River Flood Warning 42, NWS La Crosse, WI

Area Forecast Discussion
National Weather Service La Crosse WI
625 PM CDT Tue Apr 16 2019

.SHORT TERM...(This evening through Wednesday)
Issued at 344 PM CDT Tue Apr 16 2019

At 3 PM, a warm front was located near the Iowa and Missouri
border. Temperatures north of this front are in the 60s.
Meanwhile south of this front, temperatures were in the 70s and
lower 80s.

This front will gradually move north tonight and Wednesday as a
deepening low pressure system moves out of the Southern Plains
and Upper Mississippi Valley. Like the past couple of days, there
are still questions on far north this front will get. Many of the
deterministic models and a few convective producing models suggest
that it will move as far north Interstate 90 in western Wisconsin.
Meanwhile, the HREF has this front staying south of our area.
Both the GFS and NAM have most unstable CAPES climbing up to 1000
J/kg south of I-90, so there will be enough instability for some
scattered storms.

The 0-3 km shear still ranges from 30 to 40 knots. However, if
those storms do not become surface based, the 1-3 km shear is a
third to a half of those values and it would be unlikely for any
of these storms to become severe. Due to this uncertainty, like
the SPC marginal risk for our area. If severe did occur, it would
likely be a short window between 2 PM and 7 PM. Wind and hail
would be the primary concerns, but may have to watch the warm
front for the potential of an isolated tornado.

Precipitable water values will be in the 0.75 to 1 inch range.
This will result in some heavy rain at times. Both the NAM and
EWCMWF have rainfall totals ranging from a half to 1.5 inches
north of I-90 and up to a half inch across the remainder of the
area. Meanwhile, the GFS is further south with its heaviest
rainfall. It has 1 to 1.75 inches south of I-90 and anywhere from a
half to 1 inch across the remainder of the area.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 344 PM CDT Tue Apr 16 2019

On Thursday, a shortwave trough will be moving across the area.
This will result in scattered showers during the late morning and
afternoon. Rain totals look to be light with totals less than a
tenth of an inch.

Much of the Easter weekend is looking warm and dry. High
temperatures will range from the upper 50s to upper 60s. Both the
ECMWF and GEM keep the area dry. Meanwhile, the GFS has some light
rain along and south of I-90 on Sunday afternoon and evening.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 625 PM CDT Tue Apr 16 2019

Cigs: clouds will be thickening and lowering overnight/Wed morning
as a warm front approaches from the south. Saturation continues to
increase and deepen as Wed wears on (per RH fields and bufkit
soundings) and expectation is to drop into IFR/MVFR by 18z or so,
likely dropping a bit more before 00z. Low cigs look to hold at the
TAF sites into Thu.

WX: expecting shra to blossom along/north of a approaching warm
front after 12z Wed. Isold thunder also possible, but won't add to
forecast at this time. Should be a short window for morning showers.
Expect a break for the early part of the afternoon with more SHRA/TS
sparking ahead of a cold front for mid/late afternoon. Again, will
keep thunder out of the forecast, but see the potential for at least
VCTS. instability fairly meager thanks to low clouds, but enough
elevated for isold/sct thunder potential.

Winds: holding easterly for the most part, with a few gusts mainly
Wed morning. Could become more south if warm front moves north -
some uncertainty with how north it will get. Look for a swing to the
northwest with passage of cold front near/after 00z Thu.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&

SHORT TERM...Boyne
LONG TERM...Boyne
AVIATION...Rieck

Hazardous Weather Outlook
National Weather Service La Crosse WI
453 AM CDT Tue Apr 16 2019

IAZ011-030-MNZ079-088-096-WIZ032-033-041-053-054-061-171200-
Allamakee-Clayton-Wabasha-Winona-Houston-Buffalo-Trempealeau-
La Crosse-Vernon-Crawford-Grant-
453 AM CDT Tue Apr 16 2019

This Hazardous Weather Outlook is for portions of northeast
Iowa, southeast Minnesota, and southwest into western Wisconsin.

.DAY ONE...Today and Tonight

Flooding continues along portions of the Mississippi River.

There is a chance for thunderstorms tonight, mainly across
northeast Iowa and southwest Wisconsin. The main threat is
lightning.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Flooding will continue along portions of the Mississippi River,
with water levels gradually falling through the weekend.

There is a chance for thunderstorms Wednesday into Wednesday
night. A few storms Wednesday afternoon and evening could be
strong with a risk for hail, especially across northeast Iowa and
southwest Wisconsin. However, at this time, widespread severe
thunderstorms are not expected.

In addition, locally heavy rainfall is possible later tonight
through Wednesday evening. Should heavy rain become widespread,
additional flooding could result.

.SPOTTER INFORMATION STATEMENT...

No action needed.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

IAZ008>010-018-019-029-MNZ086-087-094-095-WIZ017-029-034-042>044-
055-171200-
Mitchell-Howard-Winneshiek-Floyd-Chickasaw-Fayette-Dodge-Olmsted-
Mower-Fillmore-Taylor-Clark-Jackson-Monroe-Juneau-Adams-Richland-
453 AM CDT Tue Apr 16 2019

This Hazardous Weather Outlook is for portions of southeast
Minnesota, northeast Iowa, and southwest into central Wisconsin.

.DAY ONE...Today and Tonight

There is a chance for thunderstorms tonight, mainly across
northeast Iowa and southwest Wisconsin. The main threat is
lightning.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

There is a chance for thunderstorms Wednesday into Wednesday
night. A few storms Wednesday afternoon and evening could be
strong with a risk for hail, especially across northeast Iowa and
southwest Wisconsin. However, at this time, widespread severe
thunderstorms are not expected.

In addition, locally heavy rainfall is possible Wednesday
through Wednesday evening. Should heavy rain become widespread,
additional flooding could result.

.SPOTTER INFORMATION STATEMENT...

No action needed.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

RRS/Lawrence