Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

FXUS63 KDVN 130430

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1130 PM CDT Mon Mar 12 2018


Issued at 315 PM CDT Mon Mar 12 2018

A strong Canadian high pressure continues to build into the upper
Midwest today, with mostly sunny to sunny skies found over Iowa and
western Illinois.  The departing moisture to the east is close
enough to allow for some cumulus over our eastern Illinois counties,
but this has had little impact on temperatures today. The deep
mixing and nearly full sun have brought widespread mid 40s to the
area, with our far northwest, which still has snow cover as of 2 PM,
staying in the mid 30s. No doubt that that snow cover is thinning,
but by all satellite appearance, it seems like it will live on
another day.


.SHORT TERM...(This Evening through Tuesday)
ISSUED AT 315 PM CDT Mon Mar 12 2018

Tonight, I have gone with the guidance blend, which seems to
capture the cool night, but keep enough mixing to prevent a true
plunge in low temperatures. I did adjust lows down about 5 degrees
over the snow pack in the northwestern counties, which result in
upper teens there, and 23 to 25 elsewhere in the CWA. Tuesday, no
real change is expected, as the CU rule again supports some cloud
cover east, and mainly clear central and west. That will bring
another cool and brisk day, in the mid 30s north to lower 40s
south. The peak winds of the afternoon appear to be 20 to 25 kts
in the deepest mixing hours. Those winds will again support a
somewhat elevated fire danger risk as afternoon humidity levels
drop below 45 percent, especially in northeast Missouri and
southeast Iowa. ERVIN

.LONG TERM...(Tuesday Night through next Monday)
ISSUED AT 315 PM CDT Mon Mar 12 2018

Tuesday night and Wednesday...Sfc ridge on track to slide acrs the
area from the west Tue night for sfc wind decrease and temp crash
well down in the 20s and even some upper teens in the north. Ongoing
steep northwest flow to shunt a boundary down toward the area behind
passing sfc ridge for Wednesday. This process will look to induce
rather breezy return flow southwesterly winds by Wed afternoon of 15
to 20+ MPH. These winds combined with lowering RH to probably
support an enhanced grass fire risk Wed afternoon into the evening.
Much of the CWA to see highs in the 50s on Wed. The front will look
to get shunted southeastward in a dry fashion through the area Wed
evening. Seasonable lows for Wed night into early Thu morning.

Thursday and Friday...Mid CONUS omega block will look to hang on
long enough for a dry Thursday(but cooler post-frontal temps than
Wed), before western flank wave energy becomes more established acrs
the southwestern plains by Friday morning. This wave to induce some
overrunning precip up over the boundary shunted to the south acrs KS
and MO, but the 12z run medium range models vary on how far north
the precip will make it, battling post-frontal east-northeast
boundary layer flow. The 12z GFS brings an elevated band of rain
acrs the southern third of the CWA Thu night, with some precip type
issues developing on it`s cooling northern flank. The 12z ECMWF is
largely dry until a few sprinkles try to get acrs the far southern
CWA until late Friday afternoon. Will have to carry POPs in the
south Thu night for continuity for now with previous runs and await
further trends.

Saturday through next Monday...A potentially rather active period as
the Omega block partially breaks down and mid ridge undercutting
waves roll out somewhere acrs the Midwest. Large model descrepancies
continue for low confidence through the period, and model blends
making for POPs for portions of the area almost every day. While
the GFS shunts the main first wave south of the area with a clipping
blow in the southern CWA Thu night into Friday morning, then a
mainly dry Fri night and St Patrick`s Day Saturday, with highs
possibly getting a few degrees above normal Saturday if a more
southelry LLVL wind component pans out as opposed to easterly. This
in large contrast to the new 12z Euro which rolls out the main wave
Fri night into Sat and further north, with rain and snow potential
Fri night, changing back over to rain and diminishing on Saturday.
again with the descrepancies and model blends, POPs will have to be
carried Fri night Sat. The next wave will then be on track for
potentially wet and cool conditions acrs the region Sunday night into
Monday. Strength, how far north or south the system will track, and
thermal profiles it will utilize for precip types still vary much up
in the air at this juncture of the game, but again with potentially
active pattern, POPS will ride into Monday with ensemble high POPs
taking place acrs the south late Sunday night into Monday. ..12..


.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
ISSUED AT 1128 PM CDT Mon Mar 12 2018

VFR conditions with clear to fair skies will exist for at least the
next 24 hours as high pressure moves in. Northwest winds overnight
around 10 mph will increase to 15 mph up to near 25 mph in gusts during
the day on Tuesday.





AVIATION...16 is the U.S. government's official web portal to all federal, state and local government web resources and services.