National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KDLH 210901
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
401 AM CDT TUE MAY 21 2013

.SHORT TERM...CWA REMAINS UNDER LARGE ANOMALOUS CIRCULATION THAT HAS
BEEN TRAPPED OVER CTRL CONUS LAST FEW DAYS. ANOTHER BAND OF RAIN
IS ROTATING AROUND THE SYSTEM AND PUSHING INTO THE SRN CWA. WILL
LET FFA CONTINUE THROUGH MORNING ALTHOUGH BIGGEST THREAT APPEARS
TO BE ACROSS SRN CWA WHERE MAIN FORCING SHOULD OCCUR.

TODAY...AREA OF RAIN/THUNDER CURRENTLY OVER SRN CWA IS ALIGNED WITH
SHARPENING 85H THETAE AXIS AS IT WRAPS INTO MID LVL LOW. THIS
FEATURE IS FCST TO STRETCH EAST TO WEST ACROSS SRN CWA TODAY.
LIMITED CONVECTIVE POTENTIAL AS CLOUD CANOPY AND DEEPLY SATURATED
COLUMN MAKE FOR SOME LOW CAPE VALUES SFC/ALOFT. MOST FAVORABLE
COMBO OF INSTABILITY/SUFFICIENT DEEP LAYER SHEAR IS OVER SERN WISC
ZONES IN THE AFTN. AREA OF FRONTOGENESIS THAT HAS BEEN FAIRLY
PERSISTENT OVER NRN MN ZONES IS FCST TO WEAKEN SO HAVE TAPERED POPS
THROUGH THE AFTN HRS. ANOTHER CHILLY DAY NEAR LAKE SUPERIOR AS
STRONG ONSHORE FLOW/CLOUDS/PRECIP LIMITS TEMP RISE.

TONIGHT...DEEP LAYER DRYING SHOULD BEGIN TO PUSH FARTHER SOUTH INTO
MN ZONES. BEST THERMODYNAMICS...85H THETAE AXIS...SHIFTS SOUTH OF
REGION BY 12Z. BRD LAKES REGION MAY REMAIN UNDERNEATH MID LVL
CYCLONIC CIRCULATION AND COLLAPSING LOW LVL THETAE RIDGE LONG
ENOUGH TO KEEP QPF A BIT HIGHER THAN REMAINDER OF CWA.

TOMORROW...MID LVL LOW SLIDES SOUTHEAST OF CWA AND RIDGING BUILDS
ALOFT. SFC HIGH INCREASES AND PWATS DROP CONSIDERABLY DURING THE
DAY. SHOULD BE ENOUGH SUNSHINE TO MAKE NWRN PART OF CWA THE WARMEST
WITH LOWEST READINGS OCCURRING IN SERN CWA.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY.

THE MASSIVE LOW PRESSURE SYSTEM THAT HAS AFFECTED THE REGION THE
PAST SEVERAL DAYS WILL FINALLY PULL OUT OF THE NORTHLAND COMPLETELY
WEDNESDAY NIGHT...AS DRY HIGH PRESSURE BUILDS IN FROM THE NORTH. ON
THURSDAY WE COULD SEE VERY LOW RELATIVE HUMIDITY VALUES...AFTER
SEEING HIGH RELATIVE HUMIDITY FOR QUITE SOME TIME. THE DRY AIR FROM
THE HUDSON BAY HIGH WILL LIKELY LAST INTO FRIDAY NIGHT BEFORE SOME
PRECIPITATION POSSIBLY MAKES IT INTO AT LEAST THE SW HALF OF THE
REGION. DO THINK IT IS POSSIBLE THAT THE DRY HIGH PRESSURE SYSTEM
COULD HOLD OFF THE PRECIPITATION THROUGHOUT THE WEEKEND AND MAYBE
EVEN INTO THE FIRST PART OF THE UPCOMING WORK WEEK. THE ECMWF IS
MOST DRY ACROSS THE AREA...WITH THE GFS AND GEM BRINGING SOME
PRECIPITATION INTO THE CWA. HIGH TEMPERATURES WILL LARGELY BE IN THE
60S FOR THE ENTIRE EXTENDED WITH COOLER TEMPS NEAR LAKE SUPERIOR.


.AVIATION...06Z TAF ISSUANCE...

IFR CIGS AND MVFR VSBYS IN SCATTERED RAIN SHOWERS AND PATCHY FOG
TONIGHT AND MOST OF TUE...ALONG WITH A FEW ISOLATED STORMS OVER HYR
EARLY TUE MORNING. WINDS WILL CONTINUE TO BE GUSTY FROM THE
NE...WITH THE STRONGEST WINDS AROUND DLH. COULD SEE ANOTHER ROUND OF
AFTERNOON SHOWERS AND STORMS MOVE IN FROM THE SOUTH DURING THE
AFTERNOON ON TUESDAY...WITH THE SRN TERMINALS HAVING THE BEST CHANCE
OF BEING IMPACTED...MAINLY HYR ONCE AGAIN.



.POINT TEMPS/POPS...
DLH  49  41  57  41 /  70  60  50  10
INL  52  40  66  39 /  60  30  10   0
BRD  57  45  61  44 /  70  60  50  10
HYR  64  44  56  42 /  70  60  60  20
ASX  49  40  52  40 /  80  50  60  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR MNZ010>012-
     018>021-025-026-033>038.

WI...FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR WIZ001>004-
     006>009.

LS...DENSE FOG ADVISORY UNTIL 11 AM CDT THIS MORNING FOR LSZ121-
     140>148.

     SMALL CRAFT ADVISORY UNTIL 11 AM CDT WEDNESDAY FOR LSZ121-
     140>148.

&&

$$

SHORT TERM...CANNON
LONG TERM....DAP