Red Flag Warning 1, NWS Great Falls, MT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
409 AM MDT Mon Jun 9 2014

.DISCUSSION...A progressive weather pattern will be in place
through the short term period. A short wave trough will move
through southern Alberta today with winds increasing across
Central Montana and a surface cool front pushing east of the
Continental Divide by late afternoon. Chance for precipitation
today is generally low but an isolated shower or thunderstorm can
not be ruled out late this afternoon through this evening. this
wave moves east overnight leaving a westerly flow aloft over the
state that will become cyclonically curved on Tuesday as a second,
deeper wave moves through the Pacific Northwest then swings
through Montana Tuesday evening. Chance of showers and
thunderstorms looks much better with this wave and have continued
the trend of increasing pops as this wave pushes through the
state. It does appear that thunderstorms will become rather
numerous by evening; however, the likelihood of strong to severe
storms appears low as CAPE remains generally below 500 J/kg and
bulk shear appears unfavorable for rotating storms. Cooler
temperatures can be expected for Wednesday with isolated to
scattered showers and thunderstorms. mpj

Wednesday night through Monday...A large scale zonal flow pattern
will continue to be the driving force over the bulk of the long
term forecast. Shortwave troughs with induced ridges will continue
to move through this westerly flow and will determine the
potential for shower activity throughout the week. A shortwave
ridge moving into the area will limit precipitation potential
Wednesday night and Thursday before the next shortwave trough
moves into the area Friday. Temperature are generally expected to
be near or slightly below seasonal averages...with Thursday likely
the warmest day of the long term period. Models once again are
starting to show a potential large scale pattern change towards
the end of the forecast period...unfortunately not all models have
the same solution and confidence is low at this point that any
particular solution is going to be close to reality by the time
next weekend occurs across Montana. Suk

&&

.AVIATION...
UPDATED 0440Z.
VFR conditions expected for the next 24 hours. High pressure early
in period will keep area dry. High pressure will give way to
approaching system from west Monday morning. West/southwest wind
with gusts near to over 20 kts...near to over 30 kts near Rocky
Mountain Front... will develop by the mid morning then continue
through remainder of afternoon as surface low tracks across eastern
Montana. With instability from approaching system and daytime
heating, isolated showers possible, mainly KHVR, KLWT and KBZN
locations with sites further west having lower chances of showers
due to influence of downslope winds. Wind to decrease Monday evening
as low moves off to east.

&&

.FIRE WEATHER...
For the Helena Valley, westerly winds of 10 to 20 mph with gusts
of 30 to 40 mph can be expected this afternoon and evening. Minimum
relative humidity will be between 15 an 20 percent. A lack of
precipitation has resulted in finer fuels in the Helena Valley
being much drier than is typical for early June. With the current
fuel conditions and expected warm, dry and windy conditions this
afternoon, the Fire Weather Watch has been upgraded to a Red Flag
Warning in effect from Noon until 10 PM MDT.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  77  44  70  43 /  10  10  30  50
CTB  73  42  66  40 /  10  20  40  60
HLN  81  49  75  46 /  10  10  30  30
BZN  79  44  74  42 /  10  10  30  40
WEY  71  35  71  33 /  10  10  40  20
DLN  78  45  74  42 /  10  10  20  20
HVR  79  45  72  43 /  20  20  20  70
LWT  75  43  67  41 /  10  20  30  70

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING from Noon today to 10 PM MDT this evening for the
Helena Valley in Central and Southern Lewis and Clark.

&&

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