000
FXUS66 KOTX 190018
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
518 PM PDT Sat May 18 2013
.SYNOPSIS...
Scattered showers and isolated thunderstorms will develop again
this afternoon and evening. The greatest threat of thunder will
occur over the northeast corner of Washington and much of the
Idaho Panhandle. Precipitation chances will diminish a bit on
Sunday and by Monday most locations will be dry. This drying will
come to an abrupt end by Tuesday afternoon and into Wednesday as a
a very cool and wet upper level low parks itself over the Inland
Northwest. Steady, moderate precipitation will be possible
especially over northeast Washington and the northern Panhandle.
&&
.DISCUSSION...
Late afternoon update to the forecast for this evening. Added some
isolated thunderstorms across mainly Okanogan County to Ferry
County. LAPS data shows CAPE values up to around 400 J/kg and we
have already seen a handful of lightning strikes this afternoon
across this area. The thunderstorm threat will mainly only go
through until sunset. Once we lose our surface heating across
these areas, we shouldn`t retain enough instability for
thunderstorms to continue. Also added some isolated showers across the
basin as the next wave crosses the Cascades. Radar imagery does show
some weak echoes developing across the Moses Lake Area into the
Upper Columbia Basin. These showers are not expected to produce
much in the way of rainfall, but we could see around a hundredth
or so through this evening underneath these showers. The HRRR
model has the possibility for these showers reaching the Spokane
Area around 8:00 PM; however, the best forcing with this wave across
the basin will remain more over our southern zones, so not
expecting much from these showers once they get this far east into
the Spokane Area. /SVH
&&
.AVIATION...
00z TAFS: An upper level trough and weak disturbances embedded
within will aid in generating showers especially over the
mountains. Isolated thunderstorms will also be possible mainly
over the mountains north of the Columbia Basin though 03z this
evening. Westerly flow in the mid levels will lead to downslope
flow off the Cascades with dry conditions persisting at KEAT/KMWH.
TAF sites that receive showers could see low stratus forming after
15Z but confidence is low that conditions will fall below VFR for
any TAF site. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 45 66 46 72 52 75 / 10 20 10 0 0 20
Coeur d`Alene 45 65 44 71 47 75 / 10 30 20 0 0 30
Pullman 43 63 42 71 47 76 / 10 20 10 0 0 20
Lewiston 49 68 49 77 53 83 / 10 20 10 0 0 20
Colville 45 72 43 78 45 79 / 30 20 20 10 10 40
Sandpoint 43 65 42 71 44 75 / 10 50 30 10 10 30
Kellogg 44 60 46 69 50 74 / 10 40 30 10 10 20
Moses Lake 47 76 46 80 50 79 / 10 10 0 0 0 20
Wenatchee 49 73 49 78 53 74 / 10 0 0 0 0 20
Omak 45 74 43 77 46 76 / 50 10 10 0 0 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 182318
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
418 PM PDT Sat May 18 2013
.SYNOPSIS...
Scattered showers and isolated thunderstorms will develop again
this afternoon and evening. The greatest threat of thunder will
occur over the northeast corner of Washington and much of the
Idaho Panhandle. Precipitation chances will diminish a bit on
Sunday and by Monday most locations will be dry. This drying will
come to an abrupt end by Tuesday afternoon and into Wednesday as a
a very cool and wet upper level low parks itself over the Inland
Northwest. Steady, moderate precipitation will be possible
especially over northeast Washington and the northern Panhandle.
&&
.DISCUSSION...
Tonight and Sunday...An upper level trough along the Washington
and Oregon coast this afternoon will move inland tonight. Energy
from this system will split with one piece crossing the East
Slopes of the Cascades and moving into the Okanogan Highlands this
evening and then stalling in this area overnight. A combination of
this wave passing through this evening combined with low level
instability with surface based CAPE values of 100-300 J/KG should
support scattered showers over the Okanogan Highlands. A stray
lightning strike is also possible. These showers should begin to
die down overnight with the loss of daytime heating but with the
aforementioned wave stalling isolated showers may persist
overnight. Meanwhile drier air along the East Slopes of the
Cascades will keep showers isolated this evening despite the wave
passage. The southern piece will move south of the area into
Oregon. With the splitting nature this is not expected to produce
too much nocturnal shower activity but isolated coverage is
possible. Elsewhere mainly isolated showers through early this
evening before falling apart with the loss of daytime heating. On
Sunday a short wave ridge will be moving towards the Cascades but
residual moisture and daytime heating will result in another round
of showers mainly over north Idaho and northeast Washington. Also
just enough instability may be present over the northern mountains
with CAPE values as high as 400 J/KG for isolated afternoon
thunderstorms. JW
Sunday evening through Wednesday evening...Looks like this period
will begin on a dry and warm note as an upper level ridge
temporarily builds over the Inland NW. Residual instability could
still trigger some showers or even a thunderstorm early over the
extreme northeast Washington and the northern Idaho but the odds
aren`t great as warmer air aloft begins to cap the depth of the
potential convection. Precipitation chances look like they will
diminish even further on Monday as the 500 mb ridge axis shifts
toward the WA/ID border...with plenty of dry air moving into the
850-500 mb layer. Although there still could be enough instability
for some cumulus clouds over the northern mountains...most
locations should see mostly sunny conditions and temperatures
returning to near normal or slightly warmer than normal levels.
Just how long the ridge will retain its grip on the region is the
tough question to answer. All model solutions gradually replace
the ridge with a very deep and unusually cool upper level low
sometime on Tuesday as it dives into the region from the
northwest. The ECMWF takes the center of the the central
Washington coast by late Tuesday afternoon and subsequently shoves
a strong cold front through the Cascades and into the central
Columbia Basin. Meanwhile the GFS and GEM models are at least 6-12
hrs slower. The latest ECMWF is a fast outlier...however it has
some support from its ensemble. The timing of the front will have
a big impact on high temperatures for Tuesday. Suffice it to
say...the eastern third of the forecast area looks like it will
see significant warming compared to Monday with readings surging
into the mid 70s to lower 80s...whereas the western areas will
have a tougher time reaching values that warm as clouds and the
threat of precipitation moves in ahead of the cold front. Another
issue will be threat of deep convection and possibly some strong
thunderstorms as the heat and significant moisture advection
coincides with moderate upper level divergence ahead of the upper
level jet. The situation is somewhat similar to what we saw last
Monday...however the upper level forcing looks weaker with the
core of the 500 mb energy diving south of our forecast area. Of
all solutions...the NAM looks most favorable for big thunderstorms
with SBCapes reaching 500-800 j/kg with little if any CIN over NE
WA and N ID. The GFS meanwhile is much less impressive. Hopefully
there will be more resolution as the event nears.
Once the front passes and the core of the low shifts into the
region...we will be faced with much cooler and wetter
weather...and this pattern will persist for quite some time as the
low takes up residence over the area. In all cases...it appears
the front will move quite slowly and bring widespread
precipitation...including locally heavy precipitation with the
greatest threat over the northern third of Washington and into the
Idaho Panhandle. How much impact this will have on area rivers
remains questionable as the snow levels will fall precipitously
minimizing much of the snow melt contribution. The rivers most
susceptible to the significant rises will be those over north
Idaho....especially considering some model solutions are placing
the heaviest precipitation to our east and north. fx
Wednesday night through Saturday...Models remain in agreement with
the large scale pattern depicting an upper level low centered
somewhere over the Pacific Northwest during the extended forecast
period. The finer detains of the exact track of the vorticity lobes
have yet to come into sharper focus. Confidence is high that we will
see lots of clouds and cooler than normal daytime temperatures, but
exactly where, when and how much precipitation will fall across the
Inland Northwest will have to wait until the event nears. PoPs
continue the above climo trend while temps will remain below
seasonal normals. /Kelch
&&
.AVIATION...
00z TAFS: An upper level trough and weak disturbances embedded
within will aid in generating showers especially over the
mountains. Isolated thunderstorms will also be possible mainly
over the mountains north of the Columbia Basin though 03z this
evening. Westerly flow in the mid levels will lead to downslope
flow off the Cascades with dry conditions persisting at KEAT/KMWH.
TAF sites that receive showers could see low stratus forming after
15Z but confidence is low that conditions will fall below VFR for
any TAF site. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 45 66 46 72 52 75 / 20 20 10 0 0 20
Coeur d`Alene 45 65 44 71 47 75 / 20 30 20 0 0 30
Pullman 43 63 42 71 47 76 / 20 20 10 0 0 20
Lewiston 49 68 49 77 53 83 / 10 20 10 0 0 20
Colville 45 72 43 78 45 79 / 30 20 20 10 10 40
Sandpoint 43 65 42 71 44 75 / 30 50 30 10 10 30
Kellogg 44 60 46 69 50 74 / 20 40 30 10 10 20
Moses Lake 47 76 46 80 50 79 / 10 10 0 0 0 20
Wenatchee 49 73 49 78 53 74 / 10 0 0 0 0 20
Omak 45 74 43 77 46 76 / 20 10 10 0 0 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 182158
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
258 PM PDT Sat May 18 2013
.SYNOPSIS...
Scattered showers and isolated thunderstorms will develop again
this afternoon and evening. The greatest threat of thunder will
occur over the northeast corner of Washington and much of the
Idaho Panhandle. Precipitation chances will diminish a bit on
Sunday and by Monday most locations will be dry. This drying will
come to an abrupt end by Tuesday afternoon and into Wednesday as a
a very cool and wet upper level low parks itself over the Inland
Northwest. Steady, moderate precipitation will be possible
especially over northeast Washington and the northern Panhandle.
&&
.DISCUSSION...
Tonight and Sunday...An upper level trough along the Washington
and Oregon coast this afternoon will move inland tonight. Energy
from this system will split with one piece crossing the East
Slopes of the Cascades and moving into the Okanogan Highlands this
evening and then stalling in this area overnight. A combination of
this wave passing through this evening combined with low level
instability with surface based CAPE values of 100-300 J/KG should
support scattered showers over the Okanogan Highlands. A stray
lightning strike is also possible. These showers should begin to
die down overnight with the loss of daytime heating but with the
aforementioned wave stalling isolated showers may persist
overnight. Meanwhile drier air along the East Slopes of the
Cascades will keep showers isolated this evening despite the wave
passage. The southern piece will move south of the area into
Oregon. With the splitting nature this is not expected to produce
too much nocturnal shower activity but isolated coverage is
possible. Elsewhere mainly isolated showers through early this
evening before falling apart with the loss of daytime heating. On
Sunday a short wave ridge will be moving towards the Cascades but
residual moisture and daytime heating will result in another round
of showers mainly over north Idaho and northeast Washington. Also
just enough instability may be present over the northern mountains
with CAPE values as high as 400 J/KG for isolated afternoon
thunderstorms. JW
Sunday evening through Wednesday evening...Looks like this period
will begin on a dry and warm note as an upper level ridge
temporarily builds over the Inland NW. Residual instability could
still trigger some showers or even a thunderstorm early over the
extreme northeast Washington and the northern Idaho but the odds
aren`t great as warmer air aloft begins to cap the depth of the
potential convection. Precipitation chances look like they will
diminish even further on Monday as the 500 mb ridge axis shifts
toward the WA/ID border...with plenty of dry air moving into the
850-500 mb layer. Although there still could be enough instability
for some cumulus clouds over the northern mountains...most
locations should see mostly sunny conditions and temperatures
returning to near normal or slightly warmer than normal levels.
Just how long the ridge will retain its grip on the region is the
tough question to answer. All model solutions gradually replace
the ridge with a very deep and unusually cool upper level low
sometime on Tuesday as it dives into the region from the
northwest. The ECMWF takes the center of the the central
Washington coast by late Tuesday afternoon and subsequently shoves
a strong cold front through the Cascades and into the central
Columbia Basin. Meanwhile the GFS and GEM models are at least 6-12
hrs slower. The latest ECMWF is a fast outlier...however it has
some support from its ensemble. The timing of the front will have
a big impact on high temperatures for Tuesday. Suffice it to
say...the eastern third of the forecast area looks like it will
see significant warming compared to Monday with readings surging
into the mid 70s to lower 80s...whereas the western areas will
have a tougher time reaching values that warm as clouds and the
threat of precipitation moves in ahead of the cold front. Another
issue will be threat of deep convection and possibly some strong
thunderstorms as the heat and significant moisture advection
coincides with moderate upper level divergence ahead of the upper
level jet. The situation is somewhat similar to what we saw last
Monday...however the upper level forcing looks weaker with the
core of the 500 mb energy diving south of our forecast area. Of
all solutions...the NAM looks most favorable for big thunderstorms
with SBCapes reaching 500-800 j/kg with little if any CIN over NE
WA and N ID. The GFS meanwhile is much less impressive. Hopefully
there will be more resolution as the event nears.
Once the front passes and the core of the low shifts into the
region...we will be faced with much cooler and wetter
weather...and this pattern will persist for quite some time as the
low takes up residence over the area. In all cases...it appears
the front will move quite slowly and bring widespread
precipitation...including locally heavy precipitation with the
greatest threat over the northern third of Washington and into the
Idaho Panhandle. How much impact this will have on area rivers
remains questionable as the snow levels will fall precipitously
minimizing much of the snow melt contribution. The rivers most
susceptible to the significant rises will be those over north
Idaho....especially considering some model solutions are placing
the heaviest precipitation to our east and north. fx
Wednesday night through Saturday...Models remain in agreement with
the large scale pattern depicting an upper level low centered
somewhere over the Pacific Northwest during the extended forecast
period. The finer detains of the exact track of the vorticity lobes
have yet to come into sharper focus. Confidence is high that we will
see lots of clouds and cooler than normal daytime temperatures, but
exactly where, when and how much precipitation will fall across the
Inland Northwest will have to wait until the event nears. PoPs
continue the above climo trend while temps will remain below
seasonal normals. /Kelch
&&
.AVIATION...
18z TAFS: An upper level trough and weak disturbances embedded
within will aid in generating showers especially over the
mountains. Isolated thunderstorms will also be possible mainly over
the mountains north of the Columbia Basin from 20z today through 03z
this evening. Westerly flow in the mid levels will lead to downslope
flow off the Cascades with dry conditions persisting at KEAT/KMWH.
CIGS are expected to be primarily VFR...with brief MVFR conditions
possible around KSFF/KCOE through 20z. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 45 66 46 72 52 75 / 20 20 10 0 0 20
Coeur d`Alene 45 65 44 71 47 75 / 20 30 20 0 0 30
Pullman 43 63 42 71 47 76 / 20 20 10 0 0 20
Lewiston 49 68 49 77 53 83 / 10 20 10 0 0 20
Colville 45 72 43 78 45 79 / 30 20 20 10 10 40
Sandpoint 43 65 42 71 44 75 / 30 50 30 10 10 30
Kellogg 44 60 46 69 50 74 / 20 40 30 10 10 20
Moses Lake 47 76 46 80 50 79 / 10 10 0 0 0 20
Wenatchee 49 73 49 78 53 74 / 10 0 0 0 0 20
Omak 45 74 43 77 46 76 / 20 10 10 0 0 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 181754
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1054 AM PDT Sat May 18 2013
.SYNOPSIS...
Scattered showers and isolated thunderstorms will develop again
this afternoon and evening. The greatest threat of thunder will
occur over the northeast corner of Washington and much of the
Idaho Panhandle. Precipitation chances will diminish a bit on
Sunday and by Monday most locations will be dry. This drying will
come to an abrupt end by Tuesday afternoon and into Wednesday as a
a very cool and wet upper level low parks itself over the Inland
Northwest. Steady, moderate precipitation will be possible
especially over northeast Washington and the northern Panhandle.
&&
.DISCUSSION...
Water vapor satellite imagery shows a mid level wave tracking
across Eastern Washington and North Idaho this morning. This
combined with mid level instability will continue to generate
showers this morning over the Okanogan Valley and Highlands,
Northeast Washington Mountains, and over North Idaho mainly north
of Lewiston. For this afternoon into the evening hours another
wave will track across the region which combined with afternoon
heating will generate more showers especially over the northern
mountains where high dew points in the upper 40s and lower 50s
exist due to the shower activity this morning. The forecast for
this morning has been updated to increase shower wording in the
valleys north of Highway 2 in Washington...and over North Idaho.
Also made some sky cover adjustments to show more cloud cover this
morning...and to increase clouds over Central Washington this
afternoon as the next wave crosses the Cascades. These clouds will
keep high temperatures down more then previously expected and highs
were adjusted downward mainly areas north of a line from Omak to
Spokane to Kellogg. JW
&&
.AVIATION...
18z TAFS: An upper level trough and weak disturbances embedded
within will aid in generating showers especially over the
mountains. Isolated thunderstorms will also be possible mainly over
the mountains north of the Columbia Basin from 20z today through 03z
this evening. Westerly flow in the mid levels will lead to downslope
flow off the Cascades with dry conditions persisting at KEAT/KMWH.
CIGS are expected to be primarily VFR...with brief MVFR conditions
possible around KSFF/KCOE through 20z. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 45 66 46 70 49 / 40 20 20 10 0 10
Coeur d`Alene 62 44 64 43 69 45 / 60 30 30 20 0 10
Pullman 62 43 63 41 69 45 / 20 20 20 10 0 10
Lewiston 69 49 70 48 76 51 / 20 20 20 10 0 10
Colville 66 44 73 43 76 44 / 70 40 30 20 10 10
Sandpoint 60 43 64 42 69 43 / 70 40 40 30 10 10
Kellogg 58 44 60 45 67 46 / 60 30 40 40 10 10
Moses Lake 72 47 76 45 79 48 / 10 10 10 0 0 10
Wenatchee 69 48 72 49 76 51 / 10 10 10 0 0 10
Omak 69 43 74 42 77 46 / 50 20 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 181531
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
831 AM PDT Sat May 18 2013
.SYNOPSIS...
Scattered showers and isolated thunderstorms will develop again
this afternoon and evening. The greatest threat of thunder will
occur over the northeast corner of Washington and much of the
Idaho Panhandle. Precipitation chances will diminish a bit on
Sunday and by Monday most locations will be dry. This drying will
come to an abrupt end by Tuesday afternoon and into Wednesday as a
a very cool and wet upper level low parks itself over the Inland
Northwest. Steady, moderate precipitation will be possible
especially over northeast Washington and the northern Panhandle.
&&
.DISCUSSION...
Water vapor satellite imagery shows a mid level wave tracking
across Eastern Washington and North Idaho this morning. This
combined with mid level instability will continue to generate
showers this morning over the Okanogan Valley and Highlands,
Northeast Washington Mountains, and over North Idaho mainly north
of Lewiston. For this afternoon into the evening hours another
wave will track across the region which combined with afternoon
heating will generate more showers especially over the northern
mountains where high dew points in the upper 40s and lower 50s
exist due to the shower activity this morning. The forecast for
this morning has been updated to increase shower wording in the
valleys north of Highway 2 in Washington...and over North Idaho.
Also made some sky cover adjustments to show more cloud cover this
morning...and to increase clouds over Central Washington this
afternoon as the next wave crosses the Cascades. Current forecast
high temperatures may be slightly on the high side over Northeast
Washington and North Idaho based on latest guidance and may update
later to lower highs. JW
&&
.AVIATION...
12Z TAFS: Disturbances moving through the somewhat unstable
atmosphere over the aviation area will allow for elevated forced
showers during the overnight and early morning hours along with
surface based convection coupled with peak heating in the near
afternoon and evening hours...but all in all VFR conditions
are expected to prevail.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 65 45 66 46 70 49 / 40 20 20 10 0 10
Coeur d`Alene 64 44 64 43 69 45 / 60 30 30 20 0 10
Pullman 63 43 63 41 69 45 / 20 20 20 10 0 10
Lewiston 70 49 70 48 76 51 / 20 20 20 10 0 10
Colville 70 44 73 43 76 44 / 70 40 30 20 10 10
Sandpoint 64 43 64 42 69 43 / 70 40 40 30 10 10
Kellogg 60 44 60 45 67 46 / 60 30 40 40 10 10
Moses Lake 73 47 76 45 79 48 / 10 10 10 0 0 10
Wenatchee 68 48 72 49 76 51 / 10 10 10 0 0 10
Omak 71 43 74 42 77 46 / 50 20 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 181129
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
426 AM PDT Sat May 18 2013
.SYNOPSIS...
Scattered showers and isolated thunderstorms will develop again
this afternoon and evening. The greatest threat of thunder will
occur over the northeast corner of Washington and much of the
Idaho Panhandle. Precipitation chances will diminish a bit on
Sunday and by Monday most locations will be dry. This drying will
come to an abrupt end by Tuesday afternoon and into Wednesday as a
a very cool and wet upper level low parks itself over the Inland
Northwest. Steady, moderate precipitation will be possible
especially over northeast Washington and the northern Panhandle.
&&
.DISCUSSION...
Today through Sunday...Low pressure trof containing typical spring
somewhat unstable air-mass along with nuisance mesoscale shortwaves
rotating through and around it remains. The subtle change is that
the axis of the trof moves east and as a result higher pressure
approaches from the west and gets in closer proximity with time.
The result of such a scenario described above is continued clutter
of moderate to low pops the show a decreasing but not disappearing
trend into Sunday to account for not only surface based convection
in the afternoon and evening but also some minor elevated
convection during the overnight and early morning hours associated
with these nuisance small scale shortwaves. Precipitation amounts
can be best conveyed by describing this convection as hit and miss
showers and even more remote weak thunderstorms. With the eastward
migration of the trof axis height rises moving in from the west
suggest an ever so slight and not entirely homogeneous warming
trend in max temperature going into Sunday. /Pelatti
Sunday night through Monday night: Evening showers will taper off
over north Idaho within the vicinity of the upper trough axis.
Meanwhile a high pressure ridge will nose in over eastern
Washington. A few more instability showers or thunderstorms are
possible Monday afternoon and evening over the higher mountains of
the Idaho Panhandle as the weaken trough axis slowly exits the
region. Temperatures will be close to seasonal normals.
Tuesday through Thursday morning: The weather will be focused on the
presence of a deep upper level low. This Pacific low will swing
toward the WA coast Tuesday morning with light showers spread east
of the Cascades by Tuesday afternoon. This is slightly slower than
previous forecast and have indicated this in the forecast and kept
seasonal temperatures through Tuesday. Then as the upper low
center slowly moves inland, the impact will be in the form of a
deformation band of steady moderate precipitation which will shift
across eastern Washington and into north Idaho Tuesday night into
Wednesday. There are a few model differences on the track and
placement of this low center, which will effect the type and
intensity of the precipitation, but for the part did show the
low center meandering on either side of the Cascades. Areas
closer to the low center will encounter more convective
precipitation and lower snow levels down to near 4k ft. The
majority of the medium range models show the best chance of the
steady moderate precipitation from the deformation band will be
across southern BC and into the Canadian Rockies from Wednesday
night through Thursday morning. This will impact runoff and
mountain snow melt from the headwaters of several Inland Northwest
rivers, including the Okanogan, Kootenai, Kettle and Moyie.
Overall, anticipate cooler temperatures by Thursday with a threat
of near freezing conditions by early Thursday morning. /rfox
Thursday Afternoon through Friday Night: This time frame will be the
continuation of the previous period as the stubborn low pressure
system will continue to influence our weather pattern. With the
low in control we will see our temperatures fall to below normal
and slowly creep back towards normal by the end of the period.
Models are in decent agreement given the time frame in keeping the
low pivoting around the Pacific NW region...but the precise
location still remains uncertain given model discrepancies. Longer
range models have the center of the low scattered throughout the
region so above normal climo POPs was the trend in the extended
with the unsettled weather pattern in place. As we progress models
should align better giving a better idea as to where precip will
be more likely. As temps do start to reach more normal values
towards the weekend snow levels will be on the rise...which will
allow for greater runoff contribution to streams. Overall given
current model runs it appears that the brunt of the precip will
have already past but we will need to continue to watch rivers and
streams for any flooding concerns. Even given the far
extended...models are still reluctant to move this system out of
the region so it looks like we will remain in this unsettled pattern
for quite some time. /Fliehman
&&
.AVIATION...
12Z TAFS: Disturbances moving through the somewhat unstable
atmosphere over the aviation area will allow for elevated forced
showers during the overnight and early morning hours along with
surface based convection coupled with peak heating in the near
afternoon and evening hours...but all in all VFR conditions
are expected to prevail.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 65 45 66 46 70 49 / 40 20 20 10 0 10
Coeur d`Alene 64 44 64 43 69 45 / 40 30 30 20 0 10
Pullman 63 43 63 41 69 45 / 20 20 20 10 0 10
Lewiston 70 49 70 48 76 51 / 20 20 20 10 0 10
Colville 70 44 73 43 76 44 / 50 40 30 20 10 10
Sandpoint 64 43 64 42 69 43 / 40 40 40 30 10 10
Kellogg 60 44 60 45 67 46 / 40 30 40 40 10 10
Moses Lake 73 47 76 45 79 48 / 10 10 10 0 0 10
Wenatchee 68 48 72 49 76 51 / 10 10 10 0 0 10
Omak 71 43 74 42 77 46 / 40 20 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 180930
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
230 AM PDT Sat May 18 2013
.SYNOPSIS...
Scattered showers and isolated thunderstorms will develop again
this afternoon and evening. The greatest threat of thunder will
occur over the northeast corner of Washington and much of the
Idaho Panhandle. Precipitation chances will diminish a bit on
Sunday and by Monday most locations will be dry. This drying will
come to an abrupt end by Tuesday afternoon and into Wednesday as a
a very cool and wet upper level low parks itself over the Inland
Northwest. Steady, moderate precipitation will be possible
especially over northeast Washington and the northern Panhandle.
&&
.DISCUSSION...
Today through Sunday...Low pressure trof containing typical spring
somewhat unstable air-mass along with nuisance mesoscale shortwaves
rotating through and around it remains. The subtle change is that
the axis of the trof moves east and as a result higher pressure
approaches from the west and gets in closer proximity with time.
The result of such a scenario described above is continued clutter
of moderate to low pops the show a decreasing but not disappearing
trend into Sunday to account for not only surface based convection
in the afternoon and evening but also some minor elevated
convection during the overnight and early morning hours associated
with these nuisance small scale shortwaves. Precipitation amounts
can be best conveyed by describing this convection as hit and miss
showers and even more remote weak thunderstorms. With the eastward
migration of the trof axis height rises moving in from the west
suggest an ever so slight and not entirely homogeneous warming
trend in max temperature going into Sunday. /Pelatti
Sunday night through Monday night: Evening showers will taper off
over north Idaho within the vicinity of the upper trough axis.
Meanwhile a high pressure ridge will nose in over eastern
Washington. A few more instability showers or thunderstorms are
possible Monday afternoon and evening over the higher mountains of
the Idaho Panhandle as the weaken trough axis slowly exits the
region. Temperatures will be close to seasonal normals.
Tuesday through Thursday morning: The weather will be focused on the
presence of a deep upper level low. This Pacific low will swing
toward the WA coast Tuesday morning with light showers spread east
of the Cascades by Tuesday afternoon. This is slightly slower than
previous forecast and have indicated this in the forecast and kept
seasonal temperatures through Tuesday. Then as the upper low
center slowly moves inland, the impact will be in the form of a
deformation band of steady moderate precipitation which will shift
across eastern Washington and into north Idaho Tuesday night into
Wednesday. There are a few model differences on the track and
placement of this low center, which will effect the type and
intensity of the precipitation, but for the part did show the
low center meandering on either side of the Cascades. Areas
closer to the low center will encounter more convective
precipitation and lower snow levels down to near 4k ft. The
majority of the medium range models show the best chance of the
steady moderate precipitation from the deformation band will be
across southern BC and into the Canadian Rockies from Wednesday
night through Thursday morning. This will impact runoff and
mountain snow melt from the headwaters of several Inland Northwest
rivers, including the Okanogan, Kootenai, Kettle and Moyie.
Overall, anticipate cooler temperatures by Thursday with a threat
of near freezing conditions by early Thursday morning. /rfox
Thursday Afternoon through Friday Night: This time frame will be the
continuation of the previous period as the stubborn low pressure
system will continue to influence our weather pattern. With the
low in control we will see our temperatures fall to below normal
and slowly creep back towards normal by the end of the period.
Models are in decent agreement given the time frame in keeping the
low pivoting around the Pacific NW region...but the precise
location still remains uncertain given model discrepancies. Longer
range models have the center of the low scattered throughout the
region so above normal climo POPs was the trend in the extended
with the unsettled weather pattern in place. As we progress models
should align better giving a better idea as to where precip will
be more likely. As temps do start to reach more normal values
towards the weekend snow levels will be on the rise...which will
allow for greater runoff contribution to streams. Overall given
current model runs it appears that the brunt of the precip will
have already past but we will need to continue to watch rivers and
streams for any flooding concerns. Even given the far
extended...models are still reluctant to move this system out of
the region so it looks like we will remain in this unsettled pattern
for quite some time. /Fliehman
&&
.AVIATION...
06Z TAFS: A slow moving system beginning to push into southern WA
late this evening will continue to produce isolated to scattered
rain showers across the region tonight into tomorrow afternoon. Cigs
are expected to remain above 4 kft agl with vfr conditions through
Saturday afternoon. Winds are expected to pick up a bit out of the
west late Saturday afternoon at KEAT with gusts up to 30 mph
possible. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 65 45 66 46 70 49 / 40 20 20 10 0 10
Coeur d`Alene 64 44 64 43 69 45 / 40 30 30 20 0 10
Pullman 63 43 63 41 69 45 / 20 20 20 10 0 10
Lewiston 70 49 70 48 76 51 / 20 20 20 10 0 10
Colville 70 44 73 43 76 44 / 50 40 30 20 10 10
Sandpoint 64 43 64 42 69 43 / 40 40 40 30 10 10
Kellogg 60 44 60 45 67 46 / 40 30 40 40 10 10
Moses Lake 73 47 76 45 79 48 / 10 10 10 0 0 10
Wenatchee 68 48 72 49 76 51 / 10 10 10 0 0 10
Omak 71 43 74 42 77 46 / 40 20 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 180547
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1047 PM PDT Fri May 17 2013
.SYNOPSIS...
A series of weak weather disturbances coupled with an unstable air
mass will result in occasional showers and isolated thunderstorms
through most of the weekend. The greatest threat of thunder will
occur over the northeast corner of Washington and much of the
Idaho Panhandle. Precipitation chances will diminish a bit on
Sunday and by Monday most locations will be dry. This drying will
come to an abrupt end by Tuesday and into the middle of next week
as a very cool and wet upper level low parks over the Inland
Northwest. Moderate to locally heavy precipitation will be
possible especially over northeast Washington and the northern
Panhandle.
&&
.DISCUSSION...
Forecast from the afternoon package is largely on track. The upper
level shortwave trough of lower pressure responsible for the
showers across the region is pivoting into northeast Oregon up
into southwestern WA this evening. Scattered showers are expected
to continue across much of the region through the late evening
hours and then slowly push across northern portions of eastern WA
and over the ID Panhandle for the overnight hours. I did keep a
mention of some isolated thunderstorms across the Central
Panhandle Mountains and Northern Panhandle through the late
evening hours as we continue to get a few lightning strikes from
some of the stronger cells across these areas. We may see a strike
or two after about 1100 PM tonight, but instability aloft is
fairly weak for much in the way of thunderstorms to continue
through the nighttime hours. /SVH
&&
.AVIATION...
06Z TAFS: A slow moving system beginning to push into southern WA
late this evening will continue to produce isolated to scattered
rain showers across the region tonight into tomorrow afternoon. Cigs
are expected to remain above 4 kft agl with vfr conditions through
Saturday afternoon. Winds are expected to pick up a bit out of the
west late Saturday afternoon at KEAT with gusts up to 30 mph
possible. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 65 45 66 45 69 / 50 40 20 20 10 10
Coeur d`Alene 47 64 44 64 44 68 / 50 40 30 30 20 10
Pullman 47 63 43 63 42 68 / 20 20 20 20 10 0
Lewiston 51 70 49 70 48 75 / 20 20 20 20 10 0
Colville 47 70 44 73 43 75 / 40 50 40 30 20 10
Sandpoint 46 64 43 64 42 68 / 60 40 40 40 30 10
Kellogg 47 60 44 59 45 66 / 70 40 30 40 40 10
Moses Lake 50 73 47 76 46 77 / 30 10 10 10 0 0
Wenatchee 50 68 48 72 48 75 / 20 10 10 10 0 0
Omak 48 71 43 74 42 75 / 30 40 20 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 180330
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
830 PM PDT Fri May 17 2013
.SYNOPSIS...
A series of weak weather disturbances coupled with an unstable air
mass will result in occasional showers and isolated thunderstorms
through most of the weekend. The greatest threat of thunder will
occur over the northeast corner of Washington and much of the
Idaho Panhandle. Precipitation chances will diminish a bit on
Sunday and by Monday most locations will be dry. This drying will
come to an abrupt end by Tuesday and into the middle of next week
as a very cool and wet upper level low parks over the Inland
Northwest. Moderate to locally heavy precipitation will be
possible especially over northeast Washington and the northern
Panhandle.
&&
.DISCUSSION...
Forecast from the afternoon package is largely on track. The upper
level shortwave trough of lower pressure responsible for the
showers across the region is pivoting into northeast Oregon up
into southwestern WA this evening. Scattered showers are expected
to continue across much of the region through the late evening
hours and then slowly push across northern portions of eastern WA
and over the ID Panhandle for the overnight hours. I did keep a
mention of some isolated thunderstorms across the Central
Panhandle Mountains and Northern Panhandle through the late
evening hours as we continue to get a few lightning strikes from
some of the stronger cells across these areas. We may see a strike
or two after about 1100 PM tonight, but instability aloft is
fairly weak for much in the way of thunderstorms to continue
through the nighttime hours. /SVH
&&
.AVIATION...
00Z TAFS: Widely scattered showers will affect most TAF sites
through 03Z. Isold -tsra will be possible but the threat is too
low to include in TAF forecast. Surface based convection will
dissipate after 03z but a weak midlevel wave lifting through the
region will bring the potential for nocturnal showers mainly east
of Moses Lake through the overnight period. Afternoon convection
will develop again after 18Z, but coverage will be spotty. /Kelch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 65 45 66 45 69 / 50 40 20 20 10 10
Coeur d`Alene 47 64 44 64 44 68 / 50 40 30 30 20 10
Pullman 47 63 43 63 42 68 / 20 20 20 20 10 0
Lewiston 51 70 49 70 48 75 / 20 20 20 20 10 0
Colville 47 70 44 73 43 75 / 40 50 40 30 20 10
Sandpoint 46 64 43 64 42 68 / 60 40 40 40 30 10
Kellogg 47 60 44 59 45 66 / 70 40 30 40 40 10
Moses Lake 50 73 47 76 46 77 / 30 10 10 10 0 0
Wenatchee 50 68 48 72 48 75 / 20 10 10 10 0 0
Omak 48 71 43 74 42 75 / 30 40 20 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 172323
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
423 PM PDT Fri May 17 2013
.SYNOPSIS...
A series of weak weather disturbances coupled with an unstable air
mass will result in occasional showers and isolated thunderstorms
through most of the weekend. The greatest threat of thunder will
occur over the northeast corner of Washington and much of the
Idaho Panhandle. Precipitation chances will diminish a bit on
Sunday and by Monday most locations will be dry. This drying will
come to an abrupt end by Tuesday and into the middle of next week
as a very cool and wet upper level low parks over the Inland
Northwest. Moderate to locally heavy precipitation will be
possible especially over northeast Washington and the northern
Panhandle.
&&
.DISCUSSION...
Tonight and Saturday: The Inland NW remains under a broad
upper-level trof that extends from the Gulf of AK to the
southwestern US. Afternoon heating has destabilized the air mass
and resulted in widely scattered showers which are rotating
cyclonically across the region. Given the lack of wind shear,
these storms are pulsing or going up quickly...then collapsing
just as quick but isolated lightning strikes have been observed
over multiple locations such as Colville...Nespelem...Methow
Valley...and Mission Ridge. The main threats with most activity
will be brief downpours...cloud to ground lightning strikes... and
pea size hail. A majority of this activity will dissipate with
sunset but there are some exceptions. Water vapor imagery in
conjunction with short-term model data clearly shows a shortwave
trof axis extending from the Puget Sound S/SE to the Tri-Cities.
As this boundary lifts N/NE overnight...we anticipate elevated
showers to continue through the night across portions of Ern WA
and Nrn ID...generally north and east of a line from Grand Coulee
to Pomeroy and some locations that miss out on surface based
convection this afternoon over Nrn ID and far NE WA may get a
renewed chance with the nocturnal activity.
Generally a repeat for Saturday`s weather with diurnally driven
showers and isolated thunder forming over the higher terrain
early then expanding into the Basin through the late afternoon.
Slightly better mixing and some drying behind this evening`s trof
passage should lower the threat for the southwestern Basin but
with a secondary shortwave trof already closing in on 130W and
expected to drop in northern Oregon Saturday afternoon...not so
sure these locations will experience a completely dry day.
Temperatures will remain near to slightly below seasonal
readings...highly dependent on whether a rain shower impacts the
location or not. /sb
Saturday evening through Tuesday evening...The model solutions are
in very good agreement that the next in a series of upper level
troughs will move into the region beginning late Saturday and
drifting slowly east/southeast toward central Idaho on Sunday.
Although this system will weaken steadily as it drifts through the
region...it will have a slight negative tilt as well. This
negative tilt is usually a good sign that the area will be subject
to convection deep enough to support thunderstorms and this will
likely be no exception. However with the base of the trough
expected to dig steadily south of the forecast area...much of the
upper level divergence and lift will remain out of the area as
well. Looks like most of the precipitation threat will occur over
the eastern half of the forecast area and will likely persist into
Sunday evening. By Monday...the area will begin to see shortwave
ridging accompanied by an intrusion of much drier air in the lower
and middle atmosphere. This should bring dry weather to most if
not all locations with the only exception occurring over the
extreme eastern Panhandle.
The brief lull in the precipitation will come to an end sometime on
Tuesday as a very deep upper level low has its sights set on much
of the Pacific Northwest. By Tuesday afternoon...there is good
model agreement that the center of a 540dm 500 mb low will be
parked just off the Washington coast. This places much of our
forecast area under deep southerly flow and an increasing threat
of precipitation. Precipitable water values will rapidly climb
toward .75 inches which is roughly 150 percent of the seasonal
normal. As the moisture moves in we expect to see a well-defined
band of precipitation develop ahead of a slow-moving cold front.
While precipitation from the front may have a tough time amounting
to much in the lee of the Cascades...it will likely intensify as
it tracks into the eastern half of the Columbia Basin on its way
toward the Idaho Panhandle. The big question is how quickly will
the front track into the Panhandle. The slower it moves...the
better chance there will be for deep convection firing ahead of
the front...while the faster would likely inhibit the chances. GFS
CAPE forecasts place values around 1000-1500 j/kg with very little
CIN which would support a chance of strong thunderstorms. We will
wait and see if there is some consistency between model runs
before jumping into this solution. While the threat of strong
thunderstorms remains questionable...there is a much better chance
of seeing moderate precipitation especially near the Canadian
border. fx
Tuesday night through Friday...wet and unseasonably cool conditions
will be the main story for the extended forecast period. Medium
range models are in good agreement on an upper level low settling
over the region with widespread precipitation across the Inland
Northwest for Tuesday night and Wednesday. There is some spread in
the evolution of the low regarding the splitting of the energy and
where the vorticity lobes will track by Friday. With increasing
confidence in the mid-week forecast, PoPs have been increased and
daytime temperatures have been lowered, especially for Wednesday
when the upper low will be overhead. Fortunately for flooding
concerns, snow levels will be lower, keeping much of the higher
elevation precip as snow rather than rain/runoff. Precip at mid and
lower elevations will still be adding to runoff into streams and
rivers that are already running high. /Kelch
&&
.AVIATION...
00Z TAFS: Widely scattered showers will affect most TAF sites
through 03Z. Isold -tsra will be possible but the threat is too
low to include in TAF forecast. Surface based convection will
dissipate after 03z but a weak midlevel wave lifting through the
region will bring the potential for nocturnal showers mainly east
of Moses Lake through the overnight period. Afternoon convection
will develop again after 18Z, but coverage will be spotty. /Kelch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 65 45 66 45 69 / 70 40 20 20 10 10
Coeur d`Alene 46 64 44 64 44 68 / 60 40 30 30 20 10
Pullman 47 63 43 63 42 68 / 40 20 20 20 10 0
Lewiston 51 70 49 70 48 75 / 40 20 20 20 10 0
Colville 47 70 44 73 43 75 / 50 50 40 30 20 10
Sandpoint 46 64 43 64 42 68 / 50 40 40 40 30 10
Kellogg 46 60 44 59 45 66 / 60 40 30 40 40 10
Moses Lake 50 73 47 76 46 77 / 30 10 10 10 0 0
Wenatchee 50 68 48 72 48 75 / 40 10 10 10 0 0
Omak 48 71 43 74 42 75 / 50 40 20 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 172205
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
305 PM PDT Fri May 17 2013
.SYNOPSIS...
A series of weak weather disturbances coupled with an unstable air
mass will result in occasional showers and isolated thunderstorms
through most of the weekend. The greatest threat of thunder will
occur over the northeast corner of Washington and much of the
Idaho Panhandle. Precipitation chances will diminish a bit on
Sunday and by Monday most locations will be dry. This drying will
come to an abrupt end by Tuesday and into the middle of next week
as a very cool and wet upper level low parks over the Inland
Northwest. Moderate to locally heavy precipitation will be
possible especially over northeast Washington and the northern
Panhandle.
&&
.DISCUSSION...
Tonight and Saturday: The Inland NW remains under a broad
upper-level trof that extends from the Gulf of AK to the
southwestern US. Afternoon heating has destabilized the air mass
and resulted in widely scattered showers which are rotating
cyclonically across the region. Given the lack of wind shear,
these storms are pulsing or going up quickly...then collapsing
just as quick but isolated lightning strikes have been observed
over multiple locations such as Colville...Nespelem...Methow
Valley...and Mission Ridge. The main threats with most activity
will be brief downpours...cloud to ground lightning strikes... and
pea size hail. A majority of this activity will dissipate with
sunset but there are some exceptions. Water vapor imagery in
conjunction with short-term model data clearly shows a shortwave
trof axis extending from the Puget Sound S/SE to the Tri-Cities.
As this boundary lifts N/NE overnight...we anticipate elevated
showers to continue through the night across portions of Ern WA
and Nrn ID...generally north and east of a line from Grand Coulee
to Pomeroy and some locations that miss out on surface based
convection this afternoon over Nrn ID and far NE WA may get a
renewed chance with the nocturnal activity.
Generally a repeat for Saturday`s weather with diurnally driven
showers and isolated thunder forming over the higher terrain
early then expanding into the Basin through the late afternoon.
Slightly better mixing and some drying behind this evening`s trof
passage should lower the threat for the southwestern Basin but
with a secondary shortwave trof already closing in on 130W and
expected to drop in northern Oregon Saturday afternoon...not so
sure these locations will experience a completely dry day.
Temperatures will remain near to slightly below seasonal
readings...highly dependent on whether a rain shower impacts the
location or not. /sb
Saturday evening through Tuesday evening...The model solutions are
in very good agreement that the next in a series of upper level
troughs will move into the region beginning late Saturday and
drifting slowly east/southeast toward central Idaho on Sunday.
Although this system will weaken steadily as it drifts through the
region...it will have a slight negative tilt as well. This
negative tilt is usually a good sign that the area will be subject
to convection deep enough to support thunderstorms and this will
likely be no exception. However with the base of the trough
expected to dig steadily south of the forecast area...much of the
upper level divergence and lift will remain out of the area as
well. Looks like most of the precipitation threat will occur over
the eastern half of the forecast area and will likely persist into
Sunday evening. By Monday...the area will begin to see shortwave
ridging accompanied by an intrusion of much drier air in the lower
and middle atmosphere. This should bring dry weather to most if
not all locations with the only exception occurring over the
extreme eastern Panhandle.
The brief lull in the precipitation will come to an end sometime on
Tuesday as a very deep upper level low has its sights set on much
of the Pacific Northwest. By Tuesday afternoon...there is good
model agreement that the center of a 540dm 500 mb low will be
parked just off the Washington coast. This places much of our
forecast area under deep southerly flow and an increasing threat
of precipitation. Precipitable water values will rapidly climb
toward .75 inches which is roughly 150 percent of the seasonal
normal. As the moisture moves in we expect to see a well-defined
band of precipitation develop ahead of a slow-moving cold front.
While precipitation from the front may have a tough time amounting
to much in the lee of the Cascades...it will likely intensify as
it tracks into the eastern half of the Columbia Basin on its way
toward the Idaho Panhandle. The big question is how quickly will
the front track into the Panhandle. The slower it moves...the
better chance there will be for deep convection firing ahead of
the front...while the faster would likely inhibit the chances. GFS
CAPE forecasts place values around 1000-1500 j/kg with very little
CIN which would support a chance of strong thunderstorms. We will
wait and see if there is some consistency between model runs
before jumping into this solution. While the threat of strong
thunderstorms remains questionable...there is a much better chance
of seeing moderate precipitation especially near the Canadian
border. fx
Tuesday night through Friday...wet and unseasonably cool conditions
will be the main story for the extended forecast period. Medium
range models are in good agreement on an upper level low settling
over the region with widespread precipitation across the Inland
Northwest for Tuesday night and Wednesday. There is some spread in
the evolution of the low regarding the splitting of the energy and
where the vorticity lobes will track by Friday. With increasing
confidence in the mid-week forecast, PoPs have been increased and
daytime temperatures have been lowered, especially for Wednesday
when the upper low will be overhead. Fortunately for flooding
concerns, snow levels will be lower, keeping much of the higher
elevation precip as snow rather than rain/runoff. Precip at mid and
lower elevations will still be adding to runoff into streams and
rivers that are already running high. /Kelch
&&
.AVIATION...
18Z TAFS: Modest cold pool aloft coupled with aftn heating and a
few weak midlevel circulations will promote widely scattered showers
across the region with every terminal having a small chance for
-shra. Isold -tsra will be possible but the threat is too low to
include in TAF forecast. Surface based convection will dissipate
aft 02z but a weak midlevel wave lifting through the region will
bring the potential for nocturnal showers mainly east of Moses Lake
through the overnight period. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 65 45 66 45 69 / 70 40 20 20 10 10
Coeur d`Alene 46 64 44 64 44 68 / 60 40 30 30 20 10
Pullman 47 63 43 63 42 68 / 40 20 20 20 10 0
Lewiston 51 70 49 70 48 75 / 40 20 20 20 10 0
Colville 47 70 44 73 43 75 / 50 50 40 30 20 10
Sandpoint 46 64 43 64 42 68 / 50 40 40 40 30 10
Kellogg 46 60 44 59 45 66 / 60 40 30 40 40 10
Moses Lake 50 73 47 76 46 77 / 30 10 10 10 0 0
Wenatchee 50 68 48 72 48 75 / 40 10 10 10 0 0
Omak 48 71 43 74 42 75 / 50 40 20 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 171741
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
943 AM PDT Fri May 17 2013
.SYNOPSIS...
There will be little change to the current spring progressive
weather pattern through Monday. Expect seasonable temperatures
and occasional weak disturbances bearing scattered showers and a
few thunderstorms. Tuesday and through the remainder of next week
expect a very cool and wet weather pattern.
&&
.DISCUSSION...
Morning update: Much of Ern Wa and Nrn ID is dry and sunny at this
time with several weak midlevel disturbances knocking on our
doorstep. The first is a shortwave trof which extends from the
Seattle Area southeast toward NE Oregon. This feature will slowly
lift N/NE through the day and enhance showers across the Cascades
and western sections of the Columbia Basin. A second wave will
clip the Camas Prairie and Central Panhandle Mtns. In between,
surface heating will provide a few hundred joules of SB Cape and
lead to widely scattered showers. These showers will initiate off
the higher terrain between now and noon then begin to blossom over
the lowlands as well and just about every location will have the
potential for a shower or two this afternoon. Temperatures will be
a few degrees warmer then Thursday across portions of NE WA and
Nrn ID...trending similar across the central CWA...then cooler
toward locations like Wenatchee and Moses Lake where cloud cover
will be more prevalent. /sb
&&
.AVIATION...
18Z TAFS: Modest cold pool aloft coupled with aftn heating and a
few weak midlevel circulations will promote widely scattered showers
across the region with every terminal having a small chance for
-shra. Isold -tsra will be possible but the threat is too low to
include in TAF forecast. Surface based convection will dissipate
aft 02z but a weak midlevel wave lifting through the region will
bring the potential for nocturnal showers mainly east of Moses Lake
through the overnight period. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 69 48 65 45 65 46 / 20 20 40 10 10 10
Coeur d`Alene 66 47 64 44 64 45 / 30 20 40 10 20 10
Pullman 64 47 63 42 62 43 / 30 20 20 10 10 10
Lewiston 71 52 70 48 69 49 / 20 20 20 10 10 10
Colville 74 47 70 45 72 43 / 30 30 50 50 20 10
Sandpoint 67 46 65 43 64 43 / 40 30 40 30 30 10
Kellogg 62 48 61 44 59 46 / 40 30 40 20 30 20
Moses Lake 74 51 72 48 75 46 / 20 20 10 10 10 0
Wenatchee 71 52 67 49 71 49 / 20 30 10 10 10 0
Omak 75 47 71 44 73 42 / 20 30 40 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 171643
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
943 AM PDT Fri May 17 2013
.SYNOPSIS...
There will be little change to the current spring progressive
weather pattern through Monday. Expect seasonable temperatures
and occasional weak disturbances bearing scattered showers and a
few thunderstorms. Tuesday and through the remainder of next week
expect a very cool and wet weather pattern.
&&
.DISCUSSION...
Morning update: Much of Ern Wa and Nrn ID is dry and sunny at this
time with several weak midlevel disturbances knocking on our
doorstep. The first is a shortwave trof which extends from the
Seattle Area southeast toward NE Oregon. This feature will slowly
lift N/NE through the day and enhance showers across the Cascades
and western sections of the Columbia Basin. A second wave will
clip the Camas Prairie and Central Panhandle Mtns. In between,
surface heating will provide a few hundred joules of SB Cape and
lead to widely scattered showers. These showers will initiate off
the higher terrain between now and noon then begin to blossom over
the lowlands as well and just about every location will have the
potential for a shower or two this afternoon. Temperatures will be
a few degrees warmer then Thursday across portions of NE WA and
Nrn ID...trending similar across the central CWA...then cooler
toward locations like Wenatchee and Moses Lake where cloud cover
will be more prevalent. /sb
&&
.AVIATION...
12Z TAFS: General low pressure along with marginal instability
and very small disturbances passing over and near the area
allow for the prolonged mention of showers and possibly a
thunderstorm or two in various shape and form. Additionally
some late night and early morning valley fog in northern
valleys may bring visibilities down to MVFR..but other than
that overall VFR conditions are expected to prevail through 12Z
Saturday. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 69 48 65 45 65 46 / 20 20 40 10 10 10
Coeur d`Alene 66 47 64 44 64 45 / 30 20 40 10 20 10
Pullman 64 47 63 42 62 43 / 30 20 20 10 10 10
Lewiston 71 52 70 48 69 49 / 20 20 20 10 10 10
Colville 74 47 70 45 72 43 / 30 30 50 50 20 10
Sandpoint 67 46 65 43 64 43 / 40 30 40 30 30 10
Kellogg 62 48 61 44 59 46 / 40 30 40 20 30 20
Moses Lake 74 51 72 48 75 46 / 20 20 10 10 10 0
Wenatchee 71 52 67 49 71 49 / 20 30 10 10 10 0
Omak 75 47 71 44 73 42 / 20 30 40 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 171128
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
425 AM PDT Fri May 17 2013
.SYNOPSIS...
There will be little change to the current spring progressive
weather pattern through Monday. Expect seasonable temperatures
and occasional weak disturbances bearing scattered showers and a
few thunderstorms. Tuesday and through the remainder of next week
expect a very cool and wet weather pattern.
&&
.DISCUSSION...
Today through Saturday...Subtle changes to the general tr of
pattern as the large scale tr of axis migrates eastward and into
Saturday but even with this change the air-mass continues to
remain cool and somewhat unstable. Models continue to suggest a
mixture of both surface based convection during the afternoon and
evening hours along with elevated forced convection during the
overnight hours produced by small shortwaves of mescal and
smaller passing through remain a valid description of the shower
and slight chance of thunderstorm potential that remains in some
shape or form through this time interval. Since the surface based
convection is a bit easier in some respect to anchor down over
primarily orographically favored areas the afternoon and evening
pops remain the highest and tied to the higher mountains.
Shortwave kickers such as the disturbance passing through Oregon
this morning will add complexity to the scenario by not only being
the primary forcing mechanism for nighttime elevated convection
but potentially remaining and cluttering up the surface based
convection in the afternoon and evenings. Weak cold front passage
during the day Saturday allows for a cooling trend in temperatures
and perhaps an increase in wind. /Platte
Saturday night through Tuesday night...The models are starting to
come together on just what the weather pattern for the Pacific
Northwest will be through the medium time frame of the forecast.
The pattern will change from a progressive pattern with hit or
miss showers and a few embedded thunderstorms to a deep low
pressure system dropping into the region Monday night and Tuesday
and lingering through the remainder of the week.
Saturday night through Monday the upper level trough will split
and exit the region on Sunday and allow weak high pressure to
build into the region. There will still be some afternoon surface
based convection for mountain showers...but the Pacific moisture
tap gets cut-off and that should result in a drying trend. More
sun and warming 85MB temperatures will also result in short
warming trend both Sunday and Monday.
The models have come together to indicate that a deep upper level
low will drop down out of the Gulf of Alaska Monday night and take
up position just off the Washington coast early Tuesday. Plenty of
moisture will get advocated north in the resultant southerly flow
Monday night and early Tuesday. Warm frontal lift is very weak and
any precipitation that will get squeezed out will most likely fall
as VIRGA with a very dry sub-cloud layer. The best chance for
precipitation will be tied with the better dynamics and forcing
associated with the cold front as it moves east of the Cascades
Tuesday afternoon. WATS increase to over a 100 percent of
normal...so there will be plenty of moisture to work with and
except for the lower east slopes and deep basin most locations
will see rain. Max temperatures on Tuesday will be tricky and
dependent on the timing of the cold front but are expected to
cool 5-10 degrees. /Tobin
Tuesday Night through Thursday Night: This period will see the
continuation of the unsettled weather pattern that has been
present in the region for a while now. The system that moved in from
the Gulf of Alaska will remain in place staying over western or
central Washington through the period depending on model of choice.
The best chance for widespread rain will come as the cold front
pushes through Tuesday afternoon into Wednesday as it pushes from
west to northeast centered around the upper level low. The front
will bring cooler temps that will dip below seasonal averages
along with cloudy skies.
Starting at the beginning of the period...models (EMF/GS/GEM)
came into pretty good agreement with the latest run showing the
synoptic set up and rain band associated with the front Tuesday
afternoon and into Wednesday. With the placement of the system
being very close to the WA coastline it will be able to pump in an
abundance of moisture allowing the front to be pretty moist. The
only differences in the models would be slight timing issues which
is common this far out. The GS would be the fastest of the
solutions...but the EMF would only trail by 6 hrs and made up
significant ground on the GS/GEM with the last model run.
Wednesday morning the GEM then deviates from the other two pushing
the center of the low to the north into BC. As we further
approach the event I anticipate better model agreement amongst
models.
Following the main front...post frontal moisture will remain in
place allowing for continued showers that will be most common in
the higher elevations of NE Washington along with the Cascade
Crests and the ID Panhandle. This threat of rain for mainly the
higher elevations will persist through the period with the low
remaining stationary over western/central Washington.
Rainfall amounts this far out are tough to pin down with the model
differences...but with the amount of moisture that will funnel in
with the system we can expect to see rises in the local streams
and rivers. With some already running high this could cause some
flooding concerns. Some changes that were made that could help
with this was the lowering of snow levels a little bit. With lower
snow levels the higher elevations would see likely snow and this
would allow for water storage rather than runoff as would come if
the PF fell as rain. This will play an important part as to the
amount of rise we will see in the rivers and streams. With the
current scenario we would see less runoff due to high elevation
snow...but changes in models could lead to necessary forecast updates
so this event will have to be monitored closely as we approach it.
/Lehman
&&
.AVIATION...
12Z TAFS: General low pressure along with marginal instability
and very small disturbances passing over and near the area
allow for the prolonged mention of showers and possibly a
thunderstorm or two in various shape and form. Additionally
some late night and early morning valley fog in northern
valleys may bring visibilities down to MVFR..but other than
that overall VFR conditions are expected to prevail through 12Z
Saturday. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 69 48 65 45 65 46 / 20 20 40 10 10 10
Coeur d`Alene 68 47 64 44 64 45 / 30 20 40 10 20 10
Pullman 67 47 63 42 62 43 / 30 20 20 10 10 10
Lewiston 73 52 70 48 69 49 / 20 20 20 10 10 10
Colville 74 47 70 45 72 43 / 30 30 50 50 20 10
Sandpoint 68 46 65 43 64 43 / 40 30 40 30 30 10
Kellogg 65 48 61 44 59 46 / 40 30 40 20 30 20
Moses Lake 78 51 72 48 75 46 / 10 10 10 10 10 0
Wenatchee 74 52 67 49 71 49 / 20 10 10 10 10 0
Omak 74 47 71 44 73 42 / 20 20 40 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 170931
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
231 AM PDT Fri May 17 2013
.SYNOPSIS...
There will be little change to the current spring progressive
weather pattern through Monday. Expect seasonable temperatures
and occasional weak disturbances bearing scattered showers and a
few thunderstorms. Tuesday and through the remainder of next week
expect a very cool and wet weather pattern.
&&
.DISCUSSION...
Today through Saturday...Subtle changes to the general tr of
pattern as the large scale tr of axis migrates eastward and into
Saturday but even with this change the air-mass continues to
remain cool and somewhat unstable. Models continue to suggest a
mixture of both surface based convection during the afternoon and
evening hours along with elevated forced convection during the
overnight hours produced by small shortwaves of mescal and
smaller passing through remain a valid description of the shower
and slight chance of thunderstorm potential that remains in some
shape or form through this time interval. Since the surface based
convection is a bit easier in some respect to anchor down over
primarily orographically favored areas the afternoon and evening
pops remain the highest and tied to the higher mountains.
Shortwave kickers such as the disturbance passing through Oregon
this morning will add complexity to the scenario by not only being
the primary forcing mechanism for nighttime elevated convection
but potentially remaining and cluttering up the surface based
convection in the afternoon and evenings. Weak cold front passage
during the day Saturday allows for a cooling trend in temperatures
and perhaps an increase in wind. /Platte
Saturday night through Tuesday night...The models are starting to
come together on just what the weather pattern for the Pacific
Northwest will be through the medium time frame of the forecast.
The pattern will change from a progressive pattern with hit or
miss showers and a few embedded thunderstorms to a deep low
pressure system dropping into the region Monday night and Tuesday
and lingering through the remainder of the week.
Saturday night through Monday the upper level trough will split
and exit the region on Sunday and allow weak high pressure to
build into the region. There will still be some afternoon surface
based convection for mountain showers...but the Pacific moisture
tap gets cut-off and that should result in a drying trend. More
sun and warming 85MB temperatures will also result in short
warming trend both Sunday and Monday.
The models have come together to indicate that a deep upper level
low will drop down out of the Gulf of Alaska Monday night and take
up position just off the Washington coast early Tuesday. Plenty of
moisture will get advocated north in the resultant southerly flow
Monday night and early Tuesday. Warm frontal lift is very weak and
any precipitation that will get squeezed out will most likely fall
as VIRGA with a very dry sub-cloud layer. The best chance for
precipitation will be tied with the better dynamics and forcing
associated with the cold front as it moves east of the Cascades
Tuesday afternoon. WATS increase to over a 100 percent of
normal...so there will be plenty of moisture to work with and
except for the lower east slopes and deep basin most locations
will see rain. Max temperatures on Tuesday will be tricky and
dependent on the timing of the cold front but are expected to
cool 5-10 degrees. /Tobin
Tuesday Night through Thursday Night: This period will see the
continuation of the unsettled weather pattern that has been
present in the region for a while now. The system that moved in from
the Gulf of Alaska will remain in place staying over western or
central Washington through the period depending on model of choice.
The best chance for widespread rain will come as the cold front
pushes through Tuesday afternoon into Wednesday as it pushes from
west to northeast centered around the upper level low. The front
will bring cooler temps that will dip below seasonal averages
along with cloudy skies.
Starting at the beginning of the period...models (EMF/GS/GEM)
came into pretty good agreement with the latest run showing the
synoptic set up and rain band associated with the front Tuesday
afternoon and into Wednesday. With the placement of the system
being very close to the WA coastline it will be able to pump in an
abundance of moisture allowing the front to be pretty moist. The
only differences in the models would be slight timing issues which
is common this far out. The GS would be the fastest of the
solutions...but the EMF would only trail by 6 hrs and made up
significant ground on the GS/GEM with the last model run.
Wednesday morning the GEM then deviates from the other two pushing
the center of the low to the north into BC. As we further
approach the event I anticipate better model agreement amongst
models.
Following the main front...post frontal moisture will remain in
place allowing for continued showers that will be most common in
the higher elevations of NE Washington along with the Cascade
Crests and the ID Panhandle. This threat of rain for mainly the
higher elevations will persist through the period with the low
remaining stationary over western/central Washington.
Rainfall amounts this far out are tough to pin down with the model
differences...but with the amount of moisture that will funnel in
with the system we can expect to see rises in the local streams
and rivers. With some already running high this could cause some
flooding concerns. Some changes that were made that could help
with this was the lowering of snow levels a little bit. With lower
snow levels the higher elevations would see likely snow and this
would allow for water storage rather than runoff as would come if
the PF fell as rain. This will play an important part as to the
amount of rise we will see in the rivers and streams. With the
current scenario we would see less runoff due to high elevation
snow...but changes in models could lead to necessary forecast updates
so this event will have to be monitored closely as we approach it.
/Lehman
&&
.AVIATION...
06Z TAFS: Mid to high level clouds will stream in over the region
tonight as another weak shortwave trough of low pressure pushes in
closer to the region from the southwest. Light rain showers will
continue through the night north and west of KMWH and KEAT. Patchy
fog is expected to develop across the mountain valleys north of
the Spokane/Coeur d`Alene area. This fog may develop right along
the Spokane River around sunrise, which may impact KSFF for an
hour or two with reduced vis possible. Showers will become more
widespread by tomorrow afternoon, especially over the higher
terrain. There is a small chance for a thunderstorm in the in the
vicinity of the Spokane and Coeur d`Alene taf sites tomorrow
afternoon, but confidence is low at this time. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 69 48 65 45 65 46 / 20 20 40 10 10 10
Coeur d`Alene 68 47 64 44 64 45 / 30 20 40 10 20 10
Pullman 67 47 63 42 62 43 / 30 20 20 10 10 10
Lewiston 73 52 70 48 69 49 / 20 20 20 10 10 10
Colville 74 47 70 45 72 43 / 30 30 50 50 20 10
Sandpoint 68 46 65 43 64 43 / 40 30 40 30 30 10
Kellogg 65 48 61 44 59 46 / 40 30 40 20 30 20
Moses Lake 78 51 72 48 75 46 / 10 10 10 10 10 0
Wenatchee 74 52 67 49 71 49 / 20 10 10 10 10 0
Omak 74 47 71 44 73 42 / 20 20 40 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 170555
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1055 PM PDT Thu May 16 2013
.SYNOPSIS...
A spring time progressive weather pattern will continue through
the weekend featuring seasonably mild conditions and occasional
weak storm systems bearing scattered showers and a few
thunderstorms. The next week will begin manly dry and mild...but
there is increasing confidence that a wet and cool period will
envelop the region by mid-week.
&&
.DISCUSSION...
A quick update to bump up POPs a bit across the Waterville Plateau
to the Okanogan Valley and over into the East Slopes of the
Northern Cascades. Isolated to scattered showers continue to
develop across this area late this evening as a shortwave moving
onshore interacts with some upper level instability. Expect this
activity to continue through Friday morning. Showers will then
become more widespread late tomorrow morning into the afternoon as
the atmosphere destabilizes with daytime heating. /SVH
&&
.AVIATION...
06Z TAFS: Mid to high level clouds will stream in over the region
tonight as another weak shortwave trough of low pressure pushes in
closer to the region from the southwest. Light rain showers will
continue through the night north and west of KMWH and KEAT. Patchy
fog is expected to develop across the mountain valleys north of
the Spokane/Coeur d`Alene area. This fog may develop right along
the Spokane River around sunrise, which may impact KSFF for an
hour or two with reduced vis possible. Showers will become more
widespread by tomorrow afternoon, especially over the higher
terrain. There is a small chance for a thunderstorm in the in the
vicinity of the Spokane and Coeur d`Alene taf sites tomorrow
afternoon, but confidence is low at this time. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 48 69 48 65 44 65 / 0 20 20 40 10 10
Coeur d`Alene 44 68 47 64 43 63 / 0 30 20 40 10 20
Pullman 46 67 47 63 41 62 / 0 30 20 20 10 10
Lewiston 52 73 52 70 48 68 / 0 20 20 20 10 10
Colville 42 74 47 70 44 72 / 0 30 30 50 50 20
Sandpoint 41 68 46 65 43 63 / 0 40 30 40 30 30
Kellogg 46 65 48 61 44 58 / 0 40 30 40 20 30
Moses Lake 49 78 51 72 47 75 / 10 10 10 10 10 10
Wenatchee 51 74 52 67 48 70 / 30 20 10 10 10 10
Omak 45 74 47 71 43 72 / 30 20 20 40 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 170053
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
553 PM PDT Thu May 16 2013
.SYNOPSIS...
A spring time progressive weather pattern will continue through
the weekend featuring seasonably mild conditions and occasional
weak storm systems bearing scattered showers and a few
thunderstorms. The next week will begin manly dry and mild...but
there is increasing confidence that a wet and cool period will
envelop the region by mid-week.
&&
.DISCUSSION...
Forecast updated to trim down POPs over the southeastern portion
of the forecast area and expand isolated rain showers a bit
further south from the northern mountains into the northern
portions of the Upper Columbia Basin, Waterville Plateau and into
the northern portions of the Moses Lake Area. Best instability
with slightly cooler 500 mb temps of -20 to -22 C are northwest of
a line from Moses Lake to Sandpoint. This is the part of the
region that is seeing the best shower activity and colder cloud
top temperatures. I trimmed back our thunderstorm chances away
from the Central Panhandle Mountains this evening, but did leave a
slight chance for some thunderstorms over the higher terrain in
the Northern Panhandle westward over into the Okanogan Highlands
through about 800 PM this evening. Cloud top temps are getting
down to below -20 C, which is the bottom range for getting any
kind of charge separation for lightning. If we do see any
lightning this evening, it will likely only be a strike or two.
Chances of showers will diminish rapidly after sunset as these
showers are being fed from heating early this afternoon. /SVH
&&
.AVIATION...
00Z TAFS: A moist and weakly unstable air mass will reside over
the region through the TAF period. There is little in the way of
upper level dynamic support...thus clouds and showers will be
mainly driven by orographic influences and daytime heating. this
evening scattered mainly mountain showers will dissipate after
02Z-03Z followed by a quiet night with clearing skies. Patchy fog
is possible from 12Z to 18Z in northern river valleys. Scattered
afternoon showers will return on Friday with a small chance of
thunderstorms mainly over mountains. A weak disturbance aloft on
Friday may allow scattered showers to form over the Columbia Basin
after 20Z...but ceilings will likely remain VFR at all TAF sites.
/MJF
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 69 48 65 44 65 / 20 20 20 40 20 20
Coeur d`Alene 44 68 47 64 43 63 / 20 30 20 40 30 30
Pullman 44 67 47 63 41 62 / 10 30 20 20 20 10
Lewiston 50 73 52 70 48 68 / 10 20 20 20 20 20
Colville 42 74 47 70 44 72 / 30 30 30 50 50 20
Sandpoint 41 68 46 65 43 63 / 20 40 30 40 40 30
Kellogg 45 65 48 61 44 58 / 20 40 30 40 30 30
Moses Lake 48 78 51 72 47 75 / 10 10 10 10 10 10
Wenatchee 49 74 52 67 48 70 / 20 20 10 10 10 10
Omak 44 74 47 71 43 72 / 20 20 20 40 30 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 162339
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
439 PM PDT Thu May 16 2013
.SYNOPSIS...
A spring time progressive weather pattern will continue through
the weekend featuring seasonably mild conditions and occasional
weak storm systems bearing scattered showers and a few
thunderstorms. The next week will begin manly dry and mild...but
there is increasing confidence that a wet and cool period will
envelop the region by mid-week.
&&
.DISCUSSION...
Tonight through Friday...The forecast area is coming under the
influence of a deep upper level trough with it`s axis still off
the Pacific Coast this afternoon. In this pre-trough southerly
flow regime numerous relatively weak and amorphous spokes of
energy area transiting from south to north...each one capable of
exploiting a moist in-situ air mass into at least scattered
showers and an occasional stray thunderstorm. Last night featured
a more coherent wave in this flow leading to nocturnal
precipitation. Tonight models and satellite extrapolation suggest
the next coherent wave currently impacting Oregon will focus it`s
energy south of the forecast area. Thus...after afternoon diurnal
convection dies down this evening with the sunset...generally dry
and at least partially clearing conditions are expected. The moist
air mass will prevent temperatures from dropping out of the 40s at
most locations and there is a possibility of patchy morning fog in
low spots and river courses.
On Friday another and possibly more coherent wave will spread
across the region as the northern portion of the incoming trough
brushes by the forecast area. Model soundings indicate a couple
hundred joules/Kg of SB CAPE possible when morning and early
afternoon sunshine allows temperatures to approach 70 degrees
across much of the lower elevations. Thus on Friday expect a
somewhat broader threat of afternoon showers encompassing not only
the normal orographic influenced zones...but also out into the
basin...with a slightly better but still rather small chance of
thunderstorms. /Fugazzi
Friday night through Monday morning: A longwave trof will
continue to influence the weather over the Inland NW. The cool
temperatures aloft coupled with seasonal warming at the surface
will promote diurnally driven hit or miss showers each afternoon
with the northern and eastern mountains carrying the highest
threat for pcpn. Isolated thunderstorms will be possible but we
are not anticipated any strong to severe activity and only minimal
chances exist along the immediate Canadian Border. There will be a
few weak shortwaves swinging within the trof which will enhance
the precipitation threat at times...very similar to what occurred
Wednesday night/Thursday morning. Each will be capable of upwards
of a tenth of rainfall. The strongest of these waves arrives
during the day Saturday and we have expanded the threat for
showers into the Basin. Attm...we kept Wenatchee and Moses Lake
dry due to increasing northwesterly flow and moisture progs were
not overly impressive but this could be overly optimistic if the
wave is stronger then modeled. A broad upper-level low approaches
the region late Sunday into Monday morning from the north.
Shortwave ridging briefly ahead of this wave will bring some
midlevel warming and increasing stability so we adjusted PoPs
downward...especially near the Cascades and Columbia Basin. As for
temperatures, highs will be running near to slightly below
seasonal normals or 60`s and lower 70s`. Lows will be in the 40`s
to upper 30`s. /sb
Monday through Thursday...Cool and wet weather will prevail across
the Inland Northwest as an upper level low settles over the region.
Models are in general agreement with the synoptic pattern, but there
are some subtle differences in the exact track of the low pressure
center. This difference in track could lead to significant differences
in the amount of rain that falls and which areas receive the
heaviest amounts. While the last few runs of the GFS are rather
consistent, the 12Z run of the ECMWF has the system coming in a bit
slower now, which will cut down on the accumulated qpf. Even with
these differences, confidence is high that we will see an extended
period of cool and wet weather during the mid-week period. It just
remains to be seen as to just how wet it will be. Temperatures have
been trended cooler, especially on Wednesday when all models have
the upper low pretty much overhead. Snow levels have also been
lowered, to about 4500 ft by Wednesday. This will keep some of the
precip tied up as snow in the higher mountains. Area streams and
rivers will be on the rise again, with bankfull conditions possible
again by midweek. /Kelch
&&
.AVIATION...
00Z TAFS: A moist and weakly unstable air mass will reside over
the region through the TAF period. There is little in the way of
upper level dynamic support...thus clouds and showers will be
mainly driven by orographic influences and daytime heating. this
evening scattered mainly mountain showers will dissipate after
02Z-03Z followed by a quiet night with clearing skies. Patchy fog
is possible from 12Z to 18Z in northern river valleys. Scattered
afternoon showers will return on Friday with a small chance of
thunderstorms mainly over mountains. A weak disturbance aloft on
Friday may allow scattered showers to form over the Columbia Basin
after 20Z...but ceilings will likely remain VFR at all TAF sites.
/MJF
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 69 48 65 44 65 / 20 20 20 40 20 20
Coeur d`Alene 44 68 47 64 43 63 / 20 30 20 40 30 30
Pullman 44 67 47 63 41 62 / 10 30 20 20 20 10
Lewiston 50 73 52 70 48 68 / 10 20 20 20 20 20
Colville 42 74 47 70 44 72 / 30 30 30 50 50 20
Sandpoint 41 68 46 65 43 63 / 20 40 30 40 40 30
Kellogg 45 65 48 61 44 58 / 20 40 30 40 30 30
Moses Lake 48 78 51 72 47 75 / 10 10 10 10 10 10
Wenatchee 49 74 52 67 48 70 / 20 20 10 10 10 10
Omak 44 74 47 71 43 72 / 20 20 20 40 30 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 162116
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
216 PM PDT Thu May 16 2013
.SYNOPSIS...
A spring time progressive weather pattern will continue through
the weekend featuring seasonably mild conditions and occasional
weak storm systems bearing scattered showers and a few
thunderstorms. The next week will begin manly dry and mild...but
there is increasing confidence that a wet and cool period will
envelop the region by mid-week.
&&
.DISCUSSION...
Tonight through Friday...The forecast area is coming under the
influence of a deep upper level trough with it`s axis still off
the Pacific Coast this afternoon. In this pre-trough southerly
flow regime numerous relatively weak and amorphous spokes of
energy area transiting from south to north...each one capable of
exploiting a moist in-situ air mass into at least scattered
showers and an occasional stray thunderstorm. Last night featured
a more coherent wave in this flow leading to nocturnal
precipitation. Tonight models and satellite extrapolation suggest
the next coherent wave currently impacting Oregon will focus it`s
energy south of the forecast area. Thus...after afternoon diurnal
convection dies down this evening with the sunset...generally dry
and at least partially clearing conditions are expected. The moist
air mass will prevent temperatures from dropping out of the 40s at
most locations and there is a possibility of patchy morning fog in
low spots and river courses.
On Friday another and possibly more coherent wave will spread
across the region as the northern portion of the incoming trough
brushes by the forecast area. Model soundings indicate a couple
hundred joules/Kg of SB CAPE possible when morning and early
afternoon sunshine allows temperatures to approach 70 degrees
across much of the lower elevations. Thus on Friday expect a
somewhat broader threat of afternoon showers encompassing not only
the normal orographic influenced zones...but also out into the
basin...with a slightly better but still rather small chance of
thunderstorms. /Fugazzi
Friday night through Monday morning: A longwave trof will
continue to influence the weather over the Inland NW. The cool
temperatures aloft coupled with seasonal warming at the surface
will promote diurnally driven hit or miss showers each afternoon
with the northern and eastern mountains carrying the highest
threat for pcpn. Isolated thunderstorms will be possible but we
are not anticipated any strong to severe activity and only minimal
chances exist along the immediate Canadian Border. There will be a
few weak shortwaves swinging within the trof which will enhance
the precipitation threat at times...very similar to what occurred
Wednesday night/Thursday morning. Each will be capable of upwards
of a tenth of rainfall. The strongest of these waves arrives
during the day Saturday and we have expanded the threat for
showers into the Basin. Attm...we kept Wenatchee and Moses Lake
dry due to increasing northwesterly flow and moisture progs were
not overly impressive but this could be overly optimistic if the
wave is stronger then modeled. A broad upper-level low approaches
the region late Sunday into Monday morning from the north.
Shortwave ridging briefly ahead of this wave will bring some
midlevel warming and increasing stability so we adjusted PoPs
downward...especially near the Cascades and Columbia Basin. As for
temperatures, highs will be running near to slightly below
seasonal normals or 60`s and lower 70s`. Lows will be in the 40`s
to upper 30`s. /sb
Monday through Thursday...Cool and wet weather will prevail across
the Inland Northwest as an upper level low settles over the region.
Models are in general agreement with the synoptic pattern, but there
are some subtle differences in the exact track of the low pressure
center. This difference in track could lead to significant differences
in the amount of rain that falls and which areas receive the
heaviest amounts. While the last few runs of the GFS are rather
consistent, the 12Z run of the ECMWF has the system coming in a bit
slower now, which will cut down on the accumulated qpf. Even with
these differences, confidence is high that we will see an extended
period of cool and wet weather during the mid-week period. It just
remains to be seen as to just how wet it will be. Temperatures have
been trended cooler, especially on Wednesday when all models have
the upper low pretty much overhead. Snow levels have also been
lowered, to about 4500 ft by Wednesday. This will keep some of the
precip tied up as snow in the higher mountains. Area streams and
rivers will be on the rise again, with bankfull conditions possible
again by midweek. /Kelch
&&
.AVIATION...
18Z TAFS: A moist low level air mass manifesting itself with high
MVFR or low VFR stratus decks this morning will break up into
generally VFR stratocumulus after 20Z. Scattered showers will
develop mainly over the mountains with a small possibility of
thunderstorms between 20Z and 02Z. Isolated showers with VFR
ceilings are possible over the eastern TAF sites as well this
afternoon and evening. Tonight shower activity will die down after
02Z-03Z with VFR conditions. By 12Z-15Z the KLWS and KEAT TAF
sites may be impacted by thickening VFR ceilings as another weak
storm system passes by to the south of the forecast area. /MJF
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 69 48 65 44 65 / 20 20 20 40 20 20
Coeur d`Alene 44 68 47 64 43 63 / 20 30 20 40 30 30
Pullman 44 67 47 63 41 62 / 10 30 20 20 20 10
Lewiston 50 73 52 70 48 68 / 10 20 20 20 20 20
Colville 42 74 47 70 44 72 / 30 30 30 50 50 20
Sandpoint 41 68 46 65 43 63 / 20 40 30 40 40 30
Kellogg 45 65 48 61 44 58 / 20 40 30 40 30 30
Moses Lake 48 78 51 72 47 75 / 10 10 10 10 10 10
Wenatchee 49 74 52 67 48 70 / 20 20 10 10 10 10
Omak 44 74 47 71 43 72 / 20 20 20 40 30 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 161740
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1040 AM PDT Thu May 16 2013
.SYNOPSIS...
A spring time progressive weather pattern will continue through
the next week featuring seasonably cool conditions and occasional
weak storm systems bearing scattered showers and a few
thunderstorms. A stronger storm with a cooling trend is possible by
the middle of next week.
&&
.DISCUSSION...
Rest of today...An upper level trough will influence the area`s weather
through the day today...with satellite indicating what appears to
be a 7000 mb vorticity maximum circulating near Davenport this
morning while some clearing is apparent over the Canadian Border
region. To the northeast lingering showers from the overnight
precipitation band continue to linger. Last nights round of light
rain has left a very moist low level air mass across much of the
region...with model soundings indicating unstable mid level lapse
rates compliments of the cool trough aloft.
For the rest of today and into this evening sunbreaks will
probably be sufficient to generate up to 100 joules or so of SB
CAPE promoting a re-generation of scattered rain showers mainly
over the mountain zones...especially those zones where clearing is
occurring now. Over the eastern basin and the Idaho Panhandle
heavier cloud cover will hold temperatures down today...but by
afternoon the stratus layers will probably break into scattered to
broken stratocumulus and allow some sunbreaks to promote showers
as well.
Thus...for the rest of today a generally damp and cloudy morning
will turn into a partly sunny and showery afternoon. By no means a
wash-out...but most locations will be at risk for a brief sprinkle
or a few hundredths of an inch of short lived rain showers.
Thunderstorm potential is rather low...but cannot be ruled out
mainly over the mountain zones ringing the basin. High
temperatures will be difficult to nail down with any
certainty...but it is safe to say that without any appreciable air
mass change over yesterday today`s highs will probably not stray
far from yesterday`s highs in sunny areas and will achieve a few
degrees cooler than yesterday in those areas where heavy cloud
cover currently exists. /Fugazzi
&&
.AVIATION...
18Z TAFS: A moist low level air mass manifesting itself with high
MVFR or low VFR stratus decks this morning will break up into
generally VFR stratocumulus after 20Z. Scattered showers will
develop mainly over the mountains with a small possibility of
thunderstorms between 20Z and 02Z. Isolated showers with VFR
ceilings are possible over the eastern TAF sites as well this
afternoon and evening. Tonight shower activity will die down after
02Z-03Z with VFR conditions. By 12Z-15Z the KLWS and KEAT TAF
sites may be impacted by thickening VFR ceilings as another weak
storm system passes by to the south of the forecast area. /MJF
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 47 69 48 67 45 / 30 20 10 20 40 20
Coeur d`Alene 61 44 67 46 66 44 / 50 20 20 20 40 20
Pullman 64 44 66 46 63 42 / 20 10 10 20 20 10
Lewiston 72 50 74 52 71 49 / 20 10 10 20 10 10
Colville 69 42 75 46 72 44 / 60 30 20 30 50 60
Sandpoint 62 41 67 44 67 43 / 60 20 20 30 40 40
Kellogg 58 45 64 47 62 45 / 50 20 20 30 40 30
Moses Lake 76 48 77 51 74 47 / 10 10 10 10 10 10
Wenatchee 73 49 73 52 70 48 / 20 10 10 10 10 10
Omak 73 44 75 47 73 43 / 30 20 10 20 40 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 161635
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
935 AM PDT Thu May 16 2013
.SYNOPSIS...
A spring time progressive weather pattern will continue through
the next week featuring seasonably cool conditions and occasional
weak storm systems bearing scattered showers and a few
thunderstorms. A stronger storm with a cooling trend is possible by
the middle of next week.
&&
.DISCUSSION...
Rest of today...An upper level trough will influence the area`s weather
through the day today...with satellite indicating what appears to
be a 7000 mb vorticity maximum circulating near Davenport this
morning while some clearing is apparent over the Canadian Border
region. To the northeast lingering showers from the overnight
precipitation band continue to linger. Last nights round of light
rain has left a very moist low level air mass across much of the
region...with model soundings indicating unstable mid level lapse
rates compliments of the cool trough aloft.
For the rest of today and into this evening sunbreaks will
probably be sufficient to generate up to 100 joules or so of SB
CAPE promoting a re-generation of scattered rain showers mainly
over the mountain zones...especially those zones where clearing is
occurring now. Over the eastern basin and the Idaho Panhandle
heavier cloud cover will hold temperatures down today...but by
afternoon the stratus layers will probably break into scattered to
broken stratocumulus and allow some sunbreaks to promote showers
as well.
Thus...for the rest of today a generally damp and cloudy morning
will turn into a partly sunny and showery afternoon. By no means a
wash-out...but most locations will be at risk for a brief sprinkle
or a few hundredths of an inch of short lived rain showers.
Thunderstorm potential is rather low...but cannot be ruled out
mainly over the mountain zones ringing the basin. High
temperatures will be difficult to nail down with any
certainty...but it is safe to say that without any appreciable air
mass change over yesterday today`s highs will probably not stray
far from yesterday`s highs in sunny areas and will achieve a few
degrees cooler than yesterday in those areas where heavy cloud
cover currently exists. /Fugazzi
&&
.AVIATION...
12Z TAFS: A weak weather system passing this morning is bringing
rain to mostly locations north of the TAF sites. Ceilings
associated with precipitation are not expected to get much lower
than this level with VFR conditions expected through Thursday
evening. The atmosphere will destabilize this afternoon with
isolated thunderstorms possible over the mountains. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 63 47 69 48 67 45 / 30 20 10 20 40 20
Coeur d`Alene 61 44 67 46 66 44 / 50 20 20 20 40 20
Pullman 64 44 66 46 63 42 / 20 10 10 20 20 10
Lewiston 72 50 74 52 71 49 / 20 10 10 20 10 10
Colville 69 42 75 46 72 44 / 60 30 20 30 50 60
Sandpoint 62 41 67 44 67 43 / 60 20 20 30 40 40
Kellogg 58 45 64 47 62 45 / 50 20 20 30 40 30
Moses Lake 76 48 77 51 74 47 / 10 10 10 10 10 10
Wenatchee 73 49 73 52 70 48 / 20 10 10 10 10 10
Omak 73 44 75 47 73 43 / 30 20 10 20 40 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 161126
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
426 AM PDT Thu May 16 2013
.SYNOPSIS...
A spring time progressive weather pattern will continue through
the next week featuring seasonably cool conditions and occasional
weak storm systems bearing scattered showers and a few
thunderstorms. A stronger storm with a cooling trend is possible by
the middle of next week.
&&
.DISCUSSION...
Today through Friday...General low pressure cluttered with
small scale disturbances rotating around in and through it along
with some marginal instability allow for prolonged mention of pops
for showers through this time interval...both surface based and
elevated (nighttime) convection. Subtle change is that the flow of
disturbances coming in becomes a bit more from the south on Friday
therefore forecast temps show a slight warming trend into Friday
but nothing straying too far from what would be considered normal
for this time of year (which seems quite cool now since the past
workweek before Mothers Day weekend was so unseasonably warm with
temps in the 80s and 90s). Minor mention of afternoon/early
evening thunder remains confined primarily to mountains. /Pelatti
Friday night through Monday night...Interesting turn of events
with guidance through the weekend. The models were showing an
upper level low moving through B.C and dragging a front through
the forecast area on Saturday...then closing off in western
Montana on Sunday. But over the last couple of model runs there
were hints at the possibility of the trough splitting as it moved
inland and then closing off much further south and east...and this
seems to be the way the models are playing it this morning. There
will still be a chance of showers and localized mainly terrain
driven thunderstorms...but precipitation should be quite a bit
less than previous thinking. Then a much deeper upper level low
that is currently in the Bering sea is expected to drop south
along the B.C coast on Monday and take up position over northwest
Washington by Tuesday. The models are showing similar solutions
but there are some timing differences.
Friday night into Saturday the incoming trough will hold together
long enough into Saturday morning for increasing Pacific
moisture. In addition enough of a short wave disturbance will
create the lift required to tap into afternoon surface instability
for mountain showers and the low end chance of a thunderstorm or
two. Some places in the northeast mountains could see around a
tenth of an inch through Saturday evening...otherwise a few
hundredths here and there. The flow becomes west-northwest on
Sunday as the trough exits the region. With little more than
orographic support to work with showers should be focused over the
northeast mountains and the Idaho panhandle mountains from mid
afternoon into evening. Temperatures will be very near seasonal
norms.
Things get a bit more complicated on Monday and into the future.
As mentioned above the solutions are similar...but the timing is
off. For this forecast we leaned towards the slightly slower
ECMWF. Weak high pressure will build ahead of the incoming storm
system. The flow will turn southwest and will result in showers
aimed at the northeast portion of my forecast area...otherwise a
dry forecast with temperatures a little warmer than through the
weekend. /Tobin
Tuesday through Thursday night... Feature of interest continues to
be the slow moving low pressure that will set up shop over the
Inland/Pacific Northwest. After its ride down the BC coast early
next week the circulation stalls. It`s the evolution from this
point that is under some debate. There is still some question on
where it ends up, right over top of us or to the east/west. We
have a few days to watch it so will not make many changes to the
forecast. Temperatures were cooled a degree or two in some cases,
and many areas are likely to see early morning freezing
temperatures (at least briefly). Precipitation chances were kept
in the slight/chance category until we can get a bitter idea on
movement of the system. ty
&&
.AVIATION...
12Z TAFS: A weak weather system passing this morning is bringing
rain to mostly loctions north of the TAF sites. Ceilings
associated with precipitation are not expected to get much lower
than this level with VFR conditions expected through Thursday
evening. The atmosphere will destabilize this afternoon with
isolated thunderstorms possible over the mountains. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 65 47 69 48 67 45 / 40 20 10 20 40 20
Coeur d`Alene 63 44 67 46 66 44 / 50 20 20 20 40 20
Pullman 64 44 66 46 63 42 / 30 10 10 20 20 10
Lewiston 72 50 74 52 71 49 / 30 10 10 20 10 10
Colville 70 42 75 46 72 44 / 50 30 20 30 50 60
Sandpoint 63 41 67 44 67 43 / 50 20 20 30 40 40
Kellogg 60 45 64 47 62 45 / 50 20 20 30 40 30
Moses Lake 74 48 77 51 74 47 / 20 10 10 10 10 10
Wenatchee 72 49 73 52 70 48 / 20 10 10 10 10 10
Omak 72 44 75 47 73 43 / 40 20 10 20 40 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 160910
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
210 AM PDT Thu May 16 2013
.SYNOPSIS...
A spring time progressive weather pattern will continue through
the next week featuring seasonably cool conditions and occasional
weak storm systems bearing scattered showers and a few
thunderstorms. A stronger storm with a cooling trend is possible by
the middle of next week.
&&
.DISCUSSION...
Today through Friday...General low pressure cluttered with
small scale disturbances rotating around in and through it along
with some marginal instability allow for prolonged mention of pops
for showers through this time interval...both surface based and
elevated (nighttime) convection. Subtle change is that the flow of
disturbances coming in becomes a bit more from the south on Friday
therefore forecast temps show a slight warming trend into Friday
but nothing straying too far from what would be considered normal
for this time of year (which seems quite cool now since the past
workweek before Mothers Day weekend was so unseasonably warm with
temps in the 80s and 90s). Minor mention of afternoon/early
evening thunder remains confined primarily to mountains. /Pelatti
Friday night through Monday night...Interesting turn of events
with guidance through the weekend. The models were showing an
upper level low moving through B.C and dragging a front through
the forecast area on Saturday...then closing off in western
Montana on Sunday. But over the last couple of model runs there
were hints at the possibility of the trough splitting as it moved
inland and then closing off much further south and east...and this
seems to be the way the models are playing it this morning. There
will still be a chance of showers and localized mainly terrain
driven thunderstorms...but precipitation should be quite a bit
less than previous thinking. Then a much deeper upper level low
that is currently in the Bering sea is expected to drop south
along the B.C coast on Monday and take up position over northwest
Washington by Tuesday. The models are showing similar solutions
but there are some timing differences.
Friday night into Saturday the incoming trough will hold together
long enough into Saturday morning for increasing Pacific
moisture. In addition enough of a short wave disturbance will
create the lift required to tap into afternoon surface instability
for mountain showers and the low end chance of a thunderstorm or
two. Some places in the northeast mountains could see around a
tenth of an inch through Saturday evening...otherwise a few
hundredths here and there. The flow becomes west-northwest on
Sunday as the trough exits the region. With little more than
orographic support to work with showers should be focused over the
northeast mountains and the Idaho panhandle mountains from mid
afternoon into evening. Temperatures will be very near seasonal
norms.
Things get a bit more complicated on Monday and into the future.
As mentioned above the solutions are similar...but the timing is
off. For this forecast we leaned towards the slightly slower
ECMWF. Weak high pressure will build ahead of the incoming storm
system. The flow will turn southwest and will result in showers
aimed at the northeast portion of my forecast area...otherwise a
dry forecast with temperatures a little warmer than through the
weekend. /Tobin
Tuesday through Thursday night... Feature of interest continues to
be the slow moving low pressure that will set up shop over the
Inland/Pacific Northwest. After its ride down the BC coast early
next week the circulation stalls. It`s the evolution from this
point that is under some debate. There is still some question on
where it ends up, right over top of us or to the east/west. We
have a few days to watch it so will not make many changes to the
forecast. Temperatures were cooled a degree or two in some cases,
and many areas are likely to see early morning freezing
temperatures (at least briefly). Precipitation chances were kept
in the slight/chance category until we can get a bitter idea on
movement of the system. ty
&&
.AVIATION...
06Z TAFS: A weak weather system tonight will spread thickening mid
level cloud cover across the region. Very light rain showers or
sprinkles will be possible at the taf sites with this system as cigs
decrease to around 5 kft agl. Cigs are not expected to get much
lower than this level with VFR conditions expected through Thursday
evening. The atmosphere will destabilize Thursday afternoon with
isolated thunderstorms possible over the mountains. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 65 47 69 48 67 45 / 40 20 10 20 40 20
Coeur d`Alene 63 44 67 46 66 44 / 50 20 20 20 40 20
Pullman 64 44 66 46 63 42 / 30 10 10 20 20 10
Lewiston 72 50 74 52 71 49 / 30 10 10 20 10 10
Colville 70 42 75 46 72 44 / 50 30 20 30 50 60
Sandpoint 63 41 67 44 67 43 / 50 20 20 30 40 40
Kellogg 60 45 64 47 62 45 / 50 20 20 30 40 30
Moses Lake 74 48 77 51 74 47 / 20 10 10 10 10 10
Wenatchee 72 49 73 52 70 48 / 20 10 10 10 10 10
Omak 72 44 75 47 73 43 / 40 20 10 20 40 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 160533
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1033 PM PDT Wed May 15 2013
.SYNOPSIS...
A spring time progressive weather pattern will continue through
the next week featuring seasonably cool conditions and occasional
weak storm systems bearing scattered showers and a few
thunderstorms. A stronger storm with a cooling trend is possible by
the middle of next week.
&&
.DISCUSSION...
Update: Satellite imagery as of 930 PM indicated a well defined
wave over NW Washington with a small circulation noted. Models
show this feature tracking east tonight with the bulk of the
energy tracking over locations north of the Columbia Basin
including the East Slopes of the Cascades, Okanogan Valley,
Okanogan Highlands, Northeast Washington Mountains, and the North
Idaho Panhandle. Initially there is some dry air below 800mb that
will need to moisten up. But with time...showers will be on the
increase tonight in the aforementioned areas. Elsewhere showers
will be more isolated in nature. Cloud cover will hold
temperatures up tonight around Omak, Winthrop, and Wenatchee and
lows were increased slightly.
On Thursday...a weak trough will remain over the region...which
combined with afternoon heating will trigger showers over the
region. The bulk of these will be over the mountains with no
strong forcing to initiate convection in the Columbia Basin and
adjacent valleys. Models show marginal instability for
thunderstorms...so a slight chance was maintained for the
mountains...but removed in the valleys. JW
&&
.AVIATION...
06Z TAFS: A weak weather system tonight will spread thickening mid
level cloud cover across the region. Very light rain showers or
sprinkles will be possible at the taf sites with this system as cigs
decrease to around 5 kft agl. Cigs are not expected to get much
lower than this level with VFR conditions expected through Thursday
evening. The atmosphere will destabilize Thursday afternoon with
isolated thunderstorms possible over the mountains. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 65 47 69 48 68 / 30 40 20 10 20 40
Coeur d`Alene 45 63 44 67 46 67 / 30 50 20 20 20 40
Pullman 44 64 44 66 46 64 / 20 30 10 10 20 30
Lewiston 49 72 50 74 52 72 / 10 30 10 10 20 20
Colville 45 70 42 75 46 73 / 50 50 30 20 30 50
Sandpoint 45 63 41 67 44 68 / 40 50 20 20 30 40
Kellogg 44 60 45 64 47 63 / 30 50 20 20 30 40
Moses Lake 47 74 48 77 51 75 / 10 20 10 10 10 20
Wenatchee 49 72 49 73 52 71 / 20 20 10 10 10 20
Omak 49 72 44 75 47 74 / 40 40 20 10 20 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 160441
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
941 PM PDT Wed May 15 2013
.SYNOPSIS...
A spring time progressive weather pattern will continue through
the next week featuring seasonably cool conditions and occasional
weak storm systems bearing scattered showers and a few
thunderstorms. A stronger storm with a cooling trend is possible by
the middle of next week.
&&
.DISCUSSION...
Update: Satellite imagery as of 930 PM indicated a well defined
wave over NW Washington with a small circulation noted. Models
show this feature tracking east tonight with the bulk of the
energy tracking over locations north of the Columbia Basin
including the East Slopes of the Cascades, Okanogan Valley,
Okanogan Highlands, Northeast Washington Mountains, and the North
Idaho Panhandle. Initially there is some dry air below 800mb that
will need to moisten up. But with time...showers will be on the
increase tonight in the aforementioned areas. Elsewhere showers
will be more isolated in nature. Cloud cover will hold
temperatures up tonight around Omak, Winthrop, and Wenatchee and
lows were increased slightly.
On Thursday...a weak trough will remain over the region...which
combined with afternoon heating will trigger showers over the
region. The bulk of these will be over the mountains with no
strong forcing to initiate convection in the Columbia Basin and
adjacent valleys. Models show marginal instability for
thunderstorms...so a slight chance was maintained for the
mountains...but removed in the valleys. JW
&&
.AVIATION...
00Z TAFS: A weak weather system tonight will spread thickening mid
level cloud cover across the region. Very light rain showers or
sprinkles will be possible at the taf sites with this system as cigs
decrease to around 5 kft agl. Cigs are not expected to get much
lower than this level with VFR conditions expected through Thursday
afternoon. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 65 47 69 48 68 / 30 40 20 10 20 40
Coeur d`Alene 45 63 44 67 46 67 / 30 50 20 20 20 40
Pullman 44 64 44 66 46 64 / 20 30 10 10 20 30
Lewiston 49 72 50 74 52 72 / 10 30 10 10 20 20
Colville 45 70 42 75 46 73 / 50 50 30 20 30 50
Sandpoint 45 63 41 67 44 68 / 40 50 20 20 30 40
Kellogg 44 60 45 64 47 63 / 30 50 20 20 30 40
Moses Lake 47 74 48 77 51 75 / 10 20 10 10 10 20
Wenatchee 49 72 49 73 52 71 / 20 20 10 10 10 20
Omak 49 72 44 75 47 74 / 40 40 20 10 20 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
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