURRED SINCE THU OVER THE
WESTERN CWA...VCNTY OF IRONWOOD TO ONTONAGON...WITH OVER 2 INCHES
OVER FAR WESTERN GOGEBIC COUNTY. WILL HAVE TO ASSESS WHAT AFFECT THE
PRECIP WILL HAVE WHEN COMBINED WITH FURTHER MELTING OF ANY SUSTAINED
SNOWPACK WHEN TEMPS WARM SUN INTO NEXT WEEK. SNOW WATER EQUIVALENT
OF 8.8 INCHES IN PAINESDALE IN HOUGHTON COUNTY ON THURSDAY WITH 24
INCHES OF SNOW DEPTH...SO THE OTTER RIVER STILL HAS PLENTY OF SNOW
IN THE HEADWATERS WHICH MAY CAUSE ADDITIONAL PROBELMS AT CLLM4 IN
THE COMING DAYS.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING
FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
654 AM CDT SAT MAY 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 256 AM CDT SAT MAY 4 2013
THE MAIN FOCUS FOR TODAY INTO TONIGHT IS WITH PRECIPITATION
CHANCES...THE POTENTIAL FOR DENSE FOG...AND HOW HIGH TEMPERATURES
WILL CLIMB TODAY.
A DEEPENING CUT OFF MID LEVEL LOW CONTINUES TO SLOWLY CHURN
EASTWARD ALONG THE MISSOURI/ARKANSAS BORDER AS A SURFACE LOW HAS
RETROGRADED TO THE WEST ACROSS CENTRAL ILLINOIS TOWARD THE
MISSOURI/IOWA BORDER. THIS HAS PULLED THE 925/850MB MOISTURE
TRANSPORT NORTHWEST INTO THE UPPER MISSISSIPPI VALLEY REGION WITH
SCATTERED CONVECTION DEVELOPING ALONG AND NORTH OF IT. AS THE
MID/LOW LEVEL LOW CONTINUES TO WRAP UP TODAY...THIS MOISTURE SURGE
SHOULD PUSH THE WEST WITH THE CONVECTION TRACKING THAT WAY AS
WELL EARLY THIS MORNING.
BEYOND THAT...AM NOT VERY CONFIDENT THAT THERE WILL BE MUCH IN THE
WAY OF CONVECTION ACROSS THE REGION WITH THE MAIN UPPER LEVEL
FORCING FROM THE LOW REMAINING TO THE SOUTH AND ANOTHER SHORT WAVE
STAYING WELL TO THE NORTH. THE MAIN FEATURE TO HELP TRIGGER ANY
SHOWERS/STORMS APPEARS TO BE WITH AN INVERTED SURFACE TROUGH THAT
IS CURRENTLY ALIGNED ALONG THE EASTERN SHORE OF LAKE MICHIGAN. THE
04.00Z NAM/GFS SHOW THIS FEATURE TRACKING WEST TODAY INTO
WISCONSIN AND SHOW SOME PRECIPITATION FORMING ALONG IT.
HOWEVER...THESE SAME MODELS BRING SURFACE DEW POINTS INTO THE LOW
60S AND DEVELOP A FEW HUNDRED J/KG OF SURFACE BASED CAPE IN AN
UNCAPPED ENVIRONMENT. MODIFYING THOSE SOUNDINGS TO HAVING DEW
POINTS IN THE LOW TO MID 50S YIELDS A CAPPED ENVIRONMENT WITH NO
SURFACE BASED CAPE. CURRENT DEW POINT ANALYSIS SHOWS THAT THE MAIN
SLUG OF HIGHER SURFACE DEW POINTS ARE CONFINED TO BEING JUST
EAST/NORTHEAST OF THE SURFACE LOW IN CENTRAL ILLINOIS WITH MID TO
UPPER 40S ELSEWHERE. WITH THIS SURFACE LOW DROPPING SOUTH
TODAY...EXPECT THAT THE BETTER CHANCES FOR CONVECTION WILL FOLLOW
IT AS WELL. SOME OF THE 04.00Z MESO-MODELS...SUCH AS THE NSSL
WRF...DO NOT CONVECT TODAY WHILE THE NMM AND THE 04.06Z HRRR DO
FORM SOME CONVECTION ALONG THE INSTABILITY AXIS WHERE THESE MODELS
FEATURE SURFACE DEW POINTS IN THE LOW 60S. BASED ON ALL
THIS...TRIED TO TREND PRECIPITATION CHANCES DOWN A BIT FOR TODAY.
TEMPERATURE-WISE FOR TODAY...FAIRLY HIGH BUST POTENTIAL BOTH WITH
POSSIBLY BEING TOO HIGH ON TEMPERATURES AND TOO LOW DEPENDING ON
THE LOCATION. LOW LEVEL EASTERLY WINDS WILL PULL A WARMER AIR
MASS INTO THE REGION TODAY...BUT HOW FAR WEST THIS AIR MAKES IT IS
THE MAIN QUESTION. HIGHS YESTERDAY IN LOWER MICHIGAN WERE IN THE
70S WHERE THIS AIR MASS WILL ORIGINATE FROM. HOW MUCH THE SNOW
PACK MELTS TODAY ACROSS SOUTHEAST MINNESOTA/NORTHEAST IOWA/NORTH
CENTRAL WISCONSIN WILL ALSO LIMIT TEMPERATURES A BIT THERE AS
WELL. DID NOT STRAY TOO FAR FROM GUIDANCE ON TEMPERATURES FOR
TODAY WITH HIGHER TEMPERATURES RANGING FROM THE UPPER 60S IN
EASTERN WISCONSIN TO THE UPPER 40S IN CENTRAL MINNESOTA.
WITH ALL OF THIS WARM AIR MOVING OVER A SNOW PACK AND OTHERWISE
MOIST SURFACES...EXPECT THAT THERE WILL BE FOG TONIGHT ACROSS MUCH
OF THE REGION. THE HIGHEST POTENTIAL FOR DENSE FOG WILL BE IN
THE AFOREMENTIONED SNOW PACK REGION WHERE A LOW LEVEL INVERSION
SHOULD TRAP MUCH OF THIS MOISTURE NEAR THE SURFACE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 256 AM CDT SAT MAY 4 2013
FOR SUNDAY INTO MONDAY...THE MAIN QUESTION WILL BE WHETHER ANY
CONVECTION WILL CONTINUE TO DEVELOP ALONG THE STALLED OUT INVERTED
SURFACE TROUGH WHICH APPEARS TO SET UP ALONG THE MISSISSIPPI
RIVER. THE 04.00Z NAM/GFS WANT TO DEVELOP MORE PRECIPITATION ALONG
THIS FEATURE BUT STILL HAVE WAY TOO HIGH OF SURFACE DEW POINTS
ALONG IT AND SHOW TOO HIGH OF INSTABILITY WITH NO CAPPING AS A
RESULT. KEPT THE FORECAST DRY OVER THIS PERIOD...BUT WILL HAVE TO
WATCH FOR ANY TRENDS THERE IN THE SURFACE DEW POINTS.
OTHERWISE...THE CORE OF THE UPPER LEVEL LOW PROPAGATES TO THE
SOUTHEAST INTO THE MIDDLE OF NEXT WEEK WITH ANOTHER CUT OFF LOW
MEANDERING THROUGH THE ROCKIES. CONDITIONS SHOULD MAINLY BE DRY
INTO MID WEEK BEFORE THE TROUGH PUSHES BACK TO THE EAST.
PRECIPITATION CHANCES MAY BE A BIT OVERDONE FROM WEDNESDAY THROUGH
FRIDAY...BUT BOTH THE 04.00Z GFS AND ECMWF DEVELOP SHOWERS
THROUGHOUT THE PERIOD WITH THE LOW MOVING IN ALONG WITH A COLD
FRONT DROPPING DOWN FROM CANADA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 654 AM CDT SAT MAY 4 2013
BUFKIT SOUNDINGS SHOW THAT THE LIFR/IFR DECK WILL GRADUALLY
BECOME MVFR BY EARLY THIS AFTERNOON. WITH THE DRY AIR JUST OF THE
EAST...KEPT THE IDEA THAT KLSE MAY EVEN BECOME VFR FOR THIS
AFTERNOON AND EVENING. WITH MANY OF THE SHOWERS EXITING THE AREA
AND THE MESO MODELS NOT SHOWING JUST SCATTERED SHOWERS THIS
AFTERNOON AND EVENING...KEPT THE PRECIPITATION OUT OF BOTH TAF
SITES.
FOR LATE TONIGHT...THE MAIN QUESTION IS WHETHER DENSE FOG WILL
DEVELOP. WITH LIGHT SURFACE WINDS AND SNOW MELT ACROSS SOUTHEAST
MINNESOTA AND NORTHEAST IOWA...THERE IS A CONCERN THAT DENSE FOG
MAY DEVELOP. HOWEVER WITH THE WINDS ABOVE THE SURFACE AROUND
10 KNOTS AND THE POTENTIAL THAT SOME OF MOISTURE COULD GET INTO
THE SOIL...IT IS NOT A GIVEN. AS A RESULT...JUST LOWERED THE CEILINGS
AND ADDED SOME FOG TO THE FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
359 PM EDT SAT MAY 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM EDT SAT MAY 4 2013
AFTER BEING IN AN UNSETTLED WEATHER PATTERN FOR THE LAST SEVERAL
DAYS...THE AREA WILL TREND TOWARDS A DRIER PERIOD. WITH THE CUTOFF
LOW IS WELL TO OUR SOUTH AND THE NORTHERN STREAM JET FOCUSING
WELL NORTH INTO CANADA...THE AREA IS UNDER INCREASING UPPER LEVEL
RIDGING FROM THE RIDGE THAT HAS BEEN OVER EASTERN NORTH AMERICA.
THIS RIDGING...ALONG WITH SURFACE HIGH PRESSURE BUILDING OVER THE
UPPER GREAT LAKES WILL LEAD TO A DRIER AND WARMING TREND FOR THIS
WEEKEND.
THE FINAL PUSH FOR CENTRAL UPPER MICHIGAN IS CURRENTLY MOVING NNW
THIS MORNING AS THE 925MB WARM AIR ADVECTION SLOWLY PUSHES WEST.
FARTHER TO THE EAST...DRY MID LEVEL AIR SHOWN ON RAP ANALYSIS HAS
LED TO CLEAR SKIES OVER FAR EASTERN UPPER MICHIGAN ALONG THE
STALLED WARM FRONT AND ONLY MID TO HIGH CLOUDS OVER LAKE MICHIGAN
AND SOUTH CENTRAL UPPER MICHIGAN. LIGHT RAIN AND FREEZING RAIN IS
OCCURRING OVER THE FAR WEST...ALTHOUGH OBS AND RADAR ARE INDICATING
IT TO BE FAIRLY PATCHY. THERE ARE SOME STRONGER SHOWERS IN
SOUTHWEST WISCONSIN AND NORTHEAST IOWA...ASSOCIATED WITH SHORTWAVE
ENERGY PUSHING NORTHWEST THROUGH SOUTHWEST WISCONSIN AND THIS COULD
END UP BRUSHING THE FAR WESTERN CWA DURING THE AFTERNOON.
OTHERWISE...THE LIGHT PRECIPITATION OVER THE WEST WILL SLOWLY PUSH
OVER WESTERN LAKE SUPERIOR THROUGH THE DAY AND FALL AS RAIN WITH
THE 900-875MB TEMPS AROUND 8-9C. WITH LIGHT RAIN STILL OVER THE FAR
WEST AND TEMPERATURES BELOW FREEZING...WILL KEEP THE WINTER WEATHER
ADVISORY GOING UNTIL 12Z. ALL OF THE MODELS HAVE TEMPERATURES SLOWLY
RISING TO FREEZING OVER THE FAR WEST AT THAT TIME AND THEN SLOWLY
RISING ABOVE THAT AFTER SUNRISE. OTHERWISE...WITH THE LOW
LEVEL...SUB 900MB...NORTHEAST FLOW OVER THE WEST WILL KEEP THE LOW
CLOUDS IN PLACE THROUGH THE DAY.
THE DRIER AIR ALOFT SHOULD LEAD TO A DRY DAY ACROSS THE REST OF THE
CWA AND THE MAIN INFLUENCE ON THE WEATHER WILL BE THE LOCATION AND
DISSIPATION OF THE LOW CLOUDS OVER CENTRAL UPPER MICHIGAN. LATEST
TRENDS IN THE MODELS SHOW THAT THE LOW CLOUDS SHOULD DIMINISH
AROUND NOON OVER THE NORTH CENTRAL CWA. WITH THE EXPECTED LIGHT
NORTHERLY FLOW IN THE LOW LEVELS...NOT COMPLETELY CONFIDENT ON THAT
TIMING...SO ONLY WENT WITH PARTLY CLOUDY SKIES TOWARDS AFTERNOON.
BUT THE DRIER LOW LEVEL AIR TO THE SOUTHEAST...WONDERING IF THE
MODELS HAVE A HANDLE ON THE CLEARING IDEA AND THE FORECAST IS TOO
PESSIMISTIC. OTHERWISE...WOULD EXPECT MID-HIGH CLOUDS STREAMING
NORTHEAST ACROSS THE CENTRAL/EASTERN CWA THROUGH MUCH OF THE DAY.
AS FOR TEMPERATURES...EXPECT VALUES TO STRUGGLE TO REACH 40 OVER
THE FAR WEST UNDER THE CLOUDS. WITH THE BREAKS IN THE CLOUDS
OVER THE SOUTH CENTRAL AND EAST AND THE EXPECTED WESTWARD PUSH OF
THE 925/850MB TROUGH EARLY THIS MORNING AND THROUGH THE DAY ALLOWING
SOUTH-SOUTHEASTERLY FLOW TO DEVELOP OVER THE AREA...WOULD EXPECT
TEMPERATURES UNDER THE MAY SUN TO QUICKLY WARM INTO THE 50S/60S AND
A FEW LOWER 70S TOWARDS NEWBERRY. AS AN EXAMPLE...YESTERDAY WHERE
THE BREAKS IN THE CLOUDS WERE OVER THE EASTERN CWA...TEMPERATURES
WERE IN THE 50S AND LOWER 60S /DELTA...SCHOOLCRAFT...LUCE
COUNTIES/...BUT JUST TO THE WEST IN MARQUETTE COUNTY TEMPERATURES
WERE INN THE 30S. THUS...PINNING DOWN THE LOCATION/DISSIPATION OF
THE LOW CLOUDS CREATES A HUGE BUST POTENTIAL FOR HIGHS OVER THE
NORTH CENTRAL. NEAR LAKE SUPERIOR IN MARQUETTE COUNTY...THE NEAR
SURFACE FLOW WILL BE LIGHT AND NORTHERLY...WHICH WILL TRY TO KEEP
THE TEMPERATURES LOWER DUE TO LAKE SUPERIOR.
TONIGHT...HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA...WHILE THE
925/850MB TROUGH DISSIPATES OVER EASTERN MINNESOTA AND FAR WESTERN
LAKE SUPERIOR. THIS SHOULD LEAD TO A DRY NIGHT ACROSS MUCH OF THE
AREA AND LIKE TODAY...THE CLOUDS WILL BE ONE OF THE MAIN FORECAST
CONCERNS. MODELS SHOWING THE LOW CLOUDS REMAINING OVER THE FAR WEST
WITH THE LINGERING NORTHEASTERLY FLOW THROUGH THE NIGHT. EXPECT THAT
TO BE THE CASE AND WILL KEEP CLOUDY SKIES THERE. IN
ADDITION...THERE MAY BE SOME LIGHT DRIZZLE/RAIN OVER THE FAR WEST
WITH THE LOW CLOUDS IN THE EVENING...BUT OVERALL MUCH OF THE
PRECIPITATION SHOULD HAVE DIMINISHED WITH THE WEAKENING FORCING OVER
THE WESTERN LAKE. THE SLIGHTLY UPSLOPE NORTHEAST FLOW OVER THE
WEST...HAVE ADDED A MENTION OF PATCHY FOG DUE TO THE LOW
CLOUDS INTERACTING WITH THE HIGHER TERRAIN.
OVER THE NORTH CENTRAL...MODELS ARE SHOWING THE LOWER CLOUDS
REDEVELOPING TONIGHT WITH THE LIGHT NORTHERLY FLOW AND LINGERING LOW
LEVEL MOISTURE. WILL GO WITH A PARTLY-MOSTLY CLOUDY SKY AND THEN
DIMINISH IT HEADING SOUTH TOWARDS IRON MOUNTAIN. ALSO ADDED A
MENTION OF FOG TO THE HIGHER TERRAIN LOCATIONS.
FARTHER EAST AND AWAY FROM LAKE SUPERIOR...EXPECT MOSTLY CLEAR
SKIES WITH A SLIM POTENTIAL FOR FOG DUE TO THE EXPECTED MIXING OUT
TODAY AND DRIER AIR IN PLACE. THE FOG POTENTIAL WILL LIKELY DEPEND
ON IF FOG DEVELOPS OVER EASTERN LAKE SUPERIOR TODAY. IF IT
DOES...THE LIGHT NORTHERLY WINDS WILL DRAG IT SOUTH INTO THE
EASTERN CWA. DON/T HAVE THE CONFIDENCE TO ADD AT THIS POINT AND IT
WILL BE SOMETHING FOR THE DAY SHIFT TO WATCH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 416 AM EDT SAT MAY 4 2013
SUN...SFC HI PRES SINKING SLOWLY S FM ONTARIO WL SHIFT OVER LK SUP
BY LATE IN THE DAY UNDER UPR RDG AXIS TO THE N OF CLOSED LO SHIFTING
INTO THE SE CONUS. WITH THE ARRIVAL OF MORE ACYC FLOW/FRONTOLYSIS OF
LINGERING STNRY FNT AS WELL AS DIRUNAL HEATING...EXPECT MRNG LO CLDS
OVER THE NCENTRAL AND W TO SLOWLY DSPT. THESE CLDS WL BE MOST
PERSISTENT OVER THE HIER TERRAIN OF THE W WHERE LLVL MSTR IS A BIT
GREATER AND HOLD DOWN MAX TEMP RECOVERY WITH LLVL N WIND OFF LK SUP.
WL TEND TOWARD THE LOWER END OF GUIDANCE FOR TEMPS OVER THE NCENTRAL
AND W. MORE SUNSHINE OVER THE SCENTRAL AND E WITH H85 TEMPS UP TO
8-9C SHOULD ALLOW A SHARP CONTRAST TO THIS COOLER WX. EXPECT MAX
TEMPS UP TO 70 PER MIXING TO H85 ON FCST SDNGS AWAY FM THE LK
BREEZES THAT WL FORM IN PRESENCE OF WEAK GRADIENT ASSOCIATED WITH
THE HI.
SUN NGT THRU TUE...EXPECT DRY WX TO PREVAIL WITH NEAR STNRY HI PRES
UNDER UPR RDG AXIS EXTENDING E-W ACRS THE UPR LKS. ALTHOUGH H85
TEMPS ARE FCST TO REMAIN NEAR 8C...EXPECT A SLOW WARMING TREND AS
THE LLVLS SLOWLY MODERATE WITH HI SOLAR ANGLE. BUT WEAK PRES
GRADIENT UNDER THE SFC HI WL ALLOW LK BREEZES TO DVLP AND KEEP LK
SHORE COMMUNITIES COOLER. SOME MODELS GENERATE LGT QPF DURING THE
AFTNS WITH THE DAYTIME HEATING/LK BREEZE BNDRYS/LINGERING LLVL
MSTR...BUT WL NOT INCLUDE POPS ATTM GIVEN LARGE SCALE ACYC FLOW.
SUSPECT THERE WL BE QUITE A BIT OF DIURNAL CU. ALTHOUGH LGT WINDS WL
ALLOW FOR EFFICIENT RADIATIONAL COOLING...FCST PWATS REMAIN FAIRLY
HI ESPECIALLY OVER THE NW HALF. THE SHARPEST DIURNAL TEMP FALLS AT
NGT SHOULD BE OVER THE SCENTRAL AND E CLOSER TO THE CORE OF DRIER
AIR. OPTED TO INCLUDE A MENTION OF PATCHY FOG OVER THE INTERIOR WITH
THE LGT WINDS/FAIRLY SUBSTANTIAL LLVL MSTR.
TUE NGT INTO THU...APRCH OF WEAK SHRTWV FM THE W THAT WEAKENS RDG
OVER THE UPR LKS AND APRCH OF COLD FNT DROPPING S THRU ONTARIO ON
THE SRN FLANK OF DEEPENING UPR TROF CENTERED OVER HUDSON BAY WL
ALLOW A RETURN OF SOME -SHRA. SUSPECT THE BEST CHC FOR THESE SHRA WL
BE DURING THE DAY ON WED...WHEN DIURNAL HEATING WL BE IN PHASE WITH
DYNAMICS AHEAD OF THE APRCHG SHRTWV.
LATER THU THRU FRI...EXPECT A COOLING/DRYING TREND WITH N-NE WIND ON
THE SRN FLANK OF HI PRES BLDG INTO/THRU ONTARIO AND FCST H85 TEMPS
NEAR 0C BY FRI UNDER SLOWLY DEEPENING UPR TROF ACRS THE E HALF OF
NAMERICA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 151 PM EDT SAT MAY 4 2013
THE THICK DECK OF LOW CLOUDS SET UP OVER FAR WESTERN UPPER MI
CONTINUES TO EXIT EASTWARD...THANKS TO DRIER AIR AND DAYTIME
HEATING. EXPECT THE LOW CLOUDS AND FOG TO DEVELOP ONCE AGAIN TONIGHT
/NEARING IFR/...PARTICULARLY WHERE LOW LEVEL MOISTURE REMAINS
HIGH...OVER THE WESTERN TAF SITE OF IWD. LIGHT WINDS WILL BE THE
RULE AS A LARGE AREA OF HIGH PRESSURE SINKS IN FROM CENTRAL
ONTARIO...AND RESIDES OVER THE AREA BY MID AFTERNOON SUNDAY. MAINLY
DRY WEATHER /ALTHOUGH WITH PLENTY OF CLOUDS/ AND EARLY MORNING LAKE
BREEZES WILL BE COMMON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 AM EDT SAT MAY 4 2013
EXPECT N WINDS UP TO 20 KTS EARLY THIS MORNING TO DIMINISH THRU
TODAY/TONIGHT WITH APPROACH OF HI PRES FROM NW ONTARIO. WINDS WILL
THEN REMAIN LIGHT THRU NEXT WED WITH HI PRES/WEAK PRES GRADIENT
DOMINATING THE UPPER GREAT LAKES.
&&
.HYDROLOGY...
ISSUED AT 416 AM EDT SAT MAY 4 2013
THE STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER
AROUND WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL
REMAIN CONCERNS INTO AT LEAST EARLY NEXT WEEK...AND IN THE CASE OF
THE MICHIGAMME RIVER PERHAPS WELL INTO THE COMING WEEK. BUT
OTHERWISE RIVER LEVELS CONTINUE TO COME DOWN DESPITE SOME RECENT
HEAVY PRECIP THAT IMPACTED MAINLY THE W HALF OF UPR MI. IN FACT...A
DECENT AMOUNT OF WATER EQUIVALENT HAS OCCURRED SINCE THU OVER THE
WESTERN CWA...VCNTY OF IRONWOOD TO ONTONAGON...WITH OVER 2 INCHES
OVER FAR WESTERN GOGEBIC COUNTY. WILL HAVE TO ASSESS WHAT AFFECT THE
PRECIP WILL HAVE WHEN COMBINED WITH FURTHER MELTING OF ANY SUSTAINED
SNOWPACK WHEN TEMPS WARM SUN INTO NEXT WEEK. SNOW WATER EQUIVALENT
OF 8.8 INCHES IN PAINESDALE IN HOUGHTON COUNTY ON THURSDAY WITH 24
INCHES OF SNOW DEPTH...SO THE OTTER RIVER STILL HAS PLENTY OF SNOW
IN THE HEADWATERS WHICH MAY CAUSE ADDITIONAL PROBELMS AT CLLM4 IN
THE COMING DAYS.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...KF
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
151 PM EDT SAT MAY 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM EDT SAT MAY 4 2013
AFTER BEING IN AN UNSETTLED WEATHER PATTERN FOR THE LAST SEVERAL
DAYS...THE AREA WILL TREND TOWARDS A DRIER PERIOD. WITH THE CUTOFF
LOW IS WELL TO OUR SOUTH AND THE NORTHERN STREAM JET FOCUSING
WELL NORTH INTO CANADA...THE AREA IS UNDER INCREASING UPPER LEVEL
RIDGING FROM THE RIDGE THAT HAS BEEN OVER EASTERN NORTH AMERICA.
THIS RIDGING...ALONG WITH SURFACE HIGH PRESSURE BUILDING OVER THE
UPPER GREAT LAKES WILL LEAD TO A DRIER AND WARMING TREND FOR THIS
WEEKEND.
THE FINAL PUSH FOR CENTRAL UPPER MICHIGAN IS CURRENTLY MOVING NNW
THIS MORNING AS THE 925MB WARM AIR ADVECTION SLOWLY PUSHES WEST.
FARTHER TO THE EAST...DRY MID LEVEL AIR SHOWN ON RAP ANALYSIS HAS
LED TO CLEAR SKIES OVER FAR EASTERN UPPER MICHIGAN ALONG THE
STALLED WARM FRONT AND ONLY MID TO HIGH CLOUDS OVER LAKE MICHIGAN
AND SOUTH CENTRAL UPPER MICHIGAN. LIGHT RAIN AND FREEZING RAIN IS
OCCURRING OVER THE FAR WEST...ALTHOUGH OBS AND RADAR ARE INDICATING
IT TO BE FAIRLY PATCHY. THERE ARE SOME STRONGER SHOWERS IN
SOUTHWEST WISCONSIN AND NORTHEAST IOWA...ASSOCIATED WITH SHORTWAVE
ENERGY PUSHING NORTHWEST THROUGH SOUTHWEST WISCONSIN AND THIS COULD
END UP BRUSHING THE FAR WESTERN CWA DURING THE AFTERNOON.
OTHERWISE...THE LIGHT PRECIPITATION OVER THE WEST WILL SLOWLY PUSH
OVER WESTERN LAKE SUPERIOR THROUGH THE DAY AND FALL AS RAIN WITH
THE 900-875MB TEMPS AROUND 8-9C. WITH LIGHT RAIN STILL OVER THE FAR
WEST AND TEMPERATURES BELOW FREEZING...WILL KEEP THE WINTER WEATHER
ADVISORY GOING UNTIL 12Z. ALL OF THE MODELS HAVE TEMPERATURES SLOWLY
RISING TO FREEZING OVER THE FAR WEST AT THAT TIME AND THEN SLOWLY
RISING ABOVE THAT AFTER SUNRISE. OTHERWISE...WITH THE LOW
LEVEL...SUB 900MB...NORTHEAST FLOW OVER THE WEST WILL KEEP THE LOW
CLOUDS IN PLACE THROUGH THE DAY.
THE DRIER AIR ALOFT SHOULD LEAD TO A DRY DAY ACROSS THE REST OF THE
CWA AND THE MAIN INFLUENCE ON THE WEATHER WILL BE THE LOCATION AND
DISSIPATION OF THE LOW CLOUDS OVER CENTRAL UPPER MICHIGAN. LATEST
TRENDS IN THE MODELS SHOW THAT THE LOW CLOUDS SHOULD DIMINISH
AROUND NOON OVER THE NORTH CENTRAL CWA. WITH THE EXPECTED LIGHT
NORTHERLY FLOW IN THE LOW LEVELS...NOT COMPLETELY CONFIDENT ON THAT
TIMING...SO ONLY WENT WITH PARTLY CLOUDY SKIES TOWARDS AFTERNOON.
BUT THE DRIER LOW LEVEL AIR TO THE SOUTHEAST...WONDERING IF THE
MODELS HAVE A HANDLE ON THE CLEARING IDEA AND THE FORECAST IS TOO
PESSIMISTIC. OTHERWISE...WOULD EXPECT MID-HIGH CLOUDS STREAMING
NORTHEAST ACROSS THE CENTRAL/EASTERN CWA THROUGH MUCH OF THE DAY.
AS FOR TEMPERATURES...EXPECT VALUES TO STRUGGLE TO REACH 40 OVER
THE FAR WEST UNDER THE CLOUDS. WITH THE BREAKS IN THE CLOUDS
OVER THE SOUTH CENTRAL AND EAST AND THE EXPECTED WESTWARD PUSH OF
THE 925/850MB TROUGH EARLY THIS MORNING AND THROUGH THE DAY ALLOWING
SOUTH-SOUTHEASTERLY FLOW TO DEVELOP OVER THE AREA...WOULD EXPECT
TEMPERATURES UNDER THE MAY SUN TO QUICKLY WARM INTO THE 50S/60S AND
A FEW LOWER 70S TOWARDS NEWBERRY. AS AN EXAMPLE...YESTERDAY WHERE
THE BREAKS IN THE CLOUDS WERE OVER THE EASTERN CWA...TEMPERATURES
WERE IN THE 50S AND LOWER 60S /DELTA...SCHOOLCRAFT...LUCE
COUNTIES/...BUT JUST TO THE WEST IN MARQUETTE COUNTY TEMPERATURES
WERE INN THE 30S. THUS...PINNING DOWN THE LOCATION/DISSIPATION OF
THE LOW CLOUDS CREATES A HUGE BUST POTENTIAL FOR HIGHS OVER THE
NORTH CENTRAL. NEAR LAKE SUPERIOR IN MARQUETTE COUNTY...THE NEAR
SURFACE FLOW WILL BE LIGHT AND NORTHERLY...WHICH WILL TRY TO KEEP
THE TEMPERATURES LOWER DUE TO LAKE SUPERIOR.
TONIGHT...HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA...WHILE THE
925/850MB TROUGH DISSIPATES OVER EASTERN MINNESOTA AND FAR WESTERN
LAKE SUPERIOR. THIS SHOULD LEAD TO A DRY NIGHT ACROSS MUCH OF THE
AREA AND LIKE TODAY...THE CLOUDS WILL BE ONE OF THE MAIN FORECAST
CONCERNS. MODELS SHOWING THE LOW CLOUDS REMAINING OVER THE FAR WEST
WITH THE LINGERING NORTHEASTERLY FLOW THROUGH THE NIGHT. EXPECT THAT
TO BE THE CASE AND WILL KEEP CLOUDY SKIES THERE. IN
ADDITION...THERE MAY BE SOME LIGHT DRIZZLE/RAIN OVER THE FAR WEST
WITH THE LOW CLOUDS IN THE EVENING...BUT OVERALL MUCH OF THE
PRECIPITATION SHOULD HAVE DIMINISHED WITH THE WEAKENING FORCING OVER
THE WESTERN LAKE. THE SLIGHTLY UPSLOPE NORTHEAST FLOW OVER THE
WEST...HAVE ADDED A MENTION OF PATCHY FOG DUE TO THE LOW
CLOUDS INTERACTING WITH THE HIGHER TERRAIN.
OVER THE NORTH CENTRAL...MODELS ARE SHOWING THE LOWER CLOUDS
REDEVELOPING TONIGHT WITH THE LIGHT NORTHERLY FLOW AND LINGERING LOW
LEVEL MOISTURE. WILL GO WITH A PARTLY-MOSTLY CLOUDY SKY AND THEN
DIMINISH IT HEADING SOUTH TOWARDS IRON MOUNTAIN. ALSO ADDED A
MENTION OF FOG TO THE HIGHER TERRAIN LOCATIONS.
FARTHER EAST AND AWAY FROM LAKE SUPERIOR...EXPECT MOSTLY CLEAR
SKIES WITH A SLIM POTENTIAL FOR FOG DUE TO THE EXPECTED MIXING OUT
TODAY AND DRIER AIR IN PLACE. THE FOG POTENTIAL WILL LIKELY DEPEND
ON IF FOG DEVELOPS OVER EASTERN LAKE SUPERIOR TODAY. IF IT
DOES...THE LIGHT NORTHERLY WINDS WILL DRAG IT SOUTH INTO THE
EASTERN CWA. DON/T HAVE THE CONFIDENCE TO ADD AT THIS POINT AND IT
WILL BE SOMETHING FOR THE DAY SHIFT TO WATCH.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 416 AM EDT SAT MAY 4 2013
SUN...SFC HI PRES SINKING SLOWLY S FM ONTARIO WL SHIFT OVER LK SUP
BY LATE IN THE DAY UNDER UPR RDG AXIS TO THE N OF CLOSED LO SHIFTING
INTO THE SE CONUS. WITH THE ARRIVAL OF MORE ACYC FLOW/FRONTOLYSIS OF
LINGERING STNRY FNT AS WELL AS DIRUNAL HEATING...EXPECT MRNG LO CLDS
OVER THE NCENTRAL AND W TO SLOWLY DSPT. THESE CLDS WL BE MOST
PERSISTENT OVER THE HIER TERRAIN OF THE W WHERE LLVL MSTR IS A BIT
GREATER AND HOLD DOWN MAX TEMP RECOVERY WITH LLVL N WIND OFF LK SUP.
WL TEND TOWARD THE LOWER END OF GUIDANCE FOR TEMPS OVER THE NCENTRAL
AND W. MORE SUNSHINE OVER THE SCENTRAL AND E WITH H85 TEMPS UP TO
8-9C SHOULD ALLOW A SHARP CONTRAST TO THIS COOLER WX. EXPECT MAX
TEMPS UP TO 70 PER MIXING TO H85 ON FCST SDNGS AWAY FM THE LK
BREEZES THAT WL FORM IN PRESENCE OF WEAK GRADIENT ASSOCIATED WITH
THE HI.
SUN NGT THRU TUE...EXPECT DRY WX TO PREVAIL WITH NEAR STNRY HI PRES
UNDER UPR RDG AXIS EXTENDING E-W ACRS THE UPR LKS. ALTHOUGH H85
TEMPS ARE FCST TO REMAIN NEAR 8C...EXPECT A SLOW WARMING TREND AS
THE LLVLS SLOWLY MODERATE WITH HI SOLAR ANGLE. BUT WEAK PRES
GRADIENT UNDER THE SFC HI WL ALLOW LK BREEZES TO DVLP AND KEEP LK
SHORE COMMUNITIES COOLER. SOME MODELS GENERATE LGT QPF DURING THE
AFTNS WITH THE DAYTIME HEATING/LK BREEZE BNDRYS/LINGERING LLVL
MSTR...BUT WL NOT INCLUDE POPS ATTM GIVEN LARGE SCALE ACYC FLOW.
SUSPECT THERE WL BE QUITE A BIT OF DIURNAL CU. ALTHOUGH LGT WINDS WL
ALLOW FOR EFFICIENT RADIATIONAL COOLING...FCST PWATS REMAIN FAIRLY
HI ESPECIALLY OVER THE NW HALF. THE SHARPEST DIURNAL TEMP FALLS AT
NGT SHOULD BE OVER THE SCENTRAL AND E CLOSER TO THE CORE OF DRIER
AIR. OPTED TO INCLUDE A MENTION OF PATCHY FOG OVER THE INTERIOR WITH
THE LGT WINDS/FAIRLY SUBSTANTIAL LLVL MSTR.
TUE NGT INTO THU...APRCH OF WEAK SHRTWV FM THE W THAT WEAKENS RDG
OVER THE UPR LKS AND APRCH OF COLD FNT DROPPING S THRU ONTARIO ON
THE SRN FLANK OF DEEPENING UPR TROF CENTERED OVER HUDSON BAY WL
ALLOW A RETURN OF SOME -SHRA. SUSPECT THE BEST CHC FOR THESE SHRA WL
BE DURING THE DAY ON WED...WHEN DIURNAL HEATING WL BE IN PHASE WITH
DYNAMICS AHEAD OF THE APRCHG SHRTWV.
LATER THU THRU FRI...EXPECT A COOLING/DRYING TREND WITH N-NE WIND ON
THE SRN FLANK OF HI PRES BLDG INTO/THRU ONTARIO AND FCST H85 TEMPS
NEAR 0C BY FRI UNDER SLOWLY DEEPENING UPR TROF ACRS THE E HALF OF
NAMERICA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 151 PM EDT SAT MAY 4 2013
THE THICK DECK OF LOW CLOUDS SET UP OVER FAR WESTERN UPPER MI
CONTINUES TO EXIT EASTWARD...THANKS TO DRIER AIR AND DAYTIME
HEATING. EXPECT THE LOW CLOUDS AND FOG TO DEVELOP ONCE AGAIN TONIGHT
/NEARING IFR/...PARTICULARLY WHERE LOW LEVEL MOISTURE REMAINS
HIGH...OVER THE WESTERN TAF SITE OF IWD. LIGHT WINDS WILL BE THE
RULE AS A LARGE AREA OF HIGH PRESSURE SINKS IN FROM CENTRAL
ONTARIO...AND RESIDES OVER THE AREA BY MID AFTERNOON SUNDAY. MAINLY
DRY WEATHER /ALTHOUGH WITH PLENTY OF CLOUDS/ AND EARLY MORNING LAKE
BREEZES WILL BE COMMON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 AM EDT SAT MAY 4 2013
EXPECT N WINDS UP TO 20 KTS EARLY THIS MORNING TO DIMINISH THRU
TODAY/TONIGHT WITH APPROACH OF HI PRES FROM NW ONTARIO. WINDS WILL
THEN REMAIN LIGHT THRU NEXT WED WITH HI PRES/WEAK PRES GRADIENT
DOMINATING THE UPPER GREAT LAKES.
&&
.HYDROLOGY...
ISSUED AT 416 AM EDT SAT MAY 4 2013
THE STURGEON RIVER AT ALSTON AND CHASSELL...THE MICHIGAMME RIVER
AROUND WITCH LAKE...AND THE PAINT RIVER NEAR CRYSTAL FALLS WILL
REMAIN CONCERNS INTO AT LEAST EARLY NEXT WEEK...AND IN THE CASE OF
THE MICHIGAMME RIVER PERHAPS WELL INTO THE COMING WEEK. BUT
OTHERWISE RIVER LEVELS CONTINUE TO COME DOWN DESPITE SOME RECENT
HEAVY PRECIP THAT IMPACTED MAINLY THE W HALF OF UPR MI. IN FACT...A
DECENT AMOUNT OF WATER EQUIVALENT HAS OCCURRED SINCE THU OVER THE
WESTERN CWA...VCNTY OF IRONWOOD TO ONTONAGON...WITH OVER 2 INCHES
OVER FAR WESTERN GOGEBIC COUNTY. WILL HAVE TO ASSESS WHAT AFFECT THE
PRECIP WILL HAVE WHEN COMBINED WITH FURTHER MELTING OF ANY SUSTAINED
SNOWPACK WHEN TEMPS WARM SUN INTO NEXT WEEK. SNOW WATER EQUIVALENT
OF 8.8 INCHES IN PAINESDALE IN HOUGHTON COUNTY ON THURSDAY WITH 24
INCHES OF SNOW DEPTH...SO THE OTTER RIVER STILL HAS PLENTY OF SNOW
IN THE HEADWATERS WHICH MAY CAUSE ADDITIONAL PROBELMS AT CLLM4 IN
THE COMING DAYS.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...KF
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
355 PM CDT SAT MAY 4 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 341 PM CDT SAT MAY 4 2013
WARMER WEATHER WILL GRADUALLY MOVE IN ACROSS THE REGION OVER THE
NEXT FEW DAYS AND CONDITIONS BEGIN TO DRY OUT. BY THE MIDDLE OF THE
WEEK A SERIES OF UPPER LEVEL DISTURBANCES WILL BRING RETURNED
CHANCES FOR SHOWERS AND THUNDERSTORMS...ALONG WITH COOLER
TEMPERATURES.
EARLY AFTERNOON NORTH AMERICAN WATER VAPOR IMAGERY TOGETHER WITH
500MB HEIGHTS AND WINDS SHOWED THE CUTOFF LOW SPINNING OVER THE
OZARK MOUNTAINS...WITH A RIDGE LOCATED ALONG EACH COAST. AT THE
SURFACE A LOOSE PRESSURE GRADIENT WAS DRAPED ACROSS THE UPPER
MIDWEST BETWEEN A 1028 HIGH IN NORTH DAKOTA...AND A 1013 LOW IN
SOUTHERN MISSOURI WITH NORTHERLY WINDS OVER MINNESOTA AND
WISCONSIN. THE EXPANSIVE CLOUD SHIELD FROM THE AFOREMENTIONED
UPPER LEVEL LOW WAS BEGINNING TO SHOW SOME HOLES IN
WISCONSIN...AND THIS ALLOWED TEMPERATURES TO CLIMB INTO THE MID
70S WHERE THERE WAS NO SNOWPACK. HOWEVER...FARTHER WEST
TEMPERATURES WERE ONLY IN THE 40S WHERE THE DEEP SNOWPACK LINGERED
FROM THE PREVIOUS WINTER STORM. FARTHER WEST STILL IN NEAR THE
SD/MN BORDER TEMPERATURES WERE ONLY IN THE UPPER 30S ALONG WITH
THICKER CLOUDS AND LIGHT DRIZZLE ASSOCIATED WITH THE DEFORMATION
ZONE FROM THE DECAYING CYCLONE TO THE SOUTH. TONIGHT FORECAST
MODELS SHOW THE PRESSURE GRADIENT RELAXING...RESULTING IN
DECREASING WINDS. AS THE CLEARING TREND PROGRESSES WESTWARD
OVERNIGHT AREAS OF FOG ARE EXPECTED TO DEVELOP ALONG THE MN/WI
BORDER...WITH THE HIGHEST POTENTIAL FOR DENSE FOG ALONG AND EAST
OF A LINE FROM ALBERT LEA UP THROUGH RED WING AND RICE LAKE WI.
FORECAST SOUNDINGS SHOW A DEEP INVERSION WITH LOW LEVEL
MOISTURE...BUT FEEL THE WINDS ARE OVERDONE...SO THE FOG POTENTIAL
IS HIGHER THAN INDICATED. MEMBER 2 OF THE HOPWRF HAS A BETTER
HANDLE OF THE CLEARING TREND...AND SHOWS FOG DEVELOPMENT IN THIS
REGION AROUND 08Z. THE 16Z RUN OF THE HRRR SHOWS A SIMILAR TREND.
THEREFORE HAVE ISSUED A DENSE FOG ADVISORY OVERNIGHT. HIGH
TEMPERATURES ON SUNDAY WILL DEPEND ON HOW QUICKLY WE CAN MIX OUT
THE FOG. THIS WILL BE DIFFICULT TO DO WITH LIGHT WINDS AND WEAK
MECHANICAL MIXING...SO WILL HAVE TO DEPEND ON THE EARLY MAY SUN.
TEMPERATURES ACROSS THE WEST WILL BE 15 TO 20 DEGREES COOLER THAN
SNOW FREE AREAS OF WISCONSIN DUE TO CLOUD COVER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 341 PM CDT SAT MAY 4 2013
SUNDAY NIGHT WILL HAVE ANOTHER FAVORABLE SETUP FOR FOG
DEVELOPMENT. ON MONDAY SURFACE TEMPERATURES WILL REBOUND TO NEAR
70 DEGREES...WITH WARMER TEMPS ON TUESDAY AS SOUTHERLY FLOW
INCREASES AHEAD OF THE NEXT WEAK UPPER LEVEL WAVE. USED A MIX DOWN
TOOL TO FORECAST HIGH TEMPERATURES...AND INCREASED THEM A FEW
DEGREES ABOVE THE PREVIOUS FORECAST...ESPECIALLY IN FAR WESTERN
MINNESOTA. THIS WAVE IS FORECAST TO BRING A CHANCE FOR SHOWERS AND
THUNDERSTORMS WEDNESDAY. THE SEVERE WEATHER THREAT IS VERY
LOW...WITH SMALL DEEP LAYER SHEAR AND ONLY 500J/KG OF MLCAPE.
UNSETTLED WEATHER WILL CONTINUE THROUGH THE END OF THE WEEK. LOW
POPS AND SLIGHTLY COOLER TEMPERATURES WILL BE FOCUSED ALONG A WARM
FRONT THAT IS FORECAST TO STALL OUT ACROSS THE REGION...AS
PERIODIC SHORTWAVES MOVING ACROSS THE UPPER MIDWEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT
1230 PM CDT SAT MAY 4 2013
HIGH PRESSURE OVER SOUTH CENTRAL CANADA IS STUCK IN PLACE AS AN
UPPER LEVEL LOW OVER SOUTHWEST MISSOURI SLOWLY DRIFTS TO CENTRAL
ALABAMA BY SUNDAY NIGHT. AS THE LOW DRIFTS SOUTHEAST CHANCES FOR
ANY PRECIPITATION WILL CONTINUE TO DECREASE. BY SUNDAY AFTERNOON
IFR CONDITIONS WILL TREND TO MVFR/VFR. THERE MAYBE A SPRINKLE OR
TWO AND SOME LIGHT DRIZZLE THIS AFTERNOON BUT NOT ENOUGH TO
MENTION IN THE TERMINALS. BETTER CHANCES FOR THE SPRINKLES
NORTH AND NORTHWEST OF KMSP. FOR KRNH/KEAU SATELLITE INDICATES
CLEARING OVER WESTERN WI. THAT MAY BE SHORT LIVED DUE TO THE VERY
WET GROUND AND COOL TEMPERATURES LEADING TO A SCT-BKN
DECK...REMAINING VFR CONDITIONS THOUGH. AT ANY RATE PLENTY OF LOW
LEVEL MOISTURE IN PLACE FOR FOG FORMATION RIGHT AFTER SUNSET
TONIGHT. SHOULD SEE A PERIOD OR TWO OF DRIZZLE AFTER MIDNIGHT.
EXPECT LIFR CIGS TO BE MORE PROMINENT OVER THE WI TERMINALS. MAY
SEE LIFR VISIBILITIES OVER THE WI TERMINALS TOO BUT NOT THAT
CONFIDENT TO ADD THEN AT THIS POINT IN TIME.
KMSP...
THE PRIMARY CONCERN IS THE THREAT OF DRIZZLE LATER TONIGHT AND
CLOSE TO LIFR CIGS. NO REASON TO SEE CURRENT CIGS INCREASE UNTIL
AFTER 13Z SUNDAY. MAY BE A PERIOD OR TWO OF LIFR AFTER 07Z. DO NOT
EXPECT IT TO PERSIST. NORTH- NORTHEAST WINDS /010-030/ WILL
PREVAIL THIS AFTERNOON AT SPEEDS OF 8 TO 12 KTS...THEN DECREASE TO AROUND
5-6KTS AFTER SUNSET AND REMAIN THAT WAY ALL DAY SUNDAY. CEILINGS
SHOULD RISE TO VFR BY 19Z AND MAYBE SCATTER OUT.
/OUTLOOK FOR KMSP/
MON...VFR. WINDS LIGHT/VARIABLE.
TUE...VFR. WINDS LIGHT/VARIABLE.
WED...VFR. WIND SOUTH AT 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR MNZ078-085-
093.
WI...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR WIZ015-016-
023>028.
&&
$$
SHORT TERM...JRB
LONG TERM...JRB
AVIATION...DRL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
344 PM CDT SAT MAY 4 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 342 PM CDT SAT MAY 4 2013
MAIN CHALLENGE FOR THIS FORECAST PACKAGE WILL BE PCPN. LATEST
ANALYSIS SHOWS UPPER LOW OVER NRN ARKANSAS. EXPECT SLOWER CHANGES TO
THE LOCAL WEATHER OVER THE NEXT FEW DAYS AS THE OVERALL PATTERN
SHOWS A REX BLOCK OVER WRN CONUS AND ANOTHER BLOCK OVER THE EAST
COAST.
MODELS INITIALIZED WELL AND AND OPTED FOR A BLENDED SOLN. FOR TODAY
AND TONIGHT...MAIN QUESTION IS WHERE AREA OF PCPN WILL SETTLE.
REGIONAL RADAR SHOWS BAND OF PCPN MOVING NORTH INTO WEST CENTRAL AND
NW MINNESOTA. HRRR AND RAP MODELS IN GENERAL AGREEMENT ON PLACEMENT
OF PCPN AND EXPECT MOST PCPN AMOUNTS WILL BE UNDER A QUARTER INCH
OVER THE NEXT 24 HOURS. THE 300K ISENTROPIC ANALYSIS SHOWS SOME
DECENT LIFT AND EXPECTING AN 850MB BAROCLINIC ZONE TO SET UP.
HOWEVER...CONDENSATION PRESSURE DEFICITS WEAK SO FOR NOW WILL ONLY
KEEP LIKELY POPS IN THAT AREA. FOR SUNDAY...LOOKING FOR THE
BAROCLINIC ZONE TO SLOWLY SLIDE SOUTHEAST AND WILL SEE THE END OF
PCPN. OTHERWISE...LOOKING FOR DRIER WEATHER GOING INTO MONDAY.
EXTENSIVE CLOUD COVER WILL KEEP TEMPERATURES A BIT LOWER TODAY
INTO SUNDAY WHEN THE UPPER RIDGE BEGINS SLIDE OVER THE AREA AND A
WARMING TREND BEGINS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 342 PM CDT SAT MAY 4 2013
12 UTC GFS/ECMWF SHOW THE FORECAST AREA IN POORLY DEFINED SPLIT FLOW
MID-WEEK...TRANSITIONING TO NORTHWEST FLOW ALOFT FRIDAY NIGHT INTO
SATURDAY WITH A STRONG CANADIAN COLD FRONT. PRECIPITATION CHANCES
THROUGH FRIDAY WILL DEPEND ON EVOLUTION OF A WEAK CUT-OFF LOW ACROSS
THE SOUTHERN ROCKIES. MOST MODELS PAINT MOST QPF ACROSS THE CENTRAL
PLAINS...BUT SOME DOES MAKE IT FARTHER NORTH. WITH THESE CUT-OFF
LOWS NOT A LOT OF CONFIDENCE...SO WILL KEEP ALL BLEND 20-40 POPS FOR
MOST OF THE WEEK. HOWEVER...THERE SHOULD BE MORE DRY PERIODS THAN
WET. WILL ALSO LIMIT THUNDER MENTION AS INSTABILITY APPEARS TO BE
MINIMAL AT THIS TIME. TEMPERATURES WILL BE ON THE WARM-SIDE OF THE
MOST RECENT THERMAL REGIME WITH HIGHS IN THE 60S AND LOWS MAINLY IN
THE 40S. IT DOES APPEAR CONDITIONS WILL COOL ON SATURDAY WITH
PASSAGE OF THE FRONT FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1258 PM CDT SAT MAY 4 2013
IFR/MVFR CEILINGS TO IMPACT KBJI THROUGH THE TAF PERIOD. MVFR
CEILINGS MAY CLIP KFAR/KTVF THIS AFTERNOON. FOR GFK/KDVL...EXPECT
VFR CONDITIONS. SOME LIGHT RAIN IS STILL POSSIBLE ACROSS NORTHWEST
MN...IMPACTING KBJI AND TO A LESSER EXTENT KTVF AND KFAR...BUT ANY
REDUCTION IN VISIBILITY WILL BE 3 MILES OR BETTER. WINDS WILL REMAIN
FROM THE NORTH-NORTHEAST AROUND 10 KTS...WITH OCCASIONAL AFTERNOON
GUSTS UP TO 20 KTS.
&&
.HYDROLOGY...
ISSUED AT 1258 PM CDT SAT MAY 4 2013
THE BROAD CREST WAVE OF SNOWMELT RUNOFF IS APPROACHING THE
DRAYTON AREA THIS WEEKEND WITH A CREST EXPECTED NEAR 40 FEET.
THE CREST WAVE WILL MOVE INTO THE PEMBINA REGION TOWARD THE END OF
NEXT WEEK WITH A FORECAST NEAR 48.5 FEET...JUST UNDER MAJOR FLOOD
STAGE. A SECOND ROUND OF RUNOFF IS EXPECTED ALONG THE PEMBINA RIVER
WITH ADDITIONAL RISES FORECAST AT WALHALLA AND NECHE THIS NEXT WEEK.
ELSEWHERE RIVERS CONTINUE TO RECEDE AS NO NEW RUNOFF IS OCCURRING
WITH THE DRY WEATHER OVER THE PAST WEEK.
AREAL FLOODING...WILL KEEP THE NORTH DAKOTA WARNINGS GOING AS
OVERLAND FLOODING CONTINUES TO CAUSE ISSUES AND ROAD CLOSURES. AS
FOR THE BELTRAMI AND CLEARWATER COUNTIES WILL CANCEL AFTER
CONFIRMING WITH COUNTY OFFICIALS THAT OVERLAND WATER HAS
DIMINISHED DRAMATICALLY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...HOPKINS
LONG TERM...ROGERS
AVIATION...ROGERS
HYDROLOGY...JK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
600 PM CDT SAT MAY 4 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 236 PM CDT SAT MAY 4 2013
AN UPPER LEVEL DISTURBANCE ROTATING AROUND THE UPPER LOW CAUSED
SOME SHOWERS TO DEVELOP LATE THIS MORNING/EARLY THIS AFTERNOON.
MOST OF THESE SHOWERS WERE NOW WEST OF WOOD AND MARATHON COUNTY.
COULD NOT RULE OUT A STRAY SHOWER UNTIL 21Z...BUT WILL NOT
HIGHLIGHT IN A PRE-FIRST PERIOD TO THE ZONE FORECAST TO ACCOUNT
FOR THIS REMOTE POSSIBILITY.
ATTENTION THEN TURNS TO THE FOG. NUMERICAL GUIDANCE NOT INDICATIVE
OF DENSE FOG LATE TONIGHT OUTSIDE THE FAR NORTH. HOWEVER...DEW POINTS
MAINLY IN THE 40S TO AROUND 50 THIS AFTERNOON...PARTLY CLOUDY SKIES
AND LIGHT WINDS TONIGHT...AND A COLDER THAN NORMAL SOIL TEMPERATURES
LEAD ME TO THINK THERE WILL BE MORE FOG/DENSE FOG AROUND TONIGHT THAN
THE NUMERICAL GUIDANCE SUGGEST. WILL MENTION AREAS OF DENSE FOG ACROSS
THE FAR NORTH AND AREAS OF FOG WITH LOCALLY DENSE FOG POSSIBLE ELSEWHERE.
ANY FOG SHOULD BURN OFF BY MID MORNING ON SUNDAY. ANOTHER MILD DAY
IS EXPECTED WITH HIGHS WELL INTO THE 60S TO LOWER 70S. A WEAK BOUNDARY
IS EXPECTED TO DROP SOUTH IN NORTHERN WISCONSIN SUNDAY AFTERNOON. THIS
BOUNDARY COULD TRIGGER SOME ISOLATED/SCATTERED SHOWERS GENERALLY NORTH
OF A WAUSAU TO WAUSAUKEE LINE.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 236 PM CDT SAT MAY 4 2013
THE REMNANTS OF THE SYSTEM WHICH CAUSED HAVOC OVER THE MID SECTION
OF THE COUNTRY THE LATER HALF OF THE PREVIOUS WORK WEEK CONTINUES
TO CHURN OVER THE SOUTHEAST STATES AND SLOWLY WEAKEN THROUGH
TUESDAY. ANOTHER UPPER LOW SYSTEM IS PROGGED TO DROP INTO SOUTHWEST
STATES EARLY IN THE NEW WORK WEEK AS WELL.
LOCALLY A RIDGE OF HIGH PRESSURE WILL EXTEND OVER THE GREAT LAKES
REGION TROUGH AT LEAST MID WEEK. ABOVE NORMAL AND MAINLY DRY
CONDITIONS CAN BE EXPECTED THROUGH MID WEEK. WEAK MID LEVEL
CONVERGENCE OVER THE NORTHERN PLAINS AND NORTHWEST WESTERN MAY BE
CLOSE ENOUGH TO PARTS OF NORTH CENTRAL AND CENTRAL WISCONSIN TO
GENERATE AN ISOLATED SHOWER IN THE AFTERNOON EACH MONDAY AND
TUESDAY SINCE MARGINAL INSTABILITY REMAINS IN THIS AREA. SLIGHTLY
COOLER TEMPS ALOFT WERE PRODUCING TOTAL TOTALS IN THE MID TO UPPER
40S. HOWEVER SUBSIDENCE FROM THE EAST WINDS WITH THE UPPER RIDGE
MAY LOWER HUMIDITY TO KEEP THE SHOWERS IN CHECK. AS A RESULT WILL
KEEP THE FORECAST DRY THROUGH MID WEEK.
PROGS BEGIN TO INTRODUCE A PATTERN CHANGE WITH LIFTING THE
SOUTHWEST U.S. LOW INTO THE MID SECTION OF THE COUNTRY BEFORE
DEVELOPING A DEEPER SHORT WAVE TROUGH THE LATER HALF OF THE WEEK.
PCPN CHANCES WILL BE ON THE INCREASE OVER AT LEAST THE SOUTH HALF
OF THE STATE AS THE TROUGH DRAGS A LOW PRESSURE SYSTEM OVER IOWA
AND ILLINOIS WHILE HIGH PRESSURE DROPS INTO THE GREAT LAKES FROM
THE NORTH. A COLDER SURGE OF AIR WITH A FROPA MAY DROP INTO THE
REGION LATE SATURDAY INTO SATURDAY NIGHT. A FEW RAIN/SNOW? SHOWERS
WILL BE POSSIBLE ACROSS NORTH NEXT WEEKEND.
THE RIDGE OF HIGH PRESSURE WITH LIGHT WINDS AND CLEAR SKIES MAY
PROVIDE A FEW NIGHTS WITH FOG.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 557 PM CDT SAT MAY 4 2013
MAIN ISSUE IS THE POTENTIAL FOR FG FORMATION TNGT. RAP VSBY FCST
FOCUSES ON THE FAR N...WHERE THERE IS STILL SOME LINGERING
SNOW/ICE COVER...AND HAS MVFR CONDITIONS ELSEWHERE. THAT/S SIMILAR
TO WHAT/S IN THE GOING FCST...SO WL STAY THE COURSE WITH THAT FOR
NOW AND SEE HOW DPWTS REACT THIS EVENING. /PARTS OF CENTRAL WI
MIXED INTO DRIER AIR ALOFT THIS AFTN./
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....ECKBERG
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
306 PM CDT SAT MAY 4 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 306 PM CDT SAT MAY 4 2013
MAIN FORECAST CONCERN IS ON FOG AND DENSE FOG POTENTIAL TONIGHT
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER LOWS OVER NORTHERN CALIFORNIA AND IN ARKANSAS...WHILE
AN UPPER HIGH WAS PRESENT ACROSS MUCH OF THE GREAT LAKES. FLOWING
BETWEEN THE ARKANSAS UPPER LOW AND THE GREAT LAKES UPPER HIGH WAS A
SHORTWAVE OVER CENTRAL WISCONSIN. DPVA AHEAD OF THIS SHORTWAVE
COMBINED WITH DAYTIME HEATING AND SOME EVAPOTRANSPORATION HAS AIDED
IN SHOWERS NORTH OF I-94. FARTHER SOUTH...SCATTERED SHOWERS ARE ALSO
PRESENT ACROSS PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST
WISCONSIN...AIDED BY INSTABILITY PRODUCED BY DEWPOINTS CLIMBING INTO
THE LOW 50S AND SOME COOLER TEMPS ALOFT. REGARDING TEMPERATURES...
THEY VARY GREATLY ACROSS THE FORECAST AREA...FROM THE 40S IN
ROCHESTER TO 60S ACROSS MUCH OF SOUTHWEST INTO CENTRAL WISCONSIN.
THE WARMER TEMPERATURES ARE A RESULT OF MORE SUN AND AN EASTERLY
FLOW OF WARMER AIR COMING OUT OF THE UPPER HIGH. 12Z GRB SOUNDING
SHOWED 900MB TEMPS OF +14C...COMPARED TO +5C AT MPX. BOTH SOUNDINGS
HAD AN INVERSION...BUT MPX WAS MUCH DEEPER AND THUS COMBINED WITH
THE CLOUDS WAS HELPING TO KEEP TEMPERATURES COOLER IN SOUTHEAST MN.
THE DEEPER INVERSION ALSO HAS HELPED TRAPPED PLENTY OF LOW LEVEL
MOISTURE...INCLUDING THAT FROM THE MELTING SNOWPACK...WHICH RESULTED
IN LOW VISIBILITIES OVER NORTHEAST IOWA...SOUTHEAST MINNESOTA AND
EVEN NORTH CENTRAL WISCONSIN THIS MORNING.
VERY LITTLE CHANGE IS FORECAST IN THE UPPER LEVEL PATTERN THROUGH
SUNDAY...EXCEPT FOR SOME UPPER RIDGING TRYING TO BUILD WESTWARD
THROUGH THE FORECAST AREA FROM THE UPPER HIGH. THIS UPPER RIDGING
SHOULD HELP TO KEEP THE FORECAST AREA DRY THROUGH SUNDAY AFTER ANY
SHOWERS FROM THIS AFTERNOON DISSIPATE WITH LOSS OF HEATING. THE
BIG ISSUE TONIGHT IS FOG. CONTINUING SNOW MELT OVER WESTERN AND
FAR NORTHERN PORTIONS OF THE AREA WILL HELP TO KEEP THE LOW LEVELS
OF THE ATMOSPHERE MOIST. MEANWHILE...MODELS MAINTAIN AN INVERSION
OVER THE SNOW PACK AREAS...WHICH MAKES SENSE WITH THE EASTERLY
FLOW OF WARMER AIR ALOFT ABOVE A NORTH-NORTHEAST FLOW OF COOL AIR
AT THE SURFACE. GIVEN THAT 1/4SM FOG FORMED THIS MORNING AND WINDS
ARE GOING TO BE EVEN LIGHTER...SITUATION SEEMS VERY FAVORABLE FOR
FOG AND EVEN DENSE FOG. ADDITIONALLY...SOME CLEARING COULD TRY TO
WORK IN BASED ON VISIBLE SATELLITE TRENDS...MAKING FOG EVEN MORE
FAVORABLE. SREF PROBABILITIES FOR VISIBILITY LESS THAN 1 MILE ARE
MUCH MORE EXPANSIVE AND HIGHER TONIGHT COMPARED TO THIS
MORNING...AND THE 04.00Z/06Z/12Z HIRES ARW/NMM ALL SHOW MORE FOG
TOO THAN THIS MORNING. LATEST HRRR/RAP ALSO DEVELOP FOG OVER THE
SNOW PACK. GIVEN THESE SIGNALS...HAVE INCREASED FOG COVERAGE AND
ISSUED A DENSE FOG ADVISORY...CONFINED TO THE AREAS WITH MELTING
SNOW PACK. COMBINATION OF HIGHER DEWPOINTS TONIGHT AND COME CLOUDS
WILL RESULT IN A WARMER NIGHT TONIGHT. WARMER TEMPERATURES ARE
ALSO ON TAP TOMORROW WITH MORE SUN LIKELY AS DRIER AIR COMING OUT
OF THE UPPER HIGH ADVECTS WESTWARD.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM CDT SAT MAY 4 2013
SUNDAY NIGHT THROUGH TUESDAY...NOT MUCH TO TALK ABOUT WITH REGARDS
TO THE UPPER LEVEL PATTERN. THE UPPER HIGH THAT IS OVER THE GREAT
LAKES SLOWLY BREAKS DOWN IN RESPONSE TO A SHORTWAVE TROUGH TRACKING
ACROSS NORTHERN ONTARIO COME MONDAY. STILL...THE FORECAST AREA JUST
SITS IN A LACK OF ANY UPPER LEVEL FLOW...SPLIT BETWEEN A SOUTHERN
STREAM TRACKING ACROSS THE SOUTHERN U.S. AND THE NORTHERN STREAM
WELL UP IN CANADA. MEANWHILE AT THE SURFACE...HIGH PRESSURE
CURRENTLY PRESENT OVER NORTHERN ONTARIO IS PROGGED TO BUILD SOUTH
INTO THE AREA DURING THIS PERIOD. DRYING AIR WITH THIS HIGH PRESSURE
AREA COMBINED WITH LACK OF ANY FLOW ALOFT WILL HELP TO KEEP THE
FORECAST AREA DRY. MAIN CONCERN AGAIN IS FOG. SREF PROBABILITIES FOR
VISIBILITY LESS THAN 1 MILE SHOOT BACK UP AGAIN SUNDAY NIGHT...
CONFINED TO THE SNOW PACK AREA. ONE QUESTION WOULD BE IS HOW MUCH
SNOW IS LEFT AFTER MELTING FROM THIS WEEKEND. HOWEVER...SOILS ARE
LIKELY GOING TO BE MOIST...AND WITH LIGHT WINDS AND CLEARING FROM
THE HIGH PRESSURE AREA BUILDING IN...RECIPE LOOKS GOOD AGAIN FOR FOG
AND EVEN DENSE FOG. MAY EVEN SEE FOG AGAIN MONDAY NIGHT...DEPENDING
IF THE SOIL IS STILL MOIST.
REGARDING TEMPERATURES THROUGH TUESDAY...850MB TEMPS ARE PROGGED TO
HOLD AROUND 8C FOR MONDAY AND THEN CLIMB TO NEAR 10C BY THE END OF
THE DAY TUESDAY. THESE READINGS ARE 0.5 TO 1 STANDARD DEVIATION
ABOVE NORMAL. BOTH DAYS SHOULD SEE QUITE A BIT OF SUN BEING IN
PROXIMITY TO THE SURFACE HIGH...THUS THINKING MIXING TO 850MB WILL
NOT BE A PROBLEM. THIS RESULTS IN HIGHS MAINLY IN THE LOW 70S ON
MONDAY AND LOW TO MID 70S ON TUESDAY. DID KEEP THE ROCHESTER AREA A
LITTLE COOLER ON MONDAY DUE TO WETTER SOIL. LIGHT WINDS AND DRY AIR
LIKELY TO RESULT IN DECENT COOLING AT NIGHT. FOLLOWED A BLEND OF MOS
GUIDANCE FOR LOWS.
TUESDAY NIGHT THROUGH SATURDAY...04.12Z ECMWF/GFS/CANADIAN AND ECMWF
ENSEMBLES SHOW THAT THE MORE ZONAL LOOKING NORTHERN STREAM WILL
BUCKLE DURING THE EXTENDED PORTION OF THE FORECAST. FOR FRIDAY AND
SATURDAY...GOOD AGREEMENT EXISTS IN FAIRLY DEEP TROUGHING OVER
CENTRAL CANADA...BEGINNING TO DROP DOWN TOWARDS THE FORECAST AREA.
IF THE 04.00Z/04.12Z ECMWF ARE CORRECT...WE COULD BE LOOKING AT A
SIGNIFICANT COOL DOWN HEADING INTO EARLY NEXT WEEK AS 850MB TEMPS
PLUMMET TO -8 TO -10C. BEFORE THAT TROUGH ARRIVES...THOUGH...A
SERIES OF WEAK COLD FRONTS / SYSTEMS ARE PROGGED TO COME THROUGH THE
AREA. THE FIRST MOVES THROUGH LATE WEDNESDAY. INSTABILITY BUILDING
AHEAD OF THIS FRONT...AIDED BY TEMPERATURES CLIMBING AT LEAST INTO
THE LOW IF NOT MID 70S...REQUIRES A CHANCE OF SHOWERS AND
THUNDERSTORMS. FOR THURSDAY INTO FRIDAY...THE 04.00Z/12Z ECMWF
INDICATES A SHORTWAVE TROUGH MOVING WEST TO EAST THROUGH THE
AREA...WHEREAS THE GFS AND CANADIAN KEEP THIS SHORTWAVE MUCH FARTHER
TO THE SOUTH. FOR NOW HAVE INCLUDED A CHANCE OF SHOWERS AND
THUNDERSTORMS UNTIL MODEL CONSISTENCY BECOMES BETTER. THEN FOR
SATURDAY WOULD BE THE STRONGER COLD FRONT ACCOMPANYING THE UPPER
TROUGH...THUS ANOTHER CHANCE OF PRECIPITATION. TEMPERATURES LOOK TO
STAY NEAR OR ABOVE NORMAL...UNTIL SATURDAY. SATURDAY COULD BE TRICKY
WITH HIGHS AS IT DEPENDS ON WHEN THE FRONT COMES THROUGH. 04.12Z
ECMWF IS SLOWER...WHICH WOULD SUGGEST THE BLEND OF ALL AVAILABLE
GUIDANCE MIGHT BE TOO COOL. WE WILL HAVE TO WAIT AND SEE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1240 PM CDT SAT MAY 4 2013
A COUPLE ITEMS TO LOOK AT THROUGH THE PERIOD. FIRST ITEM IS
SHRA/ISOLD T CHANCES GOING INTO THIS AFTERNOON/EARLY EVENING...AND
THE OTHER IS STRATUS/FOG DEVELOPMENT TONIGHT. CURRENT SURFACE
MAP/RADAR/VIS SATELLITE SHOWING LOW PRESSURE CENTERED OVER SW MO
WITH MOISTURE ROTATING AROUND IT INTO OUR AREA. MODELS DO DEVELOP
A SMALL AMOUNT OF INSTABILITY TO SUPPORT SOME SHOWERS/ISOLD T FOR
AREAS MAINLY ALONG/SOUTH OF I-94. CARRIED VCSH AT BOTH KRST/KLSE
FROM 20Z THROUGH 03Z. CIG/VIS EXPECTED TO BE VFR INTO EARLY THIS
EVENING...THEN RAPIDLY DETERIORATING INTO IFR/LIFR OVERNIGHT/EARLY
SUNDAY MORNING IN STRATUS/FOG AS THE VERY MOIST LOWER BOUNDARY
COOLS. LOOK FOR CONDITIONS TO SLOWLY IMPROVE AFTER 15Z SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 306 PM CDT SAT MAY 4 2013
AFTER SOME ISOLATED/SCATTERED RAIN SHOWERS THROUGH THIS
EVENING...A FEW DAYS OF DRY WEATHER ARE EXPECTED. THESE DRY DAYS
WILL BE BENEFICIAL...ALLOWING RUNOFF FROM THE RECENT RAIN AND
SNOWMELT TO WORK ITS WAY THROUGH THE TRIBUTARIES INTO THE MAIN
STEM OF THE MISSISSIPPI RIVER. MOST OF THE TRIBUTARIES ARE
REMAINING BELOW FLOOD STAGE. MEANWHILE...ALL THE WATER EVENTUALLY
LOOKS TO PUSH SOME SITES ALONG THE MISSISSIPPI RIVER RIGHT TO
FLOOD STAGE. SEE THE LATEST FLOOD AND RIVER STATEMENTS FOR MORE
INFORMATION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR WIZ032-033.
MN...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR MNZ079-
086>088-094-095.
IA...DENSE FOG ADVISORY FROM 1 AM TO 10 AM CDT SUNDAY FOR IAZ008-009-
018-019.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1240 PM CDT SAT MAY 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 256 AM CDT SAT MAY 4 2013
THE MAIN FOCUS FOR TODAY INTO TONIGHT IS WITH PRECIPITATION
CHANCES...THE POTENTIAL FOR DENSE FOG...AND HOW HIGH TEMPERATURES
WILL CLIMB TODAY.
A DEEPENING CUT OFF MID LEVEL LOW CONTINUES TO SLOWLY CHURN
EASTWARD ALONG THE MISSOURI/ARKANSAS BORDER AS A SURFACE LOW HAS
RETROGRADED TO THE WEST ACROSS CENTRAL ILLINOIS TOWARD THE
MISSOURI/IOWA BORDER. THIS HAS PULLED THE 925/850MB MOISTURE
TRANSPORT NORTHWEST INTO THE UPPER MISSISSIPPI VALLEY REGION WITH
SCATTERED CONVECTION DEVELOPING ALONG AND NORTH OF IT. AS THE
MID/LOW LEVEL LOW CONTINUES TO WRAP UP TODAY...THIS MOISTURE SURGE
SHOULD PUSH THE WEST WITH THE CONVECTION TRACKING THAT WAY AS
WELL EARLY THIS MORNING.
BEYOND THAT...AM NOT VERY CONFIDENT THAT THERE WILL BE MUCH IN THE
WAY OF CONVECTION ACROSS THE REGION WITH THE MAIN UPPER LEVEL
FORCING FROM THE LOW REMAINING TO THE SOUTH AND ANOTHER SHORT WAVE
STAYING WELL TO THE NORTH. THE MAIN FEATURE TO HELP TRIGGER ANY
SHOWERS/STORMS APPEARS TO BE WITH AN INVERTED SURFACE TROUGH THAT
IS CURRENTLY ALIGNED ALONG THE EASTERN SHORE OF LAKE MICHIGAN. THE
04.00Z NAM/GFS SHOW THIS FEATURE TRACKING WEST TODAY INTO
WISCONSIN AND SHOW SOME PRECIPITATION FORMING ALONG IT.
HOWEVER...THESE SAME MODELS BRING SURFACE DEW POINTS INTO THE LOW
60S AND DEVELOP A FEW HUNDRED J/KG OF SURFACE BASED CAPE IN AN
UNCAPPED ENVIRONMENT. MODIFYING THOSE SOUNDINGS TO HAVING DEW
POINTS IN THE LOW TO MID 50S YIELDS A CAPPED ENVIRONMENT WITH NO
SURFACE BASED CAPE. CURRENT DEW POINT ANALYSIS SHOWS THAT THE MAIN
SLUG OF HIGHER SURFACE DEW POINTS ARE CONFINED TO BEING JUST
EAST/NORTHEAST OF THE SURFACE LOW IN CENTRAL ILLINOIS WITH MID TO
UPPER 40S ELSEWHERE. WITH THIS SURFACE LOW DROPPING SOUTH
TODAY...EXPECT THAT THE BETTER CHANCES FOR CONVECTION WILL FOLLOW
IT AS WELL. SOME OF THE 04.00Z MESO-MODELS...SUCH AS THE NSSL
WRF...DO NOT CONVECT TODAY WHILE THE NMM AND THE 04.06Z HRRR DO
FORM SOME CONVECTION ALONG THE INSTABILITY AXIS WHERE THESE MODELS
FEATURE SURFACE DEW POINTS IN THE LOW 60S. BASED ON ALL
THIS...TRIED TO TREND PRECIPITATION CHANCES DOWN A BIT FOR TODAY.
TEMPERATURE-WISE FOR TODAY...FAIRLY HIGH BUST POTENTIAL BOTH WITH
POSSIBLY BEING TOO HIGH ON TEMPERATURES AND TOO LOW DEPENDING ON
THE LOCATION. LOW LEVEL EASTERLY WINDS WILL PULL A WARMER AIR
MASS INTO THE REGION TODAY...BUT HOW FAR WEST THIS AIR MAKES IT IS
THE MAIN QUESTION. HIGHS YESTERDAY IN LOWER MICHIGAN WERE IN THE
70S WHERE THIS AIR MASS WILL ORIGINATE FROM. HOW MUCH THE SNOW
PACK MELTS TODAY ACROSS SOUTHEAST MINNESOTA/NORTHEAST IOWA/NORTH
CENTRAL WISCONSIN WILL ALSO LIMIT TEMPERATURES A BIT THERE AS
WELL. DID NOT STRAY TOO FAR FROM GUIDANCE ON TEMPERATURES FOR
TODAY WITH HIGHER TEMPERATURES RANGING FROM THE UPPER 60S IN
EASTERN WISCONSIN TO THE UPPER 40S IN CENTRAL MINNESOTA.
WITH ALL OF THIS WARM AIR MOVING OVER A SNOW PACK AND OTHERWISE
MOIST SURFACES...EXPECT THAT THERE WILL BE FOG TONIGHT ACROSS MUCH
OF THE REGION. THE HIGHEST POTENTIAL FOR DENSE FOG WILL BE IN
THE AFOREMENTIONED SNOW PACK REGION WHERE A LOW LEVEL INVERSION
SHOULD TRAP MUCH OF THIS MOISTURE NEAR THE SURFACE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 256 AM CDT SAT MAY 4 2013
FOR SUNDAY INTO MONDAY...THE MAIN QUESTION WILL BE WHETHER ANY
CONVECTION WILL CONTINUE TO DEVELOP ALONG THE STALLED OUT INVERTED
SURFACE TROUGH WHICH APPEARS TO SET UP ALONG THE MISSISSIPPI
RIVER. THE 04.00Z NAM/GFS WANT TO DEVELOP MORE PRECIPITATION ALONG
THIS FEATURE BUT STILL HAVE WAY TOO HIGH OF SURFACE DEW POINTS
ALONG IT AND SHOW TOO HIGH OF INSTABILITY WITH NO CAPPING AS A
RESULT. KEPT THE FORECAST DRY OVER THIS PERIOD...BUT WILL HAVE TO
WATCH FOR ANY TRENDS THERE IN THE SURFACE DEW POINTS.
OTHERWISE...THE CORE OF THE UPPER LEVEL LOW PROPAGATES TO THE
SOUTHEAST INTO THE MIDDLE OF NEXT WEEK WITH ANOTHER CUT OFF LOW
MEANDERING THROUGH THE ROCKIES. CONDITIONS SHOULD MAINLY BE DRY
INTO MID WEEK BEFORE THE TROUGH PUSHES BACK TO THE EAST.
PRECIPITATION CHANCES MAY BE A BIT OVERDONE FROM WEDNESDAY THROUGH
FRIDAY...BUT BOTH THE 04.00Z GFS AND ECMWF DEVELOP SHOWERS
THROUGHOUT THE PERIOD WITH THE LOW MOVING IN ALONG WITH A COLD
FRONT DROPPING DOWN FROM CANADA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1240 PM CDT SAT MAY 4 2013
A COUPLE ITEMS TO LOOK AT THROUGH THE PERIOD. FIRST ITEM IS
SHRA/ISOLD T CHANCES GOING INTO THIS AFTERNOON/EARLY EVENING...AND THE
OTHER IS STRATUS/FOG DEVELOPMENT TONIGHT. CURRENT SURFACE
MAP/RADAR/VIS SATELLITE SHOWING LOW PRESSURE CENTERED OVER SW MO
WITH MOISTURE ROTATING AROUND IT INTO OUR AREA. MODELS DO DEVELOP
A SMALL AMOUNT OF INSTABILITY TO SUPPORT SOME SHOWERS/ISOLD T FOR
AREAS MAINLY ALONG/SOUTH OF I-94. CARRIED VCSH AT BOTH KRST/KLSE
FROM 20Z THROUGH 03Z. CIG/VIS EXPECTED TO BE VFR INTO EARLY THIS
EVENING...THEN RAPIDLY DETERIORATING INTO IFR/LIFR OVERNIGHT/EARLY
SUNDAY MORNING IN STRATUS/FOG AS THE VERY MOIST LOWER BOUNDARY
COOLS. LOOK FOR CONDITIONS TO SLOWLY IMPROVE AFTER 15Z SUNDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...DAS