EWP STATUS FOR 7 MAY 2013: 1 – 9 PM SHIFT

On Tuesday, forecast parameters look favorable for the development of severe thunderstorms in west Texas.  Strong directional shear will combine with weak to moderate instability to support a risk for elevated supercells.   Given the lack of quality moisture, the tornado threat should be minimal.  However, steep lapse rates and adequate moisture should result in a  large hail threat.   Additionally, a significant damaging wind threat may develop as forecast thermodynamic profiles show the classic “inverted V” shape.

Despite limited upper-level forcing, severe thunderstorms should develop by mid-afternoon.  The combination of upslope flow with seasonably-strong diabatic heating should result in the elimination of the cap by mid-afternoon.  Storms will likely organize into supercells by mid-evening, with a transition to mesoscale convective system possible later on.   However, forcing from an approaching upper-tropospheric shortwave trough will be limited before 06Z, so storms may be diurnally driven.
CWAs Likely to See Operations: Amarillo and Lubbock

-G. Garfield, Week 1 Coordinator

EWP STATUS FOR 14 JUNE 2012: 1-9 p.m. SHIFT

On Thursday, we will begin our shift at 1 p.m.  The operational models depict a strong, negatively-tilted shortwave trough entering the Upper Midwest by early afternoon.  The associated strong deep-layer shear and moderate instability will support supercells/organized convection in Minnesota and Wisconsin during the afternoon/evening hours.   Given moderate low-level shear and low LCLs, a tornado threat may emerge as well.  However, this may be tempered by a relatively quick transition to the linear convective mode, owing to the strong forcing associated with the ejecting upper trough.  Current thinking is that the Duluth, Minneapolis, and LaCrosse county warning areas are the most likely candidates for severe operations.

– G. Garfield, Week 5 Coordinator

EWP STATUS FOR 12 JUNE 2012: 1-9pm SHIFT

On Tuesday, we will begin our shift at 1 p.m.  The NAM depicts a weak shortwave trough entering the southern High Plains by mid-afternoon.  Forecast thermodynamic and kinematic profiles strongly support supercells, given convective initiation.  All modes of severe will be possible (wind, hail, and tornadoes), given the degree of low-level CAPE and low-level shear.  At this time, the Midland, Lubbock, Albuquerque, and Pueblo CWAs are the most likely candidates for severe operations.   Given the geography of the severe threat, the OUN WRF and the Lightning Mapping Array platforms are likely to be evaluated.

– G. Garfield, Week 5 Coordinator

EWP STATUS FOR 7 JUNE 2012: 1-9pm SHIFT

We expect operations will again be focused in NE CO/SE WY.  SPC also has a 5% hail contour that clips the N part of the DC LMA, so we may focus on that early on.

We plan to wrap up operations around 7:30pm and then spend and hour and a half on surveys and preparation for Friday’s webinar.

– T. Smith, Week 4 coordinator

EWP STATUS FOR 6 JUNE 2012: 1-9pm SHIFT

We’ll plan on a 1pm start on Wed.  The most likely areas for operation based on the day 2 SPC outlook and 21Z SREF probabilities are NE Colorado (best chance of supercells) and OK/W TX (for low-shear pulse storms in the Lightning Mapping Array)

– T. Smith, Week 4 coordinator

EWP STATUS FOR 5 JUNE 2012: 1-9pm SHIFT

SPC day 2 outlook has the highest risk (15%) of severe in SE GA/NE FL, where initiation is expected after 18Z.  Another area of 15% is in the NW US.  Both of these areas have the best forecast CAPE/shear, while other areas of the South have lots of CAPE, no cap, and less shear in the model forecasts.  We’ll keep our options open in the event of development in the W TX LMA or other locations.

– T. Smith, Week 4 coordinator

EWP STATUS FOR 24 MAY 2012: 1-9pm SHIFT

Planning on a 1-9pm shift for our final day in the testbed this week…

We will likely be operating in the Iowa / Minnesota / Wisconsin region tomorrow afternoon and evening. Expectation is for isolated storms early before joining into a line / MCS later in the evening with possible embedded supercells.  Hopeful for convection as early as 1800-2100 UTC, although the last few days all the models have seemed to be a bit too aggressive for the timing of convection initiation across the central Plains… However, boundary layer moisture has been a concern the last couple days and may be less of a concern tomorrow.

Another possibility for operations tomorrow may be the Florida domain, which, depending on timing and location, may allow for at least one operational period utilizing lightning data. Or, similar to today, there is also the possibility of multicell convection across eastern NC earlier in the afternoon.

-K. Calhoun, Week 3 Coordinator

EWP STATUS FOR 23 MAY 2012:  1-9pm SHIFT

We will be operating a 1-9 pm shift tomorrow.  Although the cap will probably be an issue earlier in the afternoon, we expect supercell thunderstorms to form by early evening across the south-central Neb  & northern KS.

Another consideration are the data limitations after 9pm.  Since we share supercomputer time with the NSSL-WRF, 3DVAR calculations end at 9 pm.

-Kristin Calhoun, Week 3 Coordinator

EWP STATUS FOR 22 MAY 2012: 2-10pm SHIFT

Currently, it appears that we will be operating in the North Dakota region tomorrow…

Early on, the cap combined with a narrow area of boundary layer moisture (50-60F dewpoints) seem to be a bit of a concern, but forcing associated with a cold front later in the evening should assure convection.  If initiation can occur earlier in the day ahead of the front and along the dryline, shear profiles indicate supercells with large hail will be the most likely mode of convection before transitioning to a line/MCS by the overnight hours.

With the concerns limiting convection earlier in the day, we’ve elected to go with 2-10 pm shift Tues.

-Kristin Calhoun, EWP 2012 Week 3 Coordinator