TACTICAL FORECAST GRIDS

Decision Support at the Microscale

How good is “good enough?” Research conducted in microscale

meteorology suggest variations of 20 F and tens of knots are not uncommon at spatial scales less than 1 mile.

Crosstimbers Micronet

See: ams.confex.com/ams/pdfpapers/103127.pdf by M.J. Haugland

Crosstimbers Micronet

Temperature(comparison between Micronet and nearby Mesonet sites)

MATT HAUGLAND

Pasture-Level Influences

Note the cold anomaly mid-way between two Mesonet sites spaced 20 miles apart!

Why does it matter?

Mount Scott(~2400 ft)

Medicine Creek

(~1500 ft)

Trains, Trucks, and Mountains

Trucks(~1230 ft) Trains

(~750 ft)

What about NDFD Grids?

What if…

We could accurately forecast with 2500 times more detail?

Account for local mesoscale circulations? What if we could account for land use and

urbanization? Update the forecast each hour? Produce tailored decision support forecast

content?

Tactical Forecast Grids

Tactical Forecast Grids

Tactical Forecast Grids

100 m grid spacing 50 X 50 km moveable tactical domain Updated hourly Hourly forecast to 8 hours Time of request to forecast product ~15

minutes

NDFD vs. TFG – A Comparison

Tactical Forecast Grids

How do we do that?

LAPS5000m2X hr-1

Mesonet

Topo1000m

RUC

Metars

WFO WRF4000m1X hr-1

NAMLateral

Boundary

Topo1000m

VegetativeFraction

(Satellite)

LandUse

GFE 100m

HAZMATFire

SupportTacticalForecast

Topo30m

Forecaster Expertise

QC,SA

Tactical model configuration, domain grid

selection

QC, Smart Tools,Decision Support

Expert

Tactical Grid Forecast Process

RUC13

Alte

rnat

ive

LAPS Domain

WRF Domain

LAPS, WRF, TFG Domains

Tactical Forecast Grids

They look pretty, but are they any good?

The Fort Cobb Project ARS Ft. Cobb

Micronet5 min T,Td15 stations

Compared T, Td between NDFD and TFG at stations

Jan 9 – Feb 28, 2009Around clock

Results

12240 temperature forecast pairs TFG improved over NDFD 75% of the

time MAE was about 40% improved in TFG

(about 1.3 deg F) MAE improvement was consistent night

and dayMAE slightly larger at night

MAE at 01Z

F101 F102 F103 F104 F105 F106 F107 F108 F109 F110 F111 F112 F113 F114 F115

Hires

1.81617647058824

1.76838235294118

2.37132352941176

1.83088235294118

1.63235294117648

1.875 1.58455882352941

1.64705882352941

1.89705882352941

4.15073529411765

1.70588235294118

2.51838235294118

1.73161764705882

1.38970588235294

1.47426470588235

NDFD

3.29411764705883

3.58455882352941

3.5220588235294

2.77573529411765

3.02941176470588

3.375 2.85294117647058

3.09191176470588

2.625 4.63235294117647

2.92279411764706

2.875 2.72426470588237

2.76470588235295

2.41544117647058

0.25

0.75

1.25

1.75

2.25

2.75

3.25

3.75

4.25

4.75

MAE 01Z Accumulation Per Site

Hires

Site Location

oF

MAE at 21Z

F101 F102 F103 F104 F105 F106 F107 F108 F109 F110 F111 F112 F113 F114 F115

Hires

1.47426470588235

1.79044117647059

1.31985294117647

1.8125 1.47426470588235

1.33455882352941

1.52205882352941

1.53676470588235

2.16176470588237

1.99632352941177

1.27573529411764

1.44485294117647

1.28308823529412

1.88970588235294

1.33823529411765

NDFD

3.20220588235294

3.25367647058823

2.91544117647058

2.71323529411765

2.91911764705882

3.01470588235294

2.83088235294118

2.8639705882353

2.47794117647059

3.33823529411765

2.56985294117647

2.60661764705882

2.4375 2.43382352941176

2.42279411764706

0.25

0.75

1.25

1.75

2.25

2.75

3.25

3.75

21 Z MAE Accumulation Per Site

Hires

Site Location

oF

Future Work

Explore techniques to improve WRF initialization

Refine Smart-Init Expand domains Run farther in time Develop GIS compatible formats

Tactical Forecast Grids

What are the implications for NWS services?

Implications – Services

More accurate short-term forecastsFire weather, dispersion, HAZMAT, special

event support, simulating local effects for forecast decisions (e.g. freeze warnings)

The tactical forecast

Tactical Forecast

Generated by Tactical GFE formatter Includes ALOHA parameters Disseminated via email to event-specific

customer list.

TTAA00 KOUN 061612 TACOUN TACTICAL DECISION SUPPORT FORECAST NATIONAL WEATHER SERVICE NORMAN OK 1012 AM CST FRI MAR 6 2009 .INCIDENT...DEWEY CO WILDFIRE .FORECAST... TIME (CST) 1000 1100 1200 1300 1400 1500 1600 1700 WIND SPEED (KT) 4 G5 5 G9 7 G11 10 G16 11 G18 12 G19 WIND DIR (DEG) 129 166 195 199 207 209 SKY (%) 60 60 60 60 60 60 TEMPERATURE (F) 59 62 67 70 74 76 STABILITY CLASS C C C C D D REL. HUMIDITY (%) 18 20 21 22 21 21 DEWPOINT (F) 16 21 26 29 32 33 1KFT WIND (MPH) S 4 S 6 S 11 S 14 SW 15 SW 18 2KFT WIND (MPH) SW 11 SW 14 SW 20 SW 24 SW 20 SW 20 3KFT WIND (MPH) W 17 SW 17 SW 21 SW 25 SW 27 SW 26 MIXING HGT (FT) 1023 1496 2176 2564 3178 3754 TRANS WIND (KT) SW 5 S 7 S 10 S 15 SW 15 SW 18 N/A N/A HEAT INDEX WIND CHILL 59 62 67 70 74 76 .LAT/LON...36.03/-98.96 $$

Tactical Forecast

Georeferenced formatsGeoTiffShapefiles

○ Highlight areas using thresholds important to decision-makingRegions and times below freezingRegions and times of poor dispersionRegions and times of dangerous wildfire spread

indexAnd so on

Implications - Operations Redefines the role of the forecaster and the

forecast processToo detailed and rapid-paced for hand editsForecaster becomes an advisor to decision

makersForecaster needs to be expert in mesoscale

and microscale meteorology Easily transportable throughout NWS field

Can be customized to meet local needsExpertise to implement already exists in many

offices

QUESTIONS?