AWUS01 KWNH 110853
FFGMPD
OHZ000-INZ000-ILZ000-111400-

Mesoscale Precipitation Discussion 0060
NWS Weather Prediction Center College Park MD
452 AM EDT Wed Mar 11 2026

Areas affected...eastern IL, central IN into northern OH

Concerning...Heavy rainfall...Flash flooding possible

Valid 110851Z - 111400Z

SUMMARY...Areas of training will increase the potential for
localized flash flooding from portions of eastern IL into central
IN and northern OH through 14Z. Rainfall rates of 1-2 in/hr and
storm total rainfall of 2 to 4+ inches can be expected.

DISCUSSION...0830Z regional radar imagery showed a broken and
elongated axis of thunderstorms from near St. Louis into central
IL and western IN, followed by another linear segment over
northeastern IN into northwestern OH. These convective axes were
located within the warm sector of a WSW-ENE oriented frontal
boundary, represented by 500 to 1500+ J/kg MLCAPE from
south-central IL into northwestern OH along with PWs of about 1.0
to 1.5 inches (08Z SPC mesoanalysis).

Some minor strengthening of 925-850 mb southwesterly flow (up to
~60 kt) is expected to advance from southern IL into IN and
eventually western OH over the next few hours, helping to focus
one more more axes of convergence near convectively induced
outflow boundaries which will at times be in general alignment
with the mean steering flow from the WSW to SW. This setup will
support training of heavy rain at times with 1 to 2 inches per
hour likely within any axes of training.

Forecasts of instability from the RAP are for a gradual reduction
through 14Z across IL/IN/OH which will act to decrease rainfall
intensity but strong divergence within the right-entrance region
of a powerful 150+ kt upper jet max to the north may help to
compensate for the forecasts of lessening instability. Therefore,
a chance for localized flash flooding seems plausible across the
Midwest over the next 3-6 hours with potential for storm totals of
2 to 4+ inches.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_Z8cFphTvW_N8XFRMYwpQkbaXxErJGIprrWPEANPT9DQhVwQmEJMv9LGPheKZYpsmAo5= hBXdZ-oVJ1wK-8GuROINSvE$ for graphic product...

ATTN...WFO...CLE...ILN...ILX...IND...IWX...LOT...

ATTN...RFC...MSR...TIR...NWC...

LAT...LON 42108112 41728081 41108194 40548310 39458592=20
39148846 40248901 41158743 41688553 41668451=20
41668360 41718284=20

=3D =3D =3D
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AWUS01 KWNH 110956
FFGMPD
MSZ000-LAZ000-ARZ000-TXZ000-111500-

Mesoscale Precipitation Discussion 0061
NWS Weather Prediction Center College Park MD
555 AM EDT Wed Mar 11 2026

Areas affected...northeastern TX into central/southern AR and
northwestern LA

Concerning...Heavy rainfall...Flash flooding possible

Valid 110954Z - 111500Z

SUMMARY...A continued increase in thunderstorm intensity and
potential training appears likely over the next few hours from
northeastern TX into central/southern AR and northwestern LA.
Training of thunderstorms will support hourly rainfall of 1 to 2+
inches and possible flash flooding through 15Z.

DISCUSSION...Trends in GOES East infrared satellite imagery over
northeastern TX through 0930Z have shown an increase in colder
cloud tops over the past hour, related to an increase in rainfall
intensity along a narrow convective axis, out ahead of a forward
propagating convective line extending from the southern OK/AR
border into east-central TX. This activity was located to the
north of a weakly defined outflow boundary which has made it all
the way to the Houston metro and the recent uptick appears to be
related, at least in part, to increased low level moisture seen
advecting north on OSPO ALPW imagery in the surface to 700 mb
layer over eastern TX/western LA. Confluent flow just above the
surface located beneath modestly diffluent upper level winds was
observed over the TX/AR border where 500-1500 J/kg MLCAPE was
estimated on the 09Z SPC mesoanalysis with little to no inhibition.

Low level moisture transport into the region and low level
confluence appear to remain in the short term forecast across the
ArkLaTex and eastward into southern AR and northwestern LA. Given
sufficient instability looks to remain present across the region
over the next 3-6 hours via recent RAP forecasts, an axis of heavy
rain looks likely to setup from northeastern TX into AR/LA. While
this expected SW to NE axis of heavy rain should generally move
from west to east, there is the potential for the southwestern
flank of the axis to stall, supporting the potential for increased
training and rain rates that could exceed 2 in/hr. However, more
likely rain rates within training should fall in the 1-2 in/hr
range. Through 15Z, 2 to 4+ inches of rain will be possible, much
of which could fall within 2-3 hours.

Otto

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9uI-asL2kWpYIuDXduHCMxNuxYzA8JgQ7Ajo5KuVy07eO8Qqht4G9OoHK1K5yMdEgfj6= 8Bl-L0RfqDeiXC9FeahlHVw$ for graphic product...

ATTN...WFO...HGX...JAN...LZK...MEG...SHV...

ATTN...RFC...FWR...ORN...TUA...NWC...

LAT...LON 35309103 34999037 33429120 31619338 31059480=20
31729528 33069475 34859258=20

=3D =3D =3D
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AWUS01 KWNH 111652
FFGMPD
NYZ000-PAZ000-WVZ000-OHZ000-KYZ000-INZ000-ILZ000-112250-

Mesoscale Precipitation Discussion 0062
NWS Weather Prediction Center College Park MD
1250 PM EDT Wed Mar 11 2026

Areas affected...Portions of the OH Valley and Lower Great Lakes

Concerning...Heavy rainfall...Flash flooding possible

Valid 111650Z - 112250Z

SUMMARY...Broken clusters of locally heavy showers and
thunderstorms will continue through the afternoon hours. Locally
high rainfall rates, moistening antecedent conditions and some
cell-training concerns will maintain a threat for additional
runoff problems including isolated to scattered areas of flash
flooding.

DISCUSSION...The latest GOES-E satellite imagery along with radar
shows broken clusters of heavy showers and thunderstorms advancing
across the OH Valley and Lower Great Lakes region. More broadly,
this activity is associated with strong warm air advection and
moisture transport continuing to lift northeastward ahead of a
wave of low pressure over southern Lower MI by also with the
advance of multiple shortwave impulses across the region.

Warm-sector diurnal heating with increasing solar insolation is
noted over central and southern OH and extending back to the
southwest over northern KY, southern IN and southeast IL. This has
allowed for these areas to increasingly destabilize, and MUCAPE
values of 1000 to 1500 J/kg are noted here with 3-hour MUCAPE
differentials of locally 250 to 500+ J/kg seen from far southern
IN and northern KY through central WV. This is allowing for a
well-defined differential heating/outflow boundary to establish
itself which is expected to become an increasing focus for
convection going through the afternoon hours. This will further be
facilitated by arrival of a new shortwave impulse from the Midwest
which should yield favorable 400 to 700 mb DPVA within the broader
warm air advection regime to drive deeper layer ascent.

Meanwhile, areas downstream over western PA and far western NY are
under the influence of a lead shortwave impulse with focused warm
air advection and DPVA yielding broken areas of convection. Some
hints at mesocyclone activity is noted in radar over Lake Erie,
and this may help to bring locally focused rains into far western
NY in a couple of hours. The 12Z HREF/06Z REFS guidance does
attempt to bring the upstream convection back over some areas of central/southern OH through northern WV and southwest PA later
today.

Expecting a gradual uptick in rainfall rates capable of reaching
1.5"/hour with the stronger storms. Given the cell-training
concerns near the aforementioned differential heating/outflow
boundary, some additional rainfall totals of 2 to 3 inches will be
possible. This will pose a threat for isolated to scattered areas
of flash flooding.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4epEr0m_uTWVSbIfLr7vCQwmeFuPccCynI3AOkF4kTvyEbQ64setvRY_4fU5ij9gNgh0= Y3tb4NkGOR-qT7LFqWi1mCs$ for graphic product...

ATTN...WFO...BUF...CLE...CTP...ILN...ILX...IND...IWX...JKL... LMK...LSX...PAH...PBZ...RLX...

ATTN...RFC...MSR...RHA...TAR...TIR...NWC...

LAT...LON 42827882 42437812 40997863 39528042 38428376=20
37878744 38018892 38448943 38948890 40148540=20
40948307 42168059=20

=3D =3D =3D
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AWUS01 KWNH 151842
FFGMPD
FLZ000-160000-

Mesoscale Precipitation Discussion 0063
NWS Weather Prediction Center College Park MD
240 PM EDT Sun Mar 15 2026

Areas affected...South FL

Concerning...Heavy rainfall...Flash flooding possible

Valid 151840Z - 160000Z

SUMMARY...Slow-moving clusters of showers and thunderstorms with
extreme rainfall rates may cause flash flooding going through
early this evening. This could include some urban impacts.

DISCUSSION...The latest GOES-E IR satellite imagery along with
radar shows slow-moving clusters of very heavy showers and
thunderstorms impacting portions of Miami-Dade and Collier
Counties.

This convection is focusing within a moist and unstable
environment characterized by MLCAPE values of 1500 to 2500 J/kg
and PWs of 1.5 to 1.7 inches. Some modest shear is in place with
as much as 20 to 30 kts of effective bulk shear. Much of the
activity recently though is tending to get its focus along the
presence of multiple mesoscale boundaries including outflow and
sea-breeze boundaries where there is small-scale convergence
working with the favorable thermodynamic environment.

Some modestly divergent flow aloft is noted also given proximity
of a weak shortwave west of the FL Straits and Cuba. This modest
deep layer ascent coupled with colliding surface boundaries should
tend to keep the convective threat maintained going into the
evening hours before sufficient levels of instability exhaustion
occurs to promote a weakening trend of the convection.

Already parts of the FL Everglades in Miami-Dade County have seen
over 5 inches of rain, with much of the activity staying away from
the urban areas. However, over the next few hours there will still
be a threat locally for some of these stronger thunderstorms and
heavier rainfall rates to impact the more populated areas of
southern FL which in this case will extend to the the southwest
coast including areas from Ft. Myers down through Naples. The
southeast coast of FL meanwhile from Miami down to Homestead will
still need to closely watch some of these slow-moving cells.

Rainfall rates of 2 to 4 inches/hour and storm totals locally
exceeding 5 inches are expected where any cells become anchored.
Earlier runs of the HRRR and RRFS were suggesting this near parts
of southwest FL in particular. As such, some areas of flash
flooding will be possible given the very high rainfall rates and
totals which may include some urban impacts.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6VYKq4ZHl918Q3pvMYHNoqpOeYvAl-jH0wrrSGBnRCSi1o3jC2LsBNc7NHfFUTvg-7RE= -pJF1ZBRxkXB7uyLw6uPMHo$ for graphic product...

ATTN...WFO...KEY...MFL...TBW...

ATTN...RFC...ALR...NWC...

LAT...LON 27018174 26468098 26118014 25657992 25178031=20
25298104 26088186 26738218=20

=3D =3D =3D
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