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NWS Discussion
			
				

Area forecast discussion 
National Weather Service Albuquerque nm 
604 am MDT Thursday may 23 2013 


Aviation... 
12z taf cycle 
VFR conditions expected all locations east of the Central High 
terrain through period with gusty southwest winds 20 to 30kt by 
middle day persisting into early evening. Across the northeast... 
winds will shift to the north to northeast with some low clouds 
with MVFR ceilings moving into the extreme northeast this morning 
between krtn and kcao. Expect these low clouds to mix out middle 
morning around 16z or 17z. However...moisture will continue to 
increase across the eastern plains with a dry line edging into 
the state supporting thunderstorms across the east...increasing in 
coverage from afternoon into the evening hours. Northeast quadrant 
could see strong to severe thunderstorms with hail and winds in 
excess of 50kts. MVFR to possibly IFR ceilings and visibilities associated 
with the strongest storms. From 06z through 12z early Friday morning... 
low clouds and areas of fog will expand across the east. Currently 
carrying MVFR ceilings at klvs...less certain elsewhere. 


05 


&& 


Previous discussion...327 am MDT Thursday may 23 2013... 
currently...ridge over New Mexico has drifted eastward...with axis 
now lying from central Texas to the northern plains and beyond 
across the Canadian prairies and into the Canadian Arctic. Flow over 
New Mexico is shifting to the southwest in circulation about 
sprawling closed low anchoring weather system over Washington 
state and Oregon. Surface charts showing weak trough extending 
from western Kansas across eastern New Mexico to roughly El 
Paso...with dome of high pressure parked over south central 
Colorado. 


Models...in reasonable agreement through the Memorial Day weekend 
and into the first half of the following work week. Some 
differences in the details of feature placement emerging from 
Wednesday Onward...but broad story remains fairly coherent and 
with enough consensus to make some Stab at a midweek to late week 
forecast. Plausible and acceptable consensus maintains a quasi 
stationary closed low over the Pacific northwest that will 
circulate a digging shortwave onto the California coast during the 
weekend and move this first wave to The Four Corners on Memorial 
Day. Trailing shortwave a little more amplified...and this will dig 
to Baja California California early Tuesday and swing toward New Mexico by 
midweek. Domestic GFS leads European colleagues at European model (ecmwf) on trough 
passage...as GFS keeps decided negative tilt to the trough in 
phase with closed low over the eastern Gulf of Alaska while European model (ecmwf) 
maintains a less phased and more meridional trough. Bottom line 
doesnt really change for New Mexico as the midweek story is 
troughiness...and as the trough base rounds out and trough 
coverage expands over the western half of the u... 
zonal flow aloft will become established over New Mexico for the 
last half of the work week. All solutions now telegraphing dig of 
trough out of the northeast Pacific and down the California coast 
heading into the weekend...with strong zonal winds aloft backing 
to southwest over New Mexico as the weekend gets underway. 


For today...active convection on tap for the eastern plains as 
cold front drops out of the Central Plains into northeast New 
Mexico...with some chance for severe storms close to the Texas 
border. Lifted indices fall to 6 below in these areas...with 
buoyancy supported by 1000 j per kg mu cape along the Texas line. 
Mu cape locally higher over the northeast plains...and noting Storm Prediction Center 
colleagues have eastern portions of Quay...Harding...and Union 
counties under a slight risk for severe weather heading into the 
evening...as southeast winds at the surface veer with altitude to 
southwest and provide some directional shear with height. Chief 
threat appears to be large hail accompanied with some strong wind 
gusts. Otherwise...warming trend will push temperatures 6 to 12 
degrees above normal across the state with some hazy high clouds 
taking the edge off a broadly sunny day. Southwest breezes will 
develop this afternoon from the Arizona border to the Continental 
Divide...and combined with very low humidities...will produce red 
flag conditions over the northwest Highlands through this evening. 


For Friday...cold front washing out over the eastern plains...as 
surface low deepens over eastern Colorado and extends trough south 
and west across The Heart of New Mexico. Another actively 
convective day on tap for the east...with thunderstorm coverage 
expanding westward to the Central Mountain chain by Friday 
afternoon. Storms east of a Clayton to Tucumcari to Ruidoso line 
may contain some small hail and gusty winds...as lifted indices 
fall to 4 below...and mu cape remains around 1500 j per kg. Will 
need to watch this area carefully for possible need for a severe 
mention in future forecasts...but will hold with the hail and gust 
mention for now. Warming trends leveling off with temperatures 
remaining above normal for the day...with a little more cloud 
cover in the east and remaining sunny in the west. Southwest 
breezes over the Arizona border country will combine with low 
humidities to produce some fire weather concerns...with a similar 
story over the Rio Grande Valley. 


For Saturday...southwest flow aloft and at the surface as surface 
trough extends from low over eastern Colorado back to the south 
and west toward El Paso...and westward to the lower Colorado River 
valley in western Arizona. Little change to the convective picture 
out east...with lifted indices falling to 5 below...and MUCAPE 
running around 1500 j per kg. Coverage will continue from the 
Central Mountain chain east to the Texas and Oklahoma 
borders...with things remaining dry over the west. Usual afternoon 
southwest breezes will redevelop over the western tier near the 
Arizona line...with fire weather concerns through Saturday 
evening. Otherwise...a steady temperature profile with daytime 
maximum temperatures remaining above normal. 


For Sunday...southwest flow aloft strengthening as surface trough 
deepens from the Nebraska Panhandle across eastern New Mexico to 
the Texas Big Bend country and northern Chihuahua. With dry line 
retreating back to the east...and deepening trough providing 
sharper focus for convection...coverage Sunday will not extend as 
far west as in previous days...with most thunderstorm focus on the 
Texas border country heading into Sunday evening where lifted 
indices are running about 6 below and MUCAPE remains around 1500 j 
per kg. Some cooler air working in from the west will push 
maximum temperatures down a little...but most spots will remain 
normal or better. Remaining 6 to 12 degrees above normal in the 
east. 


Outlook...Memorial Day through Wednesday...southwest flow regime 
continuing aloft with eastern surface trough for Memorial Day with 
dry line and surface trough axis now mostly in Texas leaving just 
a skinny strip of thunderstorm potential in the eastern tier of 
counties. Shortwave will blast across the California coast and 
nudge into The Four Corners on Tuesday...with some showers and 
thunderstorms possible over the northwest corner of the state by 
Tuesday evening....and this coverage expanding eastward over the 
northern mountains through Wednesday evening as the trough swings 
through northern New Mexico. Cloud cover and cooler air under the 
shortwave will cool things below normal in the west...with temperatures 
remaining near normal or a few degrees more in the east. Afternoon 
southwest breezes will follow the trough passage...starting in the 
west on Memorial Day...develop over the central areas on 
Tuesday...and end up in the east on Wednesday. 


Shy 


Fire weather... 


.Continued very dry and very unstable central and west through 
Saturday... 


Little change in the large scale pattern with a large upper level 
low still centered over the Pacific northwest and shortwave ridging 
with an axis just east of New Mexico. Though some middle and high 
moisture moved over the state late Wednesday...another well defined 
dry slot is approaching from the west. Another day of very deep 
mixing expected...likely above 500 mb...thus breezy southwest winds 
will develop across the western and central zones this afternoon. 
Red flag warning remains in place for the northwest Highlands... 
particularly near the Arizona border...with minimum relative humidity values into 
the single digits once again. However...will likely see spotty 
critical fire weather conditions and super Haines across much of 
western and central zones today...but duration is not long enough to 
warrant a red flag warning. Across the eastern plains south to east 
surface winds will usher in higher dew points...especially 
northeast...and isolated dry line thunderstorms with some wetting 
rain will develop by afternoon. Temperatures 5 to 10 degrees above 
seasonal levels all zones. 


Mostly poor to fair overnight relative humidity recoveries will continue central 
and east but recoveries will be excellent in the eastern plains 
where some low clouds or patchy fog could develop in the predawn 
hours. 


On Friday the upper level low deepens a bit across the west as the 
ridge strengthens to our east. Therefore...the west to east 
gradient in moisture will be greatest. Few changes in the west with 
very dry...very unstable and a few hours of spotty critical fire 
weather conditions expected. Increased surface dew points and 
precipitable water east with isolated to scattered wetting rain in 
the form of showers and thunderstorms. Overnight relative humidity recoveries will 
range from poor to fair central and west to excellent east. 


Little change Saturday with very dry and unstable conditions central 
and west and a slight chance of wetting rain associated with a dry 
line east. Extended models vary somewhat in the strength and 
position of the upper low Sunday through early next week. 
However...the upper trough is expected to deepen by early next week 
over the western states...with an increasing southwest gradient 
ahead of the trough. The west remains very dry through this period while 
precipitation chances decrease across the east on Sunday and move 
east of the state by Monday with single digit afternoon relative humidity values 
expected all zones. 


05 


&& 


Abq watches/warnings/advisories... 
red flag warning from 1 PM this afternoon to 8 PM MDT this evening 
for the following zones...nmz105. 


&& 


$$ 


Shy