Area Forecast Discussion
Issued by NWS Great Falls, MT
FXUS65 KTFX 252258
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
458 PM MDT Fri Jul 25 2014
This Afternoon into Tonight... With wind gusts continuing around
60 mph across parts of the Rocky Mountain Front and considering
that diurnal mixing is at a maximum through 6 or 7 PM, decided to
extend the High Wind Warning for the Northern Rocky Mountain Front
through 9 PM MDT. The main area of concern will be Logan Pass
which has consistently been reporting gusts near 60 mph so far
this afternoon. The gusty winds should drop off rapidly after 7 or
8 PM as diurnal mixing wanes.
In addition to the breezy westerly winds, afternoon RH values
near 20 percent have lead to critical fire weather conditions for
Fire Zones 113 and 115. Thus, will continue the Red Flag Warning
until midnight across these zones. Similar conditions exist to the
west but fuels are not as dry/cured in this area so felt a Red
Flag Warning was not necessary.
Saturday through Sunday...An upper-level ridge will begin to
build over the Northern Rockies through the weekend yielding dry
and seasonally warm conditions as well as light winds. Although
mid-level winds become southwesterly on Sunday, models are in
agreement on keeping monsoonal moisture to the south of Montana.
Sunday night through Friday...Montana will remain beneath an upper
level ridge for the entire forecast period. This pattern will lead
to mostly dry conditions with increasing temperatures through
mid-week as the ridge axis remains over the Northern Rocky
Mountains. Wild card in this pattern will be how much monsoonal
moisture will be able to work it`s way northward along the leading
edge of the ridge. Pattern suggests that isolated thunderstorm
activity could be possible in far Southwest Montana through much of
the period. However, the best chance for isolated convection to work
it`s way into Central Montana appears to be later in the week as
models depict a disturbance moving northward through the Great Basin
Wednesday and moving into Western Montana on Thursday. Confidence in
timing and coverage is low at this time, especially given the
strength of the upper ridge. Main impact during the upcoming week
will be the continued curing of fuels and the increasing likelihood
that despite the low chances for thunderstorm activity, any storms
that do form will be dry thereby increasing fire danger. mpj
High pressure will continue to provide dry and stable conditions.
Skies will remain clear. Surface winds will be gusty over the plains
but diminish during the evening. VFR conditions prevail.
A Red Flag Warning is in effect until Midnight for Zones 113 and
115. The combination of minimum relative humidity values around 20
percent and gusty west winds sustained at 15 to 25 mph with gusts
to 40 mph will create critical fire weather conditions.
.PRELIMINARY POINT TEMPS/POPS...
GTF 49 80 51 85 / 0 0 0 0
CTB 47 77 48 84 / 0 0 0 0
HLN 54 83 55 90 / 0 0 0 0
BZN 44 81 46 87 / 0 0 0 0
WEY 34 75 37 79 / 0 0 0 0
DLN 45 80 48 85 / 0 0 0 0
HVR 51 79 52 86 / 0 0 0 0
LWT 49 78 51 84 / 0 0 0 0
RED FLAG WARNING until Midnight MDT tonight Blaine...Chouteau...
HIGH WIND WARNING until 9 PM MDT this evening Northern Rocky