1996-05-04

SUCCESS 48 hour Meteorological Forecast

 

12z 04 May 1996

Forecast Based on

  • on satellite
  • current surface observations
  • 00 UTC ETA
  • 00 UTC NGM
  • 09 UTC MAPS/RUC
  • MRF
  • 12z ECWMF

 

Synopsis

Persistence sums up the weather. Zonal flow still dominates over the US, with the jet and any strong shortwaves well north of KS. A surface low remains over the panhandle of TX/OK and sw KS, with the east/west stationary front across KS moving slightly to the south over the last 24 hrs.

The satellite pictures were not being updated this morning. The water vapor loop shows a north/south gradient over OK/NM/AZ at 03z and 06z. The cutoff low at 150W has started to move eastward.

Over night, severe convection occurred across KS, bringing strong winds, 1.41'' of rain, and lightening to Salina. One of the convective cells east of Russell produced hail. By 12z all of the convection was east of Salina. A strong cap over OK and a lesser one over KS will prevent convection from occurring today.

 

Prog Discussion

The NGM and ETA agree well, except at 48 hrs where the NGM tries to move the surface low and stationary front. With the flow being zonal, this trend is questionable. The NGM does show the cutoff low in the Pacific being picked up into the westerly flow by 48 hrs. The satellite loop confirms the movement of the low.

With the stationary front across KS or postioned slightly to the south of the state, thunderstorms are likely to occur again this evening.

 

48 hour Forecast:

12z 04 May - 00Z 05 May: Mostly cloudy. Highs ~70. Winds 10-15 kts out of the northeast. Chance of thunderstorms.

00Z 05 May - 12Z 05 May: Chance of thunderstorms, possibly severe. Lows in the mid 50s.

12z 05 May - 12Z 06 May: Chance for some early morning showers. Partly cloudy, with possible clearing. Highs in the 70s.

12z 06 May - 12Z 07 May: Chance of thunderstorms. Highs in the 70s. Lows in the 50s.

Both the MRF and ECMWF pick up the cutoff low in the Pacific and form a trough on the Pacific Northwest, with the trough extending down over northern CA. The ECMWF builds a ridge over the middle of the US by Tues. The model has the ridge axis extending well into Sasskatchewan/Manitoba by Wed./Thur. The MRF does not amplify the ridge as much.

With this pattern and with the possibility of moisture advecting in from the inclusion of the Pacific low, Mon. or Tues. could be good cirrus days at the CART site.

Walker and Mace

 

1996-05-03


SUCCESS 48 hour Meteorological Forecast


12z 03 May 1996

Forecast Based on

  • on satellite
  • current surface observations
  • 00 UTC ETA
  • 00 UTC NGM
  • 09 UTC MAPS/RUC
  • MRF
  • 12z ECWMF

Synopsis


Zonal flow across the entire US. There is still the cut off low out in the Pacific at
150W. There are no apparent ripples in the flow. There are scattered vorticity lobes
of varying intensity through the flow.

A lot of excitement here this morning. Intense convection sprung up in western KS this
morning around 10z. Within a half hour, the top of the cell measured 207 K. As the
morning progressed, more cells popped up toward the east ahead of this main cell. The
convection was heading due east toward Salina. The radar was showing tops of 50,000 ft,
hail, and a meso cyclone for one of the cells. The line of convection was just south of
Salina and Russel. With strong surface convergence in the lower levels and a strong
southerly jet, severe convection broke out along a warm front just south of Salina.

A surface low is centered over the panhandle of TX/OK and sw KS. The winds are
southeasterly and increasing. Overhead, anvil cirrus covers most of the sky, and it
is dark to the southwest.

The water vapor loop shows a moist tongue extending from the southwest over OK and
the CART site. There is a dry slot to the west of this moist tongue; therefore, drying
conditions in the upper troposphere are expected as the day progresses.

Prog Discussion


The models are showing a stationary pattern to the upper level flow and surface fronts.
The ETA and NGM differ a little in the placement of the surface low over TX/OK/KS through
today and tomorrow; but, no matter the placement, a stationary front will be positioned
over KS.

Tomorrow a shortwave is analyzed over KS and northern OK. This shortwave may allow
cirrus to advect in or to form over the CART site.

48 hour Forecast:


12z 03 May - 00Z 04 May: Partly cloudy. Chance for thunderstorms, possibly severe.
Highs in the lower 80s. Winds out of the southeast at 10 kts.

00Z 04 May - 12Z 04 May: Partly cloudy. Chance for showers and thunderstorms. Lows
in the 50s. Winds northeasterly at 5-15 kts.

12z 04 May - 12Z 05 May: A chance for thunderstorms mainly during the early morning and
late afternoon hours. Partly cloudy. High lower/mid 70s. Northeast winds at 10-20 kts.
Chance for thunderstorms in the evening. Lows in the mid 50s.

Extended Range Discussion:


12z 05 May - 12Z 06 May: Partly cloudy. Remote possibility of thunderstorms. High
around 75.

The MRF and ECMWF are both trying to pick up that cut off low in the Pacific and bring
it into the westerly flow. If this verifies, a trough will set up along the west coast,
leaving KS on the front side of it. OK/KS could see some good cirrus and persistent
contrails.

This type of pattern could also lead to severe weather in KS depending on where the surface
low, associated fronts, and upper level jet are located.

Walker and Mace

1996-04-30

SUCCESS 48 hour Meteorological Forecast

 

12z 30 April 1996

Forecast Based on

  • on satellite
  • current surface observations
  • 00 UTC ETA
  • 00 UTC NGM
  • 09 UTC MAPS/RUC
  • MRF
  • 12z ECWMF

 

Synopsis

The longwave trough is positioned over the Mississippi Valley. The backside of the trough is stretched from the Pacific Northwest down to the bottom of the trough over Louisiana/Alabama. The winds aloft are 100 kts over Salina and the CART site. Within the flow at 500 mb are several shortwaves over CO, KS, and NE. Associated with these shortwaves are mid and high level clouds. The cirrus is not as extensive as previously thought over OK.

As the cold front progressed eastward across the South and Gulf, high pressure built in over TX. With off shore flow along the TX coast, clear skies prevail.

Northwestly flow through the depth of the atmosphere and moisture advecting in from the west has lead to wave clouds over the San Cristo Range in NM.

 

Prog Discussion

The upper level flow will remain unchanged over the midwest throughout today and tomorrow. The longwave trough over the Mississippi Valley will flatten and move eastward. Several shortwave impulses will move through the upper level flow over NE, KS, and OK.

Convection south/southeast of Brownsville, TX is looking promising for tomorrow as a weak shortwave moves over the area. At the surface, the pressure gradient is weak, with a weak surface low is analyzed over this region. With this type of surface flow and some upper level support, convection could spring up.

 

48 hour Forecast:

12z 30 Apr - 00Z 01 Apr: Partly cloudy, with 20% chance of showers. Highs in the upper 60s. Southwest winds at 5-15 kts becoming northwesterly in the afternoon at 10-20 kts.

00Z 01 Apr - 12Z 01 Apr: Mostly clear. Low around 40. Northwest wind 5-15 kts.

12z 01 Apr - 12Z 02 Apr: Partly cloudy. High around 70. Northwest wind 5-15 kts becoming west by afternoon.

 

Extended Range Discussion:

12z 02 Apr - 12Z 03 Apr: Dry and mild. Lows in the mid 40s. Highs in the 70s.

After Wed. the upper level flow will become more zonal as the trough to the east weakens and moves off shore. By Saturday, both the MRF and ECMWF start to deepen a trough over the western states.

Walker and Mace

1996-04-27


SUCCESS 48 hour Meteorological Forecast


12z 27 April 1996

Forecast Based on

  • on satellite
  • current surface observations
  • 00 UTC ETA
  • 00 UTC NGM
  • 09 UTC MAPS/RUC
  • MRF
  • 12z ECWMF

Synopsis


The upper level flow is fairly zonal across the US with a hint of the building ridge
off British Columbia and the Pacific northwest coast. A shortwave over KS/OK has led
to some mid level cloudiness. High pressure dominates most of the midwest and all of
the South. A low has formed in New Mexico, and this feature is the one to watch later
today and tomorrow. Satellite imagery shows a jet streak across the US. The water
vapor loop has a dry slot dropping down from the northwest into WY and CO. The Gulf
is free of convection with fog and low level clouds.

There are mid and upper level clouds over KS/OK at this time.

Prog Discussion


All the models are in close agreement in handling the development of the upper level
trough over the Great Basin and the surface low in the TX panhandle in the next 36 hrs.
As the low develops Sat. evening into Sun. morning, the surface dew points will increase
across OK and s/se KS. With strong upper level dynamics, the chance of thunderstorms and
showers in OK is very probable late Sat. night/early Sun. morning. Kansas will have
gusty northeasterly winds, low clouds, and precipitation on Sun. Wide spread
thunderstorms are more likely in the southern and southeastern parts of Kansas.

48 hour Forecast:

12z 27 Apr - 00Z 28 Apr: Partly cloudy. Highs in the mid to upper 60s. Winds northerly
at 10 kts.

00Z 28 Apr - 12Z 28 Apr: Continued cloudiness. Chance of rain. Lows in the mid 40s.
Thunderstorms possible in the southeast. Winds will increase from the northeast.

12z 28 Apr - 12Z 29 Apr: Colder with rain likely in the east and a chance for rain in
the west. Wide spread thunderstorms possible to s and se. Highs ~50. Winds should
20+ kts all day from the northeast.

Extended Range Discussion:


12z 29 Apr - 12Z 30 Apr: Continued cool. Highs in the 50s. Cloudy and chance for rain
in southeast.

The MRF continues to forecast the omega block pattern out to May 6th. The ECMWF showed
a different longwave pattern. Yesterdays ECMWF agreed with the MRF, yet last nights ECMWF
run has the trough progressing to the east and the flow becoming zonal in the next 6 days,
i.e. the persistent pattern since the middle of April.

Walker and Mace

1996-04-27

SUCCESS 48 hour Meteorological Forecast

12z 27 April 1996

Forecast Based on

  • on satellite
  • current surface observations
  • 00 UTC ETA
  • 00 UTC NGM
  • 09 UTC MAPS/RUC
  • MRF
  • 12z ECWMF

 

Synopsis

The upper level flow is fairly zonal across the US with a hint of the building ridge off British Columbia and the Pacific northwest coast. A shortwave over KS/OK has led to some mid level cloudiness. High pressure dominates most of the midwest and all of the South. A low has formed in New Mexico, and this feature is the one to watch later today and tomorrow. Satellite imagery shows a jet streak across the US. The water vapor loop has a dry slot dropping down from the northwest into WY and CO. The Gulf is free of convection with fog and low level clouds. There are mid and upper level clouds over KS/OK at this time.

 

Prog Discussion

All the models are in close agreement in handling the development of the upper level trough over the Great Basin and the surface low in the TX panhandle in the next 36 hrs. As the low develops Sat. evening into Sun. morning, the surface dew points will increase across OK and s/se KS. With strong upper level dynamics, the chance of thunderstorms and showers in OK is very probable late Sat. night/early Sun. morning. Kansas will have gusty northeasterly winds, low clouds, and precipitation on Sun. Wide spread thunderstorms are more likely in the southern and southeastern parts of Kansas.

 

48 hour Forecast:

12z 27 Apr - 00Z 28 Apr: Partly cloudy. Highs in the mid to upper 60s. Winds northerly at 10 kts.

00Z 28 Apr - 12Z 28 Apr: Continued cloudiness. Chance of rain. Lows in the mid 40s. Thunderstorms possible in the southeast. Winds will increase from the northeast.

12z 28 Apr - 12Z 29 Apr: Colder with rain likely in the east and a chance for rain in the west. Wide spread thunderstorms possible to s and se. Highs ~50. Winds should 20+ kts all day from the northeast.

 

Extended Range Discussion:

12z 29 Apr - 12Z 30 Apr: Continued cool. Highs in the 50s. Cloudy and chance for rain in southeast.

The MRF continues to forecast the omega block pattern out to May 6th. The ECMWF showed a different longwave pattern. Yesterdays ECMWF agreed with the MRF, yet last nights ECMWF run has the trough progressing to the east and the flow becoming zonal in the next 6 days, i.e. the persistent pattern since the middle of April.

Walker and Mace

1996-04-26


SUCCESS 48 hour Meteorological Forecast


12z 26 April 1996

Forecast Based on

  • on satellite
  • current surface observations
  • 00 UTC ETA
  • 00 UTC NGM
  • 09 UTC MAPS/RUC
  • MRF
  • 12z ECWMF

Synopsis


A very low amplitude ridge is analyzed over Montana and eastern Wyoming with a trough
to the east over the Mississippi Valley. The satellite loop shows these features. The
water vapor imagery shows a distinct dry slot across the Gulf. A shortwave is located
at 45N, 130W. High pressure is over the eastern Rockies. A fairly weak gradient has
formed over the midwest with the winds out of the north at 10-15 kts.

Prog Discussion


As the Pacific northwest shortwave moves on shore and through the Rockies, the upper
level ridge will flatten entirely. By 36 hours, a ridge starts to build at 135W. As
the ridge amplifies, a trough forms over the Great Basin with several shortwaves embedded
in the flow. Both the ETA and NGM form a surface east of the Rockies. The ETA forms
a surface low in TX panhandle while the NGM puts it over NE/MO. This type of pattern
will lead to strong southerly winds laden with Gulf moisture. Kansas and Oklahoma could
see some showers late Saturday night.

48 hour Forecast:

12z 26 Apr - 00Z 27 Apr: Mostly sunny. Maybe some high clouds. Highs upper 60s.
Winds light (10 kts) from the northwest.

00Z 27 Apr - 12Z 27 Apr: Increasing clouds. Lows in the low to mid 40s. Winds
out of the southwest 10-20 kts.

12z 27 Apr - 12Z 28 Apr: Breezy and mostly cloudy. High around 70. North wind
15 to 25 kts and gusty.

12z 28 Apr - 12Z 29 Apr: Good chance for showers. Lows in the mid 40s. Highs in
the mid to upper 60s.

For the long range outlook, both the MRF and the ECMWF are depicting an omega block
pattern over the eastern Pacific and west coast. A trough sets up over the Mississippi
Valley which leaves the midwest on the backside of the trough. The latest ECMWF run
goes out to May 1 and the MRF run out to May 6. Both models show the omega block
lasting through to the end of these forecast periods.

Walker and Mace

1996-04-24


SUCCESS 48 hour Meteorological Forecast


12z 24 April 1996

Forecast Based on

  • on satellite
  • current surface observations
  • 00 UTC ETA
  • 00 UTC NGM
  • 09 UTC MAPS/RUC
  • MRF
  • 12z ECWMF

Synopsis


An upper level ridge is analyzed over the northern Plains. A surface trough extends
from northeastern NE to western TX. The winds are southerly at 15-20 kts. The satellite
picture shows plenty of upper level moisture over the Rockies with cirrus streaming
over KS and OK.

Prog Discussion


Two strong shortwaves (one over southern Alberta, the other at 45N, 130W) will flatten
the upper level ridge and dig a trough over the midwest in the next 48 hours. A strong
pressure gradient will form the Rockies through the Plains as deep surface low tracks
across the northern Plains. The winds will be strong and gusty today and tomorrow. A
cold frontal passage on the morning of April 25 will result in the southerly winds
shifting to strong northwestly winds. With the abundant moisture from the former Pacific
northwest system, cirrus clouds will persist today and tomorrow. Mid level clouds will
form after the frontal passage. The skies will clear late in the afternoon on the 25th.

48 hour Forecast:

12z 24 Apr - 00Z 25 Apr: Highs in the 70s. Winds out of the southwest at 20 kts.
Persistent cirrus of varying thickness.

00Z 25 Apr - 12Z 25 Apr: Lows in the upper 40s. The front will pass around midnight.
The winds will shift from southwestly to northwesterly.

12z 25 Apr - 12Z 26 Apr: Cooler temperatures: upper 60s. Winds from the northwest at
20+ kts gusting to 30 kt. Early morning, mid and upper level cloudiness. Clearing
in the late afternoon.

Extended Range Discussion:


12z 26 Apr - 12Z 27 Apr: The upper level trough will progress to the eastcoast. Kansas
will be in an area of subsidence. High pressure will build in after the front causing
light winds and clear skies. Temperatures in the ~70.

Walker and Mace

1996-04-23


SUCCESS 48 hour Meteorological Forecast


12z 23 April 1996

Forecast Based on

  • on satellite
  • current surface observations
  • 00 UTC ETA
  • 00 UTC NGM
  • 09 UTC MAPS/RUC
  • MRF
  • 12z ECWMF

Synopsis


A tightly wound up surface low in the Gulf of Alaska is associated with a
strong shortwave and upper level jet on the Pacific Northwest coast. Plently
of mid and upper level moisture exists with this feature. Cirrus is spilling
over the ridge which is ahead of the Pacific trough into ID, MT, and WY. With
these conditions, wave clouds are expected to form along the Front Range and
over Medicine Bow.

Over Kansas, high pressure has built in. The winds are light, and the skies
are blue.

Prog Discussion


As the Pacific Northwest shortwave moves on shore and into the Rockies, the ridge
will progress eastward and start to deamplify. By 00Z Thu 25, the 500 mb
flow will almost be zonal. At the surface, the high will slide down into Texas
and the Gulf. As the shortwave moves eastward, a surface low forms in the northern
Plains with a trough forming in the lee of the Rockies.

48 hour Forecast:

12z 23 Apr - 00Z 24 Apr: Sunny skies with thin upper level clouds increasing toward
the evening. Highs in the 70s. Winds southerly 10 kts.

00Z 24 Apr - 12Z 24 Apr: Increasing cirrus. Lows in the lower 50s. Winds out of
the south 10-15 kts.

12z 24 Apr - 12Z 25 Apr: Partly cloudy. Cirrus will vary in cover and thickness.
Warm and windy: upper 70's, southwestly winds 20+ kts.

Extended Range Discussion:


12z 25 Apr - 12Z 26 Apr: Trough will form over the midwest. After cold frontal
passage on morning of 25th, temperatures will taper by 10 or more degrees. The
winds will be out of the northwest at 15-20 kts. Some mid level clouds.

Walker and Mace

1996-04-21


SUCCESS 48 hour Meteorological Forecast


12z 21 April 1996

Forecast Based on

  • on satellite
  • current surface observations
  • 00 UTC ETA
  • 00 UTC NGM
  • 09 UTC MAPS/RUC
  • MRF
  • 12z ECWMF

Synopsis


A broad trough with numerous embedded shortwaves from the Rockies to
the Central Plains is controlling the weather over the area. At the surface,
an inverted surface trough has formed to the lee of the Rockies with a warm front
extending from a low in southwestern Texas to the upper Ohio valley. A strong
low level jet is associated with this trough and is pumping Gulf air into central
Texas on up to the Red River. An east/west dryline on the Red River Valley will
turn counter-clockwise through the day. Strong convection will spring up along
this boundary with severe thunderstorms becoming more likely into the late afternoon
and evening. Tornadoes may occur. Convection occurred in southwestern Kansas last
night, but the state will not receive any more precipitation.

Prog Discussion



A shortwave over the central Plains is producing mid and high level
clouds. As this shortwave exits the region to the northeast, an associated surface
low will track across Kansas. Upstream there is a shortwave over southern CA/western
AZ border that will rotate around and deepen the the 500 mb trough. This shortwave
will drive convection along a front which will connect from a surface low in the
northern Plains to a low that is moving eastward across Texas. Both high and mid
level cloudiness will prevail today and tomorrow.

48 hour Forecast:

12z 21 Apr - 00Z 22 Apr: High and mid level cloudiness. As the surface low progresses
across Kansas, the wind will shift from southerly to northernly in the late afternoon.
Speeds of 15 kts. Highs in the low 70s.

00Z 22 Apr - 12Z 22 Apr: Partly cloudy and cool. Low in the 40s. Northwesterly winds
of 15 kts.

12z 22 Apr - 12Z 23 Apr: Partly cloudy and cool. Highs in the mid 50s. Decreasing
winds during day.

Extended Range Discussion:


12z 23 Apr - 12Z 24 Apr: Amplifying trough will progress eastward leaving KS and OK
on the backside of the trough by Wednesday morning. Depending on the speed of trough,
ridge cirrus could be spilling over by Tues, but more likely on Wed. Daytime high in
the mid 60s.

Walker and Mace

1996-04-20


SUCCESS 48 hour Meteorological Forecast


12z 20 April 1996

Forecast Based on

  • satellite
  • current surface observations
  • 00 UTC ETA
  • 00 UTC NGM
  • 09 UTC MAPS/RUC
  • MRF
  • 12z ECWMF

Synopsis


The upper level flow is split at 140W. The southern branch of the jet is zonal and extends
from 140W to the Mississippi Valley. A surface low has formed in the four corners area with
a shortwave analyzed over it. The satellite picture is showing cirrus and mid-level clouds
from AZ to eastern NM. Presently, the skies are clear over Salina and the CART site.

Prog Discussion



The broad upper level flow pattern is going to change in the next 48 hours as a ridge builds
in at 122W and a trough sharpens at 102W. The shortwave over AZ will travel through the
bottom of the flat 500 mb trough and track to the northeast by 00Z Sun 21. Upstream, a
rigorous Pacific Northwest shortwave will deepen the 500mb trough as it traverses and exits
the Rockies. A surface low will form in western KN and will move northeastward across the
state from 12Z-00Z Sun 21/Mon 22. Precipitation, low, and mid level clouds are associated
with this system. A surface front extending from southeastern OK back across TX could lead
to convection over this region.

48 hour Forecast:

12z 20 Apr - 00Z 21 Apr: High level clouds are expected over southern KS and OK. Temperatures
in the 70s. Wind 10 kt out of the south.

00Z 21 Apr - 12Z 21 Apr: Low level clouds increasing through the night. Low in the upper
40s. Wind becoming southeast at 10-15 kts.

12z 21 Apr - 12Z 22 Apr: Rain likely in northwestern and north central KS. High around 70.
Winds westerly turning to the northwest by the afternoon. Could be gusty after the front
passes. Sunday night: cooler and mostly cloudy. Temperatures in low to mid 40s.

Extended Range Discussion:


12z 22 Apr - 12Z 23 Apr: Continued cool and cloudy.

Walker and Mace

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