Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
207 AM EDT FRI AUG 28 2015

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 411 PM EDT THU AUG 27 2015

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW WNW FLOW INTO THE UPPER 
GREAT LAKES. RIDGE THAT EXTENDED FROM THE SRN ROCKIES TO SCNTRL 
CANADA YESTERDAY IS WEAKENING DUE TO SHORTWAVE ENERGY TRACKING FROM 
NRN ALBERTA TO NRN MANITOBA AND ANOTHER SHORTWAVE MOVING FROM WY 
INTO THE WRN PLAINS. THAT SHORTWAVE WILL BEGIN TO BECOME A FCST 
ISSUE HERE ON FRI. AFTER MORNING FOG...THE DAY HAS TURNED MOSTLY 
SUNNY...THOUGH AN ELEVATED SMOKE LAYER HAS LEFT THE SKY WITH A HAZY 
APPEARANCE. TEMPS HAVE REBOUNDED INTO THE MID 60S TO LWR 70S. 

QUIET WEATHER WILL CONTINUE TONIGHT AS DRY AIR IN A RELATIVE SENSE  
DOMINATES MOST OF THE COLUMN. LIGHT SOUTHERLY WINDS AND AN INCREASE 
IN PRECIPITABLE WATER WILL RESULT IN A WARMER NIGHT THAN LAST NIGHT. 
EXPECT MINS MOSTLY IN THE 50S...THOUGH DOWNSLOPE AREAS NEAR LAKE 
SUPERIOR MAY NOT FALL BLO 60F. 

ON FRI...THE WRN PLAINS SHORTWAVE WILL MOVE TO WI. BEST 
WAA/ISENTROPIC ASCENT ASSOCIATED WITH FEATURE SHIFTS FROM NRN IA/SRN 
MN INTO WI...SO BULK OF PCPN WILL PASS BY TO THE S OF HERE. THAT 
AREA IS ALSO WHERE MODELS SHOW HEAVIEST PCPN. PCPN CHANCES WILL BE 
MUCH MORE LIMITED TO THE N. WHILE HIGH RES WRF-ARW/NMM ARE LIKELY 
TOO AGGRESSIVE IN SPREADING PCPN INTO SCNTRL UPPER MI FRI...MOST 
MODELS DO BRING SOME PCPN INTO THE SCNTRL IN THE AFTN. WILL PAINT 
CHC POPS OVER THE FAR SCNTRL. DEPENDING ON CLOUD COVER/DAYTIME 
HEATING...THE GFS AND ESPECIALLY NAM BUILD A LITTLE BIT OF 
INSTABILITY PER MLCAPES FARTHER N. HAVE INCLUDED SCHC POPS FOR -SHRA 
IN THE EVENT A FEW -SHRA MANAGE TO POP IN THE AFTN.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 301 PM EDT THU AUG 27 2015

PLENTY OF UNCERTAINTY IN THE FIRST 24 HOURS OF THE LONG TERM...FRI
NIGHT AND SAT. A SHORTWAVE IS SET TO MOVE OUT OF THE CENTRAL PLAINS
AND MOVE THROUGH OR NEAR THE REGION DURING THIS TIME. THE 00Z/27
ECMWF IS DEEPEST AND FARTHEST NORTH WITH THE SHORTWAVE...WITH RAIN
OVER MOST OF THE CWA. THE 12Z/27 GFS IS QUITE A BIT WEAKER AND
FARTHER S...KEEPING MOST OF THE CWA DRY. THE 12Z/27 GEM AND 12Z/27
NAM MATCH CLOSER TO THE GFS...BUT DO BRING SOME PRECIP INTO THE SRN
CWA. WILL TEND TO FAVOR A GFS/NAM/GEM CONSENSUS GIVEN HOW MUCH OF AN
OUTLIER THE ECMWF IS. THIS RESULTS IN CHANCE POPS OVER SCENTRAL UPPER
MI FRI NIGHT AND SAT MORNING AND SLIGHT CHANCE POPS ELSEWHERE. DRY
CONDITIONS EXPECTED BY 00Z SUN.

MODELS CONTINUE TO BUILD AN UPPER RIDGE OVER THE REGION FROM SUN 
THROUGH THE REST OF NEXT WEEK. RAIN CHANCES WILL BE MINIMAL...BUT 
COULD SEE SOME CONVECTION WED OR THU IF SHORTWAVE ENERGY CAN ROUND 
THE TOP OF THE RIDGE...BUT CHANCES ARE LOW. THE AIRMASS WILL BE ON 
THE RISE...HOVERING AROUND 20C FROM LATE MON THROUGH THE REST OF THE 
WEEK. THIS RESULTS IN TEMPS BEING 10 OR MORE DEGREES ABOVE NORMAL 
FROM MON ON.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 207 AM EDT FRI AUG 28 2015

RELATIVELY DRY AIR MASS OVER THE AREA SHOULD ENSURE VFR CONDITIONS 
CONTINUE THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT THU AUG 27 2015

A GENERALLY WEAK PRES GRADIENT WILL DOMINATE THE UPPER LAKES INTO 
EARLY NEXT WEEK. ON MOST DAYS...WINDS WILL BE UNDER 15KT...BUT THERE 
WILL BE SOME PERIODS WHERE GUSTS WILL GET INTO THE 15-20KT RANGE. 
LOOKS LIKE THE LIGHTEST WINDS WILL OCCUR OVER THE WEEKEND WITH HIGH 
PRES RIDGE MORE FIRMLY IN CONTROL.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON

National Weather Service Glossary of Abbreviations