Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 030627
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
227 AM EDT THU SEP 3 2015

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 225 AM EDT THU SEP 3 2015

HIGH IMPACT WEATHER: SHOWERS AND STORMS. HEAVY RAINFALL AGAIN.

SYNOPTIC PATTERN AND OBSERVATIONS:

EARLY MORNING ANALYSIS...RIDGING ALOFT AND WARM TEMPERATURES COVERED
MOST OF THE COUNTRY...WITH TROUGHING PUNCHING IN ACROSS THE PACIFIC
NW. WITHIN THE RIDGING...AND OVER THE WESTERN GREAT LAKES...WAS A
SHORTWAVE TROUGH...WHILE AN EARLIER MCV FROM AFTERNOON STORMS IN
EASTERN WISCONSIN...RAN THROUGH THE STRAITS. THIS MCV SPREAD SOME
SPRINKLES IN SRN SECTIONS OF EASTERN UPPER...BUT THE MAIN ACTION WAS
WITHOUT A DOUBT THE LOCALLY HEAVY RAINFALL ACROSS SECTIONS OF NC/NE
LOWER MICHIGAN FROM YESTERDAY. THE MCV IS LOSING IT`S STRENGTH AND
ALSO RUNNING INTO SLIGHTLY LESS FAVORABLE ATMOSPHERIC INGREDIENT FOR
CONTINUED RAINS. ATTENTION TURNS TO THE SHORTWAVE TROUGH UPSTREAM IN
WISCONSIN...WHERE LOW TO MID LEVEL WAA ON NOSE OF WEAKISH LLJ...HAS
EXPANDED RAINFALL WITH EMBEDDED HEAVY SHOWERS AND STORMS. RAINFALL
RATES IN THE STRONGER SHOWERS RANGED FROM 0.5" TO 1.0". QUESTION IS
HOW WELL WILL THESE RAINS HOLD TOGETHER AS THEY CONTINUE TO TRACK
EASTWARD INTO NW LOWER THROUGH DAYBREAK? THE FOLLOWING QUESTION WILL
BE HOW MUCH COVERAGE AND INSTABILITY CAN WE GENERATE FOR ADDITIONAL
HEAVY RAINS TODAY?...AND HOW WILL THAT PRECIPITATION EVOLUTION
TRANSLATE INTO TONIGHT? WILL HAVE TO KEEP A CLOSE EYE ON FLOODING
FOR PORTIONS OF OTSEGO AND MONTMORENCY COUNTIES...AS WELL AS THE I-
75 CORRIDOR IN OGEMAW...GLADWIN AND ARENAC COUNTIES...WHERE SOME OF
THE HEAVIEST RAINS FELL.

SYNOPTIC PATTERN EVOLUTION AND ASSOCIATED WEATHER:

THE MCV HAS TRACKED THROUGH EASTERN UPPER AND PROVIDED SOME LIGHT
RAIN/SPRINKLES...WHILE THE SHORTWAVE FROM WISCONSIN HAS A WELL
IDENTIFIED VORT MAX SPINNING ITS WAY TOWARD NW LOWER MICHIGAN. THIS
FEATURE WILL BRING SHOWERS AND STORMS INTO WESTERN AREAS OF THE CWA
THROUGH DAYBREAK...WITH EXACT EVOLUTION OF PRECIPITATION THROUGH
LATE MORNING UNKNOWN. MOST ALL OF NRN LOWER HOWEVER WILL BE SEEING
ADDITIONAL SHOWERS AND STORMS TODAY...AIDED BY WHATEVER DAYTIME
HEATING WE CAN GET...PLUS THE FORCING FROM THE WAVE. STILL LOOKING
LIKE THE AFTERNOON HOURS...LESS ACTIVITY FOR EASTERN UPPER. NOT AS
MUCH INSTABILITY AS YESTERDAY (500-800J/KG OF MLCAPE)...SO STORMS
SHOULD BE MORE GARDEN VARIETY...BUT STILL POSING THE THREAT FOR
HEAVY RAIN/FLOODING ISSUES. THIS THREAT CONTINUES INTO TONIGHT...BUT
WITH MORE UNCERTAINTY. THE SHORTWAVE REMAINS OVER NRN MICHIGAN WITH
TOO DIFFICULT OF A TASK TO DETERMINE WHERE THE BEST FORCING WILL
RESIDE. THE THING OF IMPORTANCE IN THE POSSIBILITY OF SOME AREAS
GETTING CONTINUAL HIGH PRECIPITATION EFFICIENCY...AND RESULTING
FLASH FLOODING POTENTIAL. THIS THREAT IS RATHER LOCALIZED AND WITH
LOSS OF THE BETTER INSTABILITY...NO WATCH PRODUCTS FOR FLOODING WILL
BE ISSUED. MORE THAN LIKELY TONIGHT...DO EXPECT A DROP IN SHOWER
COVERAGE AND INTENSITY...AS MORE DATA THAN NOT SUGGESTS A WEAKENING
UPPER TROUGH. BEST ACTION IS EXPECTED TO SAG SOUTH OF M-32 THROUGH
THE NIGHT.

HIGHS RANGING IN THE LOWER HALF OF THE 80S...WITH LOWS TONIGHT IN
THE MIDDLE AND UPPER 60S.

&&

.SHORT TERM...(THURSDAY THROUGH SATURDAY)
ISSUED AT 345 PM EDT WED SEP 2 2015

THURSDAY THROUGH SATURDAY...THE LARGE AREA OF HIGH PRESSURE WHICH
HAS BEEN ANCHORED OVER THE ERN TWO THIRDS OF THE COUNTRY SINCE THE
BEGINNING OF THE WORK WEEK...WILL REMAIN NEARLY STATIONARY INTO THE
UPCOMING HOLIDAY WEEKEND WHILE A STORM SYSTEM TRIES TO ORGANIZE OVER
THE ROCKIES. AT UPPER LVLS...BROAD 500MB RIDGE WHICH BUILT OVER
MUCH OF THE COUNTRY TO BEGIN THE WORK WEEK...WILL SHARPEN EAST OF
THE ROCKIES BY FRIDAY WHILE A TROUGH DEEPENS OVER THE PACIFIC
NORTHWEST. THIS PATTERN WILL GENERATE MAINLY DRY CONDS ACROSS MUCH
OF THE GREAT LAKES THROUGH THE WEEKEND. HOWEVER...A WEAK RIPPLE
DEVELOPING IN THE 500MB FLOW OVER THE WRN LAKES WILL MOVE ACROSS THE
REGION THURSDAY. MODEL SOUNDINGS AND MSTR PROGS SHOWING PLENTY OF
LOW AND MID LVL MSTR (SFC DEW PTS NEAR 65F WITH 850MB DEW PTS NEAR
17C) IN PLACE IN ADVANCE OF THE BOUNDARY TO GENERATE CONVECTION OVER
NRN MI THURSDAY AFTERNOON AND EVENING (MU CAPE ~2500 J/KG, LI ~
-4C WITH 850/500MB LAPSE RATES OF 6-7C/KM). CORRESPONDING MID LVL
QVECTORS SHOWING THE BEST CONVERGENCE ASSOCIATED WITH APPROACHING
UPPER TROUGH...EXITING EAST OF THE REGION BY 00Z FRI.

THE EXTEND PERIOD OF WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE
ACROSS THE GREAT LAKES THROUGH THE FCST PD...WITH CONTINUED PRESENCE
OF SURFACE AND UPPER LVL RIDGE IN PLACE FROM THE GULF STATES THROUGH
THE OHIO VALLEY. 850MB TEMPS ASSOCIATED WITH THIS PATTERN WILL
SLOWLY WARM FROM AROUND 16C THURSDAY TO AROUND 20C OVER THE WEEKEND.
THIS PATTERN SHOULD GENERATE AFTERNOON TEMPS IN THE MID 80S ACROSS
NRN MI THURSDAY AND FRIDAY WITH HIGHS WARMING INTO THE UPPER 80S
SATURDAY.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 PM EDT WED SEP 2 2015

FLATTENING OF THE H5 RIDGE THAT WAS SETUP OVER THE GREAT LAKES WILL
HELP TO USHER OUT THE WELL ABOVE NORMAL TEMPERATURES FROM EARLIER IN
THE WEEK. SUNDAY AND MONDAY WILL STILL BE WELL ABOVE NORMAL...BUT
TEMPERATURES WILL DIP BY MIDWEEK. A WEAK COLD FRONT...ATTENDANT TO
LOW PRESSURE MOVING THROUGH ONTARIO...WILL HELP TO KNOCK
TEMPERATURES DOWN SOME EARLY IN THE WEEK AND BRING THE POSSIBILITY
OF SOME WIDESPREAD SHOWERS. NOT A LOT OF AGREEMENT WITH TIMING RIGHT
NOW...BUT THIS COULD AFFECT SOME LABOR DAY ACTIVITIES. A SECOND
SYSTEM...MOVING OUT OF THE PLAINS...WILL BRING ANOTHER CHANCE OF
MORE WIDESPREAD SHOWERS FOR MIDWEEK AND HELP TO GET TEMPERATURES
BACK DOWN TO NORMAL RANGES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1151 PM EDT WED SEP 2 2015

...SOUPY CONDITIONS PERSIST...

WARM/HUMID AIRMASS ACROSS THE REGION WILL LEAD TO MVFR AND
POSSIBLE IFR FOG AT THE TERMINAL SITES AGAIN OVERNIGHT.

SLOW MOVING SHORT WAVE TROUGH OVER WESTERN UPPER MICHIGAN/EASTERN
WISCONSIN WILL SLOWLY WORK EASTWARD INTO NRN LOWER MICHIGAN
OVERNIGHT AND HANG OVERHEAD THROUGH THE DAY THURSDAY. ASSOCIATED
BATCH OF SHOWERS/THUNDER WILL GRADUALLY PUSH INTO NRN LOWER
MICHIGAN LATE OVERNIGHT AND PERCOLATE ACROSS NRN LOWER MICHIGAN
THROUGH MUCH OF THE DAY THURSDAY...ALTHOUGH BULK OF PRECIP WILL
TEND TO CONTRACT INLAND. THUS...ANTICIPATE ANOTHER ROUND OF PRECIP
TO IMPACT THE TERMINAL SITES LATER OVERNIGHT OR THURSDAY MORNING
(APN).

SHOWERS WILL DIMINISH THURSDAY EVENING AND LIKELY SET THE STAGE
FOR MORE SOUPY CONDITIONS THURSDAY NIGHT.

WINDS...UNDER 10 KNOTS ALL THE WAY THROUGH THE TAF PERIOD.


&&

.MARINE...
ISSUED AT 225 AM EDT THU SEP 3 2015

LOW PRESSURE WILL DRIFT INTO NRN MICHIGAN TODAY...BRINGING MORE
SHOWERS AND EMBEDDED STORMS. STORMS WILL BE WEAKER THAN YESTERDAY
WITH NO EXPECTED ISSUES FOR WAVES/WINDS. HEAVY RAIN IS EXPECTED
HOWEVER. LOTS OF UNCERTAINTY ON HOW LONG THIS LOW PRESSURE
LINGERS...BECAUSE IT SURE DOESN`T WANT TO LEAVE. SHOWERS COULD BE
POSSIBLE THROUGH SATURDAY. WINDS OVER THIS TIME HOWEVER...ARE
EXPECTED TO BE RELATIVELY LIGHT.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...ADAM
NEAR TERM...SMD
SHORT TERM...SWR
LONG TERM...ALM
AVIATION...ADAM
MARINE...SMD


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